153 results on '"Bos NA"'
Search Results
2. Migration of Antigen-Presenting B Cells from Peripheral to Mucosal Lymphoid Tissues May Induce Intestinal Antigen-Specific IgA Following Parenteral Immunization
- Author
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Coffin, SE, Clark, SL, Bos, NA, Brubaker, JO, Offit, PA, and Translational Immunology Groningen (TRIGR)
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CD4(+) T-CELLS ,MICE ,LYMPHOCYTES-T ,IMMUNE-RESPONSES ,GERMINAL-CENTERS ,Immunology ,VIRUS ,POPULATIONS ,Immunology and Allergy ,DENDRITIC CELLS ,ROTAVIRUS INFECTION ,ANTIBODY-PRODUCTION - Abstract
Parenterally administered immunizations have long been used to induce protection from mucosal pathogens such as Bordetella pertussis and influenza virus. We previously found that i.m. inoculation of mice with the intestinal pathogen, rotavirus, induced virus-specific Ab production by intestinal lymphocytes. We have now used adoptive transfer studies to identify the cell types responsible for the generation of virus-specific Ab production by gut-associated lymphoid tissue (GALT) after i.m. immunization. Three days after i.m. immunization with rotavirus, cells obtained from the draining peripheral lymph nodes of donor mice were transferred into naive recipient mice. We found that intestinal lymphocytes produced rotavirus-specific Igs (IgM, IgA, and IgG) 2 wk after transfer of either unfractionated cells, or unfractionated cells rendered incapable of cellular division by mitomycin C treatment. Additional studies demonstrated that rotavirus-specific IgA, but not IgG, was produced by intestinal lymphocytes after transfer of purified B cells. Ig allotype analysis revealed that rotavirus-specific IgA was produced by intestinal B cells of recipient origin, suggesting that migration of Ag-presenting B cells from peripheral lymphoid tissues to GALT may contribute to the generation of mucosal IgA responses after parenteral immunization. Strategies that promote Ag uptake and presentation by B cells may enhance mucosal IgA production following parenteral immunization.
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- 1999
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3. Sending and signaling by the immune system NVVI-Dutch Society for Immunology Course, April 2-3, 2009
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Wauben, MHM, Toes, REM, Bos, NA, Damoiseaux, J, van Ham, SM, van de Loosdrecht, AA, Samsom, Janneke, and Pediatrics
- Published
- 2010
4. Restricted IgA repertoire in both B-1 and B-2 cell-derived gut plasmablasts
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Stoel, M, Jiang, HQ, van Diemen, CC, Bun, JCAM, Dammers, PM, Thurnheer, MC, Kroese, FGM, Cebra, JJ, Bos, NA, Groningen Institute for Gastro Intestinal Genetics and Immunology (3GI), and Translational Immunology Groningen (TRIGR)
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SECRETING CELLS ,B-CELL ,COMMENSAL BACTERIA ,INTESTINAL IGA ,MUCOSAL IMMUNE-SYSTEM ,VIRUS-INFECTION ,V-H GENES ,T-CELL ,DEFICIENT MICE ,IN-VIVO - Abstract
Mucosal IgA is the most abundantly produced Ig upon colonization of the intestinal tract with commensal organisms in the majority of mammals. The repertoire of these IgA molecules is still largely unknown; a large amount of the mucosal IgA cannot be shown to react with the inducing microorganisms. Analysis of the repertoire of used H chain Ig (V-H) genes by H-CDR3 spectrotyping, cloning, and sequencing of V-H genes from murine intestinal IgA-producing plasma cells reveals a very restricted usage of V-H genes and multiple clonally related sequences. The restricted usage of V-H genes is a very consistent observation, and is observed for IgA plasma cells derived from B-1 or conventional B-2 cells from different mouse strains. Clonal patterns from all analyzed V-H gene sequences show mainly independently acquired somatic mutations in contrast to the clonal evolution patterns often observed as a consequence of affinity maturation in germinal center reactions in peripheral lymphoid organs and Peyer's patches. Our data: suggest a model of clonal expansion in which many mucosal IgA-producing B cells develop in the absence of affinity maturation. The affinity of most produced IgA might not be the most critical factor for its possible function to control the commensal organisms, but simply the abundance of large amounts of IgA that can bind with relatively unselected affinity to redundant epitopes on such,organisms.
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- 2005
5. MRC OX19 RECOGNIZES THE RAT CD5 SURFACE GLYCOPROTEIN, BUT DOES NOT PROVIDE EVIDENCE FOR THE PRESENCE OF A DISTINCT CD5 POSITIVE B CELL POPULATION IN THE RAT
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VERMEER LA, DE BOER NK, BOS NA, KROESE FG, ALBERTI S., BUCCI, Cecilia, Vermeer, La, DE BOER, Nk, Bucci, Cecilia, Bos, Na, Kroese, Fg, and Alberti, S.
- Subjects
immune system diseases ,hemic and lymphatic diseases - Abstract
To clone the rat CD5 gene we first produced two rat CD5 probes. The probes were obtained by polymerase chain reaction (PCR) on rat genomic DNA using primers designed on conserved regions between mouse and human CD5. The screening of a rat cDNA library at high stringency using these probes resulted in a 1.5-kb positive clone. The DNA sequence of this clone confirmed its CD5 nature, but the clone appeared to lack part of the 5' and part of the 3' end. These missing 5' and 3' ends were obtained by PCR on rat thymus RNA. By ligating these PCR products to the original 1.5-kb CDM8 clone, a full-length rat CD5 gene was constructed. The full-length clone showed high identity with mouse and human CD5; however, at the 5' site of the gene a region of 36 nucleotides is present which is not seen in either mouse or human CD5. We have evidence that this sequence is a normal constituent of the rat CD5 gene: first, it is in frame with the rest of the CD5 coding sequence; second, it does not contain a stop codon; and third, it is also present in the CD5 gene of other rat strains. We transfected the full-length CD5 construct in COS cells and demonstrated that indeed the CD5 protein is recognized by MRC OX19. Although we showed that CD5 mRNA is present in rat B cells, extensive flow cytometry analysis using MRC OX19 as antibody failed to detect B cells expressing significant levels of CD5 on their cell surface compared to other B cells in any tissue or cell suspension tested from a variety of rat strains. This is in contrast with the mouse where a distinct population of B cells (B-1a cells) can be found expressing more CD5 than the other B cells. Either B-1 cells are not present in rats or CD5 is not the right phenotypic marker for rat B-1 cells. It still remains to be investigated whether a population of B cells with functions similar to those of murine B-1 cells is present in rats.
- Published
- 1994
6. Injection of recombinant Fc alpha RI/CD89 in mice does not induce mesangial IgA deposition
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van der Boog, PJM, van Kooten, C, van Zandbergen, G, Klar-Mohamad, N, Oortwijn, B, Bos, NA, van Remoortere, A, Hokke, CH, de Fijter, JW, Daha, MR, and Translational Immunology Groningen (TRIGR)
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EXPRESSION ,IDENTIFICATION ,NEPHROPATHY ,receptor ,GLYCOSYLATION ,IgA nephropathy ,LYMPHOCYTES ,ALPHA-RECEPTOR CD89 ,IMMUNOGLOBULIN (IG)A1 ,CELLS ,FC-RECEPTOR ,COMPLEXES ,CD89 ,IgA ,mouse - Abstract
Background. Earlier studies have suggested that complexes of the human IgA receptor FcalphaRI/CD89 with mouse IgA are pathogenic upon deposition in the renal mesangium. Transgenic mice expressing FcalphaRI/CD89 on macrophages/monocytes developed massive mesangial IgA deposition and a clinical picture of IgA nephropathy (IgAN). Based on these findings, the purpose of this study was to design an experimental model of IgAN by injection of human CD89 in mice. The interaction of mouse IgA with CD89 was investigated further. Methods. Recombinant human soluble CD89 and a chimeric CD89-Fc protein were generated, produced, purified and injected in mice. Renal cryosections were stained for IgA and CD89. The interaction of mouse IgA with CD89 was analysed by fluorescence-activated cell sorting (FACS) analysis, enzyme-linked immunosorbent assay (ELISA) and plasmon resonance technology. Results. Injection of recombinant human CD89 did not result in significant IaA or CD89 deposition in the renal mesangium. However, CD89 staining in the liver was found to be positive. CD89 was rapidly cleared from circulation without signs of complex formation with IgA. FACS analysis, ELISA and plasmon resonance techniques all revealed a dose-dependent binding, of human IgA to recombinant CD89, while no detectable binding was seen of Mouse IgA. either of serum IgA or of different monoclonal mouse IgA preparations. Conclusions. An experimental model for IgAN in mice could not be obtained by injection of recombinant CD89. This is compatible with our in vitro biochemical data showing a lack of binding between recombinant human CD89 and mouse IgA.
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- 2004
7. The origin of autoantibodies
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Benner, Rob, Bos, NA (Nico), Heidt, PJ, Berg, RD, Rusch, V, van der Waaij, D, and Immunology
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- 2004
8. CD27-triggering on primary plasma cell leukaemia cells has anti-apoptotic effects involving mitogen activated protein kinases
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Guikema, JEJ, Vellenga, E, Abdulahad, WH, Hovenga, S, Bos, NA, Other departments, Guided Treatment in Optimal Selected Cancer Patients (GUTS), Stem Cell Aging Leukemia and Lymphoma (SALL), and Translational Immunology Groningen (TRIGR)
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TERMINAL KINASE ,NF-KAPPA-B ,apoptosis ,p38 ,extracellular-regulated kinase 1/2 ,CD27 EXPRESSION ,MULTIPLE-MYELOMA CELLS ,P38 MAP KINASE ,CD27/CD70 INTERACTION ,COMPARATIVE GENOMIC HYBRIDIZATION ,SIGNAL-REGULATED KINASE ,INDUCED INHIBITION ,plasma cell leukaemia ,GLUCOCORTICOID-INDUCED APOPTOSIS ,CD27 - Abstract
Primary plasma cell leukaemia (PCL) is a rare plasma cell malignancy, which is related to multiple myeloma (MM) and is characterized by a poor prognosis. In a previous study we demonstrated that PCL plasma cells display a high expression of CD27, in contrast to MM plasma cells. The present study was set out to assess the functional properties of CD27 expressed on PCL plasma cells by triggering with its ligand CD70. Using CD27-expressing purified plasma cells from a PCL patient we demonstrated that CD27-triggering modestly inhibited spontaneous and dexamethasone-induced apoptosis. In vitro stimulation and Western blotting showed that activation of p38 and extracellular-regulated kinase 1/2 (ERK1/2) mitogen-activated protein kinases (MAPK) was associated with CD27-mediated signal transduction. Specific inhibition of p38 and ERK1/2 MAPK abolished the anti-apoptotic effects of CD27-triggering. Interestingly, simultaneous inhibition of p38 and ERK1/2 strongly sensitized PCL cells for dexamethasone-induced apoptosis. Finally, in dexamethasone-treated PCL cells, CD27-triggering was associated with persistent DNA-binding activity of activator protein 1 (AP-1) but not of nuclear factor-kappaB. These findings suggest that, in primary PCL, specific anti-apoptotic pathways exist that might provide novel therapeutic targets.
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- 2004
9. CD27 is heterogeneously expressed in multiple myeloma: low CD27 expression in patients with high-risk disease
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Guikema, JEJ, Hovenga, S, Vellenga, E, Conradie, JJ, Abdulahad, WH, Bekkema, R, Smit, JW, Zhan, FH, Shaughnessy, J, Bos, NA, Other departments, Faculteit Medische Wetenschappen/UMCG, Guided Treatment in Optimal Selected Cancer Patients (GUTS), Stem Cell Aging Leukemia and Lymphoma (SALL), and Translational Immunology Groningen (TRIGR)
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cDNA microarray ,ANTIGEN ,chemical and pharmacologic phenomena ,hemic and immune systems ,GENE FAMILY ,multiple myeloma ,DIFFERENTIATION ,immunophenotyping ,immune system diseases ,CD27/CD70 INTERACTION ,MARKER ,MEMORY B-CELLS ,NORMAL PLASMA-CELLS ,GROWTH ,LIGAND ,CD27 ,TUMOR-NECROSIS-FACTOR - Abstract
Expression of CD27 on malignant plasma cells (PC) (CD138(+) CD38(++) ) was analysed in a cross-sectional study of bone marrow (BM) samples from multiple myeloma (MM) patients (n = 28), monoclonal gammopathy of undetermined significance (MGUS) patients (n = 6) and BM PC from healthy donors (n = 4). MM PC expressed CD27 with a variable, lower intensity pattern compared with the consistent high expression in MGUS and healthy donors. MM patients in complete clinical remission displayed a higher percentage of CD27(+) PC compared with patients at diagnosis, relapse or in partial remission. In MM, loss of CD27 correlated with loss of CD19 (R (2) = 0.4, P
- Published
- 2003
10. Myeloma clonotypic B cells are hampered in their ability to undergo B-cell differentiation in vitro
- Author
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Guikema, JEJ, Vellenga, E, Bakkus, MHC, Bos, NA, Guided Treatment in Optimal Selected Cancer Patients (GUTS), Stem Cell Aging Leukemia and Lymphoma (SALL), and Translational Immunology Groningen (TRIGR)
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POLYMERASE-CHAIN-REACTION ,TRANSPLANTATION ,BONE-MARROW ,PROLIFERATION ,differentiation ,PERIPHERAL-BLOOD ,INTERLEUKIN-10 ,multiple myeloma ,MALIGNANT PLASMA-CELL ,MULTIPLE-MYELOMA ,IL-10 ,CD40 ,clonotypic B cell ,SEQUENCES REVEAL - Abstract
In the peripheral blood (PB) of multiple myeloma (MM) patients, clonotypic B cells are present that express the identical V( D) J rearrangements as the malignant plasma cells in the bone marrow. In the present study, the proliferative capacity of clonotypic B cells from MM patients (n = 10) and the ability to differentiate in vitro was determined using the CD40-culturing system. For six patients, the presence of clonotypic B cells expressing variant immunoglobulin (Ig) isotypes was assessed by Ig isotype-specific allele-specific oligonucleotide reverse transcription polymerase chain reaction (ASO-RT-PCR) after culturing with CD40L and interleukin 4 (IL-4). In three out of six patients, clonotypic B cells expressing variant isotypes were detected both before and after culturing. The ability of clonotypic B cells to undergo B-cell differentiation was studied by abrogating CD40 signalling accompanied by IL-10 and IL-2 stimulation, enhancing differentiation towards Ig-secreting cells. The numbers of clonotypic B cells were determined by quantitative ASO-PCR. An increase in cell number was observed upon CD40L and IL-4 stimulation, whereas the relative number of clonotypic B cells was unaltered. In contrast, upon B-cell differentiation the relative number of clonotypic B cells decreased. In conclusion, clonotypic B cells can be cultured and isolated in vitro using the CD40 system. Clonotypic B cells responded to CD40 triggering in a similar fashion as to non-clonotypic normal B cells. However, the ability of clonotypic B cells to undergo in vitro activation and differentiation into Ig-secreting cells is hampered.
- Published
- 2002
11. Gut colonization of mice with actA-negative mutant of Listeria monocytogenes can stimulate a humoral mucosal immune response
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Manohar, M, Baumann, DO, Bos, NA, Cebra, JJ, Cell Biochemistry, and Translational Immunology Groningen (TRIGR)
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IGA EXPRESSION ,PEYER PATCH ,INFECTION ,ANTIGEN ,T-CELLS ,CENTER B-CELLS ,PROTEIN ,HEMOLYSIN ,EPITHELIAL-CELLS ,INOCULATION - Abstract
We used Listeria monocytogenes, a gram-positive, facultative intracellular bacterium, to study the gut mucosal immune responses following oral infection. We employed a germfree (GF) mouse model to try to accentuate the development of a humoral mucosal immune response in the gut, and we used oral colonization with one of the mutants, actA-negative (Delta actA) L. monocytogenes, to restrict infection largely to the gut. The Delta actA mutant was able to colonize the intestinal mucosa of formerly GF mice for long periods of time without causing disease while eliciting secretory immunoglobulin A (IgA) responses, as evidenced by gut tissue fragment culture assays. Flow cytometric analyses and immunohistochemical methods showed the development of only minimal germinal center reactions (GCR) in Peyer's patches and more robust GCR in mesenteric lymph nodes. Pronounced increases in total (natural) IgA production occurred in gut tissues by day 7 and were maintained for up to 90 days. Levels of specific IgA were modest in gut tissues on day 14, increased until day 76, and stabilized at day 90. We also observed a significant rise in serum IgA and IgG1 levels following oral infection by listeriae, Upon colonization, the organisms mainly infected the intestines and intestinal lumen, and we only sporadically observed few colony-forming bacteria in the liver and spleen, We observed a marked rise in IgA-secreting cells, including listeria-specific IgA antibody-secreting cells, in the lamina propria of the small intestine by enzyme-linked immunospot assays. To ascertain whether some of the IgA was specific for listeriae, we performed Western blot analysis to test the reactivity of IgA from fragment cultures to antigens in sonicates of L. monocytogenes. We detected IgA binding to antigenic proteins with molecular masses of 96, 60, 40, and 14 kDa in the Listeria sonicates.
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- 2001
12. B-1 cells and the intestinal microflora
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Bos, NA, Cebra, JJ, Kroese, FGM, Potter, M, Melchers, F, Cell Biochemistry, and Translational Immunology Groningen (TRIGR)
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B-CELLS ,ANTIBODIES ,INFECTION ,FILAMENTOUS BACTERIA ,GUT ,ISOTYPES ,IGA PLASMA-CELLS ,DEFICIENT MICE - Published
- 2000
13. Multiple myeloma related cells in patients undergoing autologous peripheral blood stem cell transplantation
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Guikema, JEJ, Vellenga, E, Veeneman, JM, Hovenga, S, Bakkus, MHC, Klip, H, Bos, NA, Other departments, Faculteit Medische Wetenschappen/UMCG, Cell Biochemistry, Guided Treatment in Optimal Selected Cancer Patients (GUTS), Stem Cell Aging Leukemia and Lymphoma (SALL), and Translational Immunology Groningen (TRIGR)
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multiple myeloma ,MALIGNANT PLASMA-CELL ,REPERTOIRE ,autologous stem cell transplantation ,ASO-RT-PCR ,BONE-MARROW TRANSPLANTATION ,myeloma clonally related cells - Abstract
A high incidence of oligoclonal serum M-components is observed in multiple myeloma (MM) patients treated with autologous Stem cell transplantation (ASCT). To determine whether these hi-components are produced by myeloma clonally related cells or caused by an aberrant B-cell regeneration we analysed by semi-nested ASO-RT-PCR and DNA sequencing the immunoglobulin (Ig) variable genes (VH) obtained from bone marrow samples obtained before and after transplantation and peripheral blood stern cell (PBSC) samples from seven patients. Myeloma clonally related cells are identifiable by the expression of variant Ig heavy chain isotypes and were detected in two patients at presentation. No myeloma clonally related cells were found in post-transplantation samples (n = 7) in spite of the appearance of new serum M-components, However, in two cases we amplified sequences from post-transplantation bone marrow cells that were able to bind to the B-cell clone-specific CDR3 oligonucleotides but showed no further similarity regarding the VDT rearrangement, These data indicate that serum oligoclonality posttransplantation is not caused by myeloma clonally related B cells but rather by the regenerating B-cell compartment.
- Published
- 1999
14. Monoclonal gammopathies in aging mu,x-transgenic mice: involvement of the B-1 cell lineage
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vanArkel, C, Hopstaken, CM, Zurcher, C, Bos, NA, Kroese, FGM, Savelkoul, HFJ, Benner, R, Radl, J, Cell Biochemistry, and Translational Immunology Groningen (TRIGR)
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EXPRESSION ,ACTIVATION ,DOWN-REGULATION ,TRANSGENIC MOUSE LINE ,IGM ,monoclonal immunoglobulin ,B-CELLS ,aging ,IMMUNOGLOBULIN ,AUTOIMMUNE ,mu,kappa-transgenic mouse ,B cell lineage ,ISOTYPE EXCLUSION - Abstract
Monoclonal gammopathies (MG) are monoclonal proliferative disorders of B cells at the differentiation stage of Ig production. They can be detected in the serum, either as transient or as persistent homogenous immunoglobulin (H-Ig) components. The exact phenotype, localization, and cell lineage origin of the precursor tells of MG are unknown, but may be crucial for both the correct diagnosis and for timely efficient treatment of the malignant forms. We used for the first time transgenic (Tg) mice (Sp6: mu/chi) to study the origin of MG, In the mu, chi Tg mice a small proportion of B cells can still produce endogenous IgM. These cells are of B-1 cell origin. The MG in Tg mice showed a later onset and a lower frequency than those in littermate control mice, mainly due to a four times lower frequency of benign monoclonal gammopathy. The 10% of B-1 cells that were able to produce endogenous Ig led to the development of MG in a frequency that was half the number of MG found in normal littermates. None of the MG in Tg mice produced an Ig of the Tg origin and therefore it can be concluded that they originated from B-1 cells.
- Published
- 1997
15. Offspring of xenogeneically-reconstituted scid scid mice are capable of a primary xenogeneic immune response to DNP-KLH
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Greenwood, JD, Bos, NA, Croy, BA, Cell Biochemistry, and Translational Immunology Groningen (TRIGR)
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MONONUCLEAR-CELLS ,dinitrophenyl-keyhole limpet hemocyanin ,xenogeneic PBL reconstitution ,hemic and immune systems ,chemical and pharmacologic phenomena ,LYMPHOMAGENESIS ,SCID ,LYMPHOCYTES ,SEVERE COMBINED IMMUNODEFICIENCY ,IMMUNIZATION ,LEUKOCYTES ,PBL-SCID-bo ,ENGRAFTMENT ,ANTIBODIES ,primary immune response ,HUMAN PERIPHERAL-BLOOD ,SYSTEM - Abstract
Human peripheral blood leukocyte (PBL) reconstitution of severe combined immunodeficient (SCID) mice has provided a small animal model system (hu-PBL-SCID) useful for the study of the human immune system and disease pathogenesis. Transfer of xenogeneic PBL from donors other than humans has also been successful; however, the controversy remains regarding the capability of xenogeneically engrafted lymphocytes to mount a primary immune response. Human cells have been identified in offspring from hu-PBL-SCID but were not evaluated for a primary immune response, In the present study, offspring of bovine PBL-reconstituted SCID mice (F1-PBL-SCID-bo) were assessed for specific immune function, Sera from all of the F1-PBL-SCID-bo contained relatively low levels of bovine IgG 5 weeks after birth but bovine Ig became undetectable by 14 or 18 weeks. Eight F1-PBL-SCID-bo (23 or 27 weeks of age) were immunized with a single dose of 100 mu g dinitrophenyl-keyhole limpet hemocyanin (DNP-KLH). Individual cells secreting bovine antibody were enumerated using the ELISA-plaque assay. One week after immunization, bovine cells secreting bovine immunoglobulin (IgG) specific for DNP-KLH were identified in the spleens from three of the F1-PBL-SCID-bo at a frequency of one antibody-secreting cell per 9x10(3) to 1x10(6) spleen cells. Thus, xenogeneic lymphocytes, passed from the mother to her offspring, retain the capacity for a primary immune response to DNP-KLH.
- Published
- 1996
16. MEASUREMENT OF AFFINITY IN SERUM SAMPLES OF ANTIGEN-FREE, GERM-FREE AND CONVENTIONAL MICE AFTER HYPERIMMUNIZATION WITH 2,4-DINITROPHENYL KEYHOLE LIMPET HEMOCYANIN, USING SURFACE-PLASMON RESONANCE
- Author
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BAKKER, R, LASONDER, E, BOS, NA, Cell Biochemistry, and Translational Immunology Groningen (TRIGR)
- Subjects
BIACORE ,FREE DIET ,SPECIFICITIES ,IMMUNIZATION ,GERM-FREE MICE ,MATURATION ,REPERTOIRE ,ANTIGEN-FREE MICE ,HYPERIMMUNIZATION ,B-CELLS ,ANTIBODIES ,T-CELLS ,IMMUNE-RESPONSE ,BALB/C MICE ,AFFINITY - Abstract
We previously investigated the primary and secondary responses and hyperimmunization to the T cell-dependent antigen 2,4-dinitrophenyl keyhole limpet hemocyanin (DNP-KLH) in antigen-free (AF), germ-free (GF) and conventional (CV) mice. Both the absolute and relative numbers of DNP-specific IgG-secreting cells in the spleen of AF mice were considerably higher compared to GF and CV mice, especially after hyperimmunization. In the present study we measured the total and DNP-specific IgG concentration in the sera of these hyperimmunized mice using a sensitive sandwich enzyme-linked immunosorbent assay. With respect to the total IgG concentration before and after hyperimmunization, the AF mice showed an almost 13-fold increase after boosting with the antigen; the GF mice showed an approximately 8-fold increase. A slight but non-significant increase was observed in the CV mice. The total as well as the DNP-specific IgG levels in the AF-immunized mice were 2-fold and 5-fold higher compared to GF and CV mice, respectively. With the use of Surface Plasmon Resonance instrumentation (BIAcore(TM), Pharmacia, Uppsala, Sweden) we obtained mean binding affinities (K-A) of the polyclonal samples of the three groups of hyperimmunized mice. IgA and IgM samples displayed low affinity for DNP-lysine. The AF mice displayed the highest K-A value among IgG antibodies, followed by GF mice, while CV mice showed a 3-fold lower K-A compared to AF mice. These differences were mainly determined by the dissociation rate constant (k(diss)), since no significant changes were observed in the association rate constant (k(ass)). Furthermore, the sera of the CV mice have a lower percentage of high-affinity antibodies compared to GF and AF mice. These results suggest that besides a higher overall binding affinity seen in AF mice, and to a lesser extent in GF mice, the relative contribution of high-affinity IgG is greater in AF mice compared to CV mice.
- Published
- 1995
17. SPLEEN-CELLS FROM ANTIGEN-MINIMIZED MICE ARE SUPERIOR TO SPLEEN-CELLS FROM GERM-FREE AND CONVENTIONAL MICE IN THE STIMULATION OF PRIMARY IN-VITRO PROLIFERATIVE RESPONSES TO NOMINAL ANTIGENS
- Author
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HOOPER, DC, MOLOWITZ, EH, BOS, NA, PLOPLIS, VA, CEBRA, JJ, University of Groningen, and Translational Immunology Groningen (TRIGR)
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EXPRESSION ,PRIMARY RESPONSE ,MONOCLONAL-ANTIBODY ,PRESENTING CELLS ,FREE DIET ,MEMORY ,ANTIGEN-PRESENTING CELLS ,AUTOLOGOUS ERYTHROCYTES ,ANTIGEN-FREE MICE ,B-CELLS ,IMMUNOGLOBULIN ,CD4 T CELLS ,CD4+ T-CELLS ,NEONATAL BALB/C MICE - Abstract
T lymphocytes from mice reared under conditions of differential exposure to food, environmental and microbial antigens were compared for phenotypic shifts that may be associated with prior exposure to antigens as well as functional variations in the ability to respond to antigens ne novo. While the intra-epithelial CD8 T cell compartment was found to differ significantly in the type of T cell receptor predominantly expressed, CD4 T cells from various lymphoid organs of conventionally reared specific pathogen-free (CL-SPF) mice showed only subtle phenotypic differences from cells obtained from antigen-minimized germ-free (AF) and germ-free (GF) mice. Cells derived from mice exposed to a reduced antigen load exhibited primary in vitro proliferative responses to antigens such as dinitrophenyl-keyhole limpet hemocyanin which were significantly enhanced when compared with similar responses of cells from conventional mice. In cell mixing experiments, differences in the reactivity of T cells from the spleens of AF, GF and CL-SPF mice were dependent on the source of the spleen cells employed as antigen-presenting cells (APC). Experiments in which the T cell population was held constant revealed that, as APC, spleen cells from AF mice were most often superior to spleen cells from GF mice which were in turn considerably better than a similar population from SPF mice. We conclude that the enhanced primary reactivity of spleen cells from AF mice to nominal antigen in vitro is likely to be the result of a difference in the function and/or regulatory activities of the cell population employed as APC in this investigation.
- Published
- 1995
18. MRC OX19 RECOGNIZES THE RAT CD5 SURFACE GLYCOPROTEIN, BUT DOES NOT PROVIDE EVIDENCE FOR A POPULATION OF CD5(BRIGHT) B-CELLS
- Author
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VERMEER, LA, DEBOER, NK, BUCCI, C, BOS, NA, KROESE, FGM, ALBERTI, S, University of Groningen, and Translational Immunology Groningen (TRIGR)
- Subjects
ANTIGEN ,MEMBRANE GLYCOPROTEIN ,chemical and pharmacologic phenomena ,hemic and immune systems ,LINEAGE ,LEU-1 ,MOUSE LYMPHOCYTES-T ,CD5 ,VH GENE ,PHOSPHATIDYL CHOLINE ,ANTIBODY ,immune system diseases ,hemic and lymphatic diseases ,RAT ,SUBPOPULATIONS ,MRC OX19 ,LY-1 B - Abstract
To clone the rat CD5 gene we first produced two rat CD5 probes. The probes were obtained by polymerase chain reaction (PCR) on rat genomic DNA using primers designed on conserved regions between mouse and human CD5. The screening of a rat cDNA library at high stringency using these probes resulted in a 1.5-kb positive clone. The DNA sequence of this clone confirmed its CD5 nature, but the clone appeared to lack part of the 5' and part of the 3' end. These missing 5' and 3' ends were obtained by PCR on rat thymus RNA. By ligating these PCR products to the original 1.5-kb CDM8 clone, a full-length rat CD5 gene was constructed. The full-length clone showed high identity with mouse and human CD5; however, at the 5' site of the gene a region of 36 nucleotides is present which is not seen in either mouse or human CD5. We have evidence that this sequence is a normal constituent of the rat CD5 gene: first, it is in frame with the rest of the CD5 coding sequence; second, it does not contain a stop codon; and third, it is also present in the CD5 gene of other rat strains. We transfected the full-length CD5 construct in COS cells and demonstrated that indeed the CD5 protein is recognized by MRC OX19. Although we showed that CD5 mRNA is present in rat B cells, extensive flow cytometry analysis using MRC OX19 as antibody failed to detect B cells expressing significant levels of CD5 on their cell surface compared to other B cells in any tissue or cell suspension tested from a variety of rat strains. This is in contrast with the mouse where a distinct population of B cells (B-1a cells) can be found expressing more CD5 than the other B cells. Either B-1 cells are not present in rats or CD5 is not the right phenotypic marker for rat B-1 cells. It still remains to be investigated whether a population of B cells with functions similar to those of murine B-1 cells is present in rats.
- Published
- 1994
19. HUMORAL IMMUNE-RESPONSE TO 2,4-DINITROPHENYL KEYHOLE LIMPET HEMOCYANIN IN ANTIGEN-FREE, GERM-FREE AND CONVENTIONAL BALB/C MICE
- Author
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BOS, NA, PLOPLIS, VA, University of Groningen, and Translational Immunology Groningen (TRIGR)
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STIMULATION ,EXPRESSION ,B-CELL REPERTOIRE ,FREE DIET ,chemical and pharmacologic phenomena ,GERM-FREE ,GENE ,ACTIVATION ,ANTIBODY ,IMMUNE RESPONSE ,T-CELLS ,ANTIBODY FORMATION ,ANTIGEN-FREE ,SPECIFICITY ,GENERATION - Abstract
The B cell immune response to 2,4-dinitrophenyl (DNP) keyhole limpet hemocyanin was compared in antigen-free, germ-free and conventional BALB/c mice. The numbers of total and of DNP-specific IgM-, IgG- and IgA-secreting cells in the spleen were determined by enzyme-linked immunosorbent plaque assays after primary, secondary and hyperimmunization. Three days after primary immunization a peak of DNP-specific IgM-secreting cells was seen in conventional mice only. However, this specific response was accompanied by a rise in the total number of IgM-secreting cells. At day 6 after primary immunization the total number and the frequency of DNP-specific IgG-secreting cells were higher in antigen-free mice, compared to germ-free and conventional mice. After secondary immunization in conventional mice only, a considerable bystander IgG response was seen together with the DNP-specific IgG response. At the end of the secondary response 90% of all IgG-secreting cells were DNP specific in antigen-free mice, while the corresponding figure in germ-free and conventional mice was 63% and 14%, respectively. After hyperimmunization, the absolute number of DNP-specific IgG-secreting cells in the spleen was 5-fold and 11-fold higher in antigen-free mice then in germ-free and conventional mice, respectively. Approximately 48% of all IgG-secreting cells were DNP specific in antigen-free mice,while the corresponding figure in germ-free and conventional mice was 17% and 12%, respectively. The results show that the exogenous antigenic load of animals influences the immune response to newly introduced antigens. The higher absolute and relative numbers of antigen-specific IgG-secreting cells after hyperimmunization in antigen-free mice compared to germ-free and conventional mice may provide a better source for antigen-specific B cells that eventually can be used for hybridoma production.
- Published
- 1994
20. Analysis of IgA-producing hybridomas derived from peritoneal B1 cells
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BOS, NA, BUN, JCAM, BIJMA, H, CEBRA, ER, CEBRA, JJ, DEENEN, GJ, VANDERCAMMEN, MJF, KROESE, FGM, Heinen, E, Defresne, MP, Boniver, J, Geenen, Cell Biochemistry, and Translational Immunology Groningen (TRIGR)
- Published
- 1994
21. B562 Increasing Numbers of Most Mature Peripheral Blood B-Subsets are Observed in Monoclonal Gammopathies
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Perez-Andres, M, primary, Paiva, B, additional, Schmitz, A, additional, Fuhler, G, additional, Van Duin, M, additional, Almeida, J, additional, Sonneveld, P, additional, Bos, NA, additional, Johnsen, HE, additional, San Miguel, J, additional, and Orfao, A, additional
- Published
- 2009
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22. Immortalization of b-cells from patients with benign monoclonal gammopathy
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BOS, NA, van Straaten, JFM, van Imhoff, GW, de Jong, HJ, Marrink, J, RADL, J, VANCAMP, B, and Translational Immunology Groningen (TRIGR)
- Published
- 1991
23. RENEWAL RATE OF B-CELLS IN GERM-FREE BALB/C MICE FED A CHEMICALLY DEFINED DIET
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BOS, NA, PLEASANTS, [No Value], WOSTMANN, BS, FREITAS, AA, BENNER, R, HEIDT, PJ, VOSSEN, JM, RUSCH, VC, University of Groningen, and Translational Immunology Groningen (TRIGR)
- Published
- 1990
24. Persistence of immunoglobulin-producing cells in parotid salivary glands of patients with primary Sjogren's syndrome after B cell depletion therapy.
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Hamza N, Bootsma H, Yuvaraj S, Spijkervet FK, Haacke EA, Pollard RP, Visser A, Vissink A, Kallenberg CG, Kroese FG, and Bos NA
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- 2012
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25. New prebiotic blend of polydextrose and galacto-oligosaccharides has a bifidogenic effect in young infants.
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Scalabrin DM, Mitmesser SH, Welling GW, Harris CL, Marunycz JD, Walker DC, Bos NA, Tölkkö S, Salminen S, Vanderhoof JA, Scalabrin, Deolinda M F, Mitmesser, Susan H, Welling, Gjalt W, Harris, Cheryl L, Marunycz, John D, Walker, D Carey, Bos, Nico A, Tölkkö, Satu, Salminen, Seppo, and Vanderhoof, Jon A
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- 2012
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26. B552 The European Myeloma Stem Cell Network (MSCNET)
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Johnsen, HE, Schmitz, A, Fogd, KB, Andersen, H, Vanderkerken, K, Valckenborgh, K, Sonneveld, EV, Duin, MV, Orfao, A, Hernandez-Campo, Sanz, RG, Paiva, B, Sahota, S, Pietras, DJ, Weston-Bell, N, Babbage, G, Bos, NA, Fuhler, G, Klein, B, Caraux, A, Hose, D, Seckinger, A, Niklas, Z, Pfeifer, S, Schreder, M, Andres, MP, San Miguel, J, Almeida, J, Hoejfeldt, A, Hansen, AL, Dybkaer, K, Bøgsted, M, Urup, T, and Pilgaard, L
- Published
- 2009
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27. Regulation of the intestinal microbiota by Paneth cell defensins
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Salzman, NH, Bos, NA, Harmsen, HJ, Welling, GW, Paterson, Y, and Bevins, CL
28. The consumer quality index (CQ-index) in an accident and emergency department: development and first evaluation
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Bos Nanne, Sturms Leontien M, Schrijvers Augustinus JP, and van Stel Henk F
- Subjects
Factor analysis, statistical ,Emergency medical services ,Patient experiences ,Patient satisfaction, statistics and numerical data ,Questionnaires, standards ,Health care surveys ,Public aspects of medicine ,RA1-1270 - Abstract
Abstract Background Assessment of patients’ views are essential to provide a patient-centred health service and to evaluating quality of care. As no standardized and validated system for measuring patients’ experiences in accident and emergency departments existed, we have developed the Consumer Quality index for the accident and emergency department (CQI A&E). Methods Qualitative research has been undertaken to determine the content validity of the CQI A&E. In order to assess psychometric characteristics an 84-item questionnaire was sent to 653 patients who had attended a large A&E in the Netherlands. Also, fifty importance questions were added to determine relevance of the questions and for future calculations of improvement scores. Exploratory factor analysis was applied to detect the domains of the questionnaire. Results Survey data of 304 (47%) patients were used for the analysis. The first exploratory factor analysis resulted in three domains based on 13 items: ‘Attitude of the healthcare professionals’, ‘Environment and impression of the A&E’ and ‘Respect for and explanation to the patient’. The first two had an acceptable internal consistency. The second analysis, included 24 items grouped into 5 domains: ‘Attitude of the healthcare professionals’, ‘Information and explanation’, ‘Environment of the A&E’,’Leaving the A&E’ and ‘General information and rapidity of care’. All factors were internal consistent. According to the patients, the three most important aspects in healthcare performance in the A&E were: trust in the competence of the healthcare professionals, hygiene in the A&E and patients’ health care expectations. In general, the highest improvement scores concerned patient information. Conclusions The Consumer Quality index for the accident and emergency department measures patients’ experiences of A&E healthcare performance. Preliminary psychometric characteristics are sufficient to justify further research into reliability and validity.
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- 2012
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29. Large head metal-on-metal cementless total hip arthroplasty versus 28mm metal-on-polyethylene cementless total hip arthroplasty: design of a randomized controlled trial
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van Raaij Jos JAM, Bos Nanne, and Zijlstra Wierd P
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Diseases of the musculoskeletal system ,RC925-935 - Abstract
Abstract Background Osteoarthritis of the hip is successfully treated by total hip arthroplasty with metal-on-polyethylene articulation. Polyethylene wear debris can however lead to osteolysis, aseptic loosening and failure of the implant. Large head metal-on-metal total hip arthroplasty may overcome polyethylene wear induced prosthetic failure, but can increase systemic cobalt and chromium ion concentrations. The objective of this study is to compare two cementless total hip arthroplasties: a conventional 28 mm metal-on-polyethylene articulation and a large head metal-on-metal articulation. We hypothesize that the latter arthroplasties show less bone density loss and higher serum metal ion concentrations. We expect equal functional scores, greater range of motion, fewer dislocations, fewer periprosthetic radiolucencies and increased prosthetic survival with the metal-on-metal articulation. Methods A randomized controlled trial will be conducted. Patients to be included suffer from non-inflammatory degenerative joint disease of the hip, are aged between 18 and 80 and are admitted for primary cementless unilateral total hip arthroplasty. Patients in the metal-on-metal group will receive a cementless titanium alloy acetabular component with a cobalt-chromium liner and a cobalt-chromium femoral head varying from 38 to 60 mm. Patients in the metal-on-polyethylene group will receive a cementless titanium alloy acetabular component with a polyethylene liner and a 28 mm cobalt-chromium femoral head. We will assess acetabular bone mineral density by dual energy x-ray absorptiometry (DEXA), serum ion concentrations of cobalt, chromium and titanium, self reported functional status (Oxford hip score), physician reported functional status and range of motion (Harris hip score), number of dislocations and prosthetic survival. Measurements will take place preoperatively, perioperatively, and postoperatively (6 weeks, 1 year, 5 years and 10 years). Discussion Superior results of large head metal-on-metal total hip arthroplasty over conventional hip arthroplasty have been put forward by experts, case series and the industry, but to our knowledge there is no randomized controlled evidence. Conclusion This randomized controlled study has been designed to test whether large head metal-on-metal cementless total hip arthroplasty leads to less periprosthetic bone density loss and higher serum metal ion concentrations compared to 28 mm metal-on-polyethylene cementless total hip arthroplasty. Trial registration Netherlands Trial Registry NTR1399
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- 2008
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30. Circulating B cells display differential immune regulatory molecule expression in granulomatosis with polyangiitis.
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Bonasia CG, Inrueangsri N, Bijma T, Borggrewe M, Post AI, Mennega KP, Abdulahad WH, Rutgers A, Bos NA, and Heeringa P
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- Humans, Male, Middle Aged, Female, Aged, Adult, B7-2 Antigen metabolism, B-Lymphocyte Subsets immunology, B-Lymphocyte Subsets metabolism, B-Lymphocytes immunology, Receptors, Complement 3d, Receptors, IgG metabolism, Receptors, IgG immunology, Cross-Sectional Studies, Flow Cytometry, Granulomatosis with Polyangiitis immunology
- Abstract
Granulomatosis with polyangiitis (GPA) is a B-cell-mediated, relapsing, autoimmune disease. There is a need for novel therapeutic approaches and relapse markers to achieve durable remission. B cells express immune regulatory molecules that modulate their activation and maintain tolerance. While recent studies show dysregulation of these molecules in other autoimmune diseases, data on their expression in GPA are limited. This study aimed to map the expression of surface immune regulatory molecules on circulating B-cell subsets in GPA and correlate their expression with clinical parameters. Immune regulatory molecule expression on circulating B-cell subsets was comprehensively examined in active GPA (n = 16), GPA in remission (n = 16), and healthy controls (n = 16) cross-sectionally using a 35-color B-cell-specific spectral flow cytometry panel. Our supervised and unsupervised in-depth analysis revealed differential expression of inhibitory and stimulatory immune molecules on distinct B-cell populations in GPA, with the most notable differences observed in active GPA. These differences include the upregulation of FcγRIIB on nonmature B cells, downregulation of CD21 and upregulation of CD86 on antigen-experienced B cells, and elevated CD22 expression on various populations. Additionally, we found a strong association between FcγRIIB, BTLA, and CD21 expression on specific B-cell populations and disease activity in GPA. Together, these findings provide novel insights into the immune regulatory molecule expression profile of B cells in GPA and could potentially form the foundation for new therapeutic approaches and disease monitoring markers., (© The Author(s) 2024. Published by Oxford University Press on behalf of the British Society for Immunology.)
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- 2025
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31. Gene expression profiling in PBMCs for acute rejection in lung transplant recipients reveals myeloid responses.
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Liu S, Westra J, Hu S, Verschuuren EAM, van Kempen LC, van Baarle D, and Bos NA
- Abstract
The acute rejection (AR) diagnosis depends on transbronchial biopsy, which is semi-invasive and not easily performed . Our study used the Nanostring gene expression technology on PBMCs obtained from lung transplant recipients (LTRs) to search for biomarkers. We identified distinct differential gene profiles between patients with stable status (STA) and AR. Subsequently, we independently evaluated monocyte compositions in PBMCs using flow cytometry and assessed the levels of 7 chemokines in serum using Luminex. The 48 top differentially expressed genes (DEGs) were identified, utilizing a criterion of at least a 1.5-fold change between two groups, with a false discovery rate (FDR) p -Adj < 0.05. Of these 48 genes, the top 10 genes with the highest fold changes and significant p -values were selected for qPCR validation. CD68, ANXA1, ITGB, and IFI30 can be confirmed among the validated genes. A significantly lower percentage of CD14 + CD16- classical monocytes was observed in AR than in STA patients, which aligns with downregulated DEGs. Many of the DEGs were related to monocytes-macrophages and chemokines. Although these results still need to be confirmed in larger cohorts, they suggest that gene profiling of PBMC can help to identify markers related to AR in LTRs., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2024 Liu, Westra, Hu, Verschuuren, van Kempen, van Baarle and Bos.)
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- 2024
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32. Circulating immune profile in granulomatosis with polyangiitis reveals distinct patterns related to disease activity.
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Bonasia CG, Inrueangsri N, Bijma T, Mennega KP, Wilbrink R, Arends S, Abdulahad WH, Bos NA, Rutgers A, and Heeringa P
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- Humans, Male, Female, Middle Aged, Aged, Adult, Monocytes immunology, Monocytes metabolism, Leukocytes, Mononuclear immunology, Leukocytes, Mononuclear metabolism, Immunophenotyping, Biomarkers blood, Granulomatosis with Polyangiitis immunology, Granulomatosis with Polyangiitis blood, Granulomatosis with Polyangiitis diagnosis, Cytokines blood, Cytokines metabolism
- Abstract
Granulomatosis with polyangiitis (GPA) is an autoimmune disorder characterized by recurrent relapses that can cause severe tissue damage and life-threatening organ dysfunction. Multiple immune cells and cytokines/chemokines are involved in the different stages of the disease. Immune profiling of patients may be useful for tracking disease activity, however, reliable immune signatures for GPA activity are lacking. In this study, we examined circulating immune profiles in GPA patients during active and remission disease states to identify potential immune patterns associated with disease activity. The distribution and phenotypic characteristics of major circulating immune cells, and the profiles of circulating cytokines/chemokines, were studied on cryopreserved peripheral blood mononuclear cells from GPA patients (active, n = 20; remission, n = 20) and healthy controls (n = 20) leveraging a 40-color optimized multicolor immunofluorescence panel (OMIP-69) and in serum using a 46-plex Luminex multiplex assay, respectively. Deep phenotyping uncovered a distinct composition of major circulating immune cells in active GPA and GPA in remission, with the most significant findings emerging within the monocyte compartment. Our detailed analysis revealed circulating monocyte diversity beyond the conventional monocyte subsets. We identified eight classical monocyte populations, two intermediate monocyte populations, and one non-classical monocyte population. Notably, active GPA had a higher frequency of CD45RA
+ CCR5+ CCR6- CCR7+/low CD127- HLA-DR+ CD2- classical monocytes and a lower frequency of CD45RA- CCR5-/low CCR6- CCR7- CD127- HLA-DR+ CD2+/- classical monocytes, which both strongly correlated with disease activity. Furthermore, serum levels of CXCL1, CXCL2, and CCL20, all linked to monocyte biology, were elevated in active GPA and correlated strongly with disease activity. These findings shed light on the circulating immune profile of GPA and may lead to immune signature profiles for assessing disease activity. Monocytes in particular may be studied further as potential markers for monitoring GPA., Competing Interests: Declaration of competing interest The authors have no conflicts of interest to disclose., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)- Published
- 2024
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33. Student engagement and learning outcomes: an empirical study applying a four-dimensional framework.
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Xu X, Shi Z, Bos NA, and Wu H
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- Humans, Learning, Curriculum, China, Students, Medical, Education, Medical
- Abstract
Introduction: This study applies Reeve's four-dimensional student engagement framework to a medical education context to elucidate the relationship between behavioral, emotional, cognitive, and agentic engagement and learning outcomes. Meanwhile, we categorize learning outcomes in knowledge and skills, and added taxonomies to the cognitive education objectives for the knowledge part, including memorization, comprehension, and application., Methods: We used the China Medical Student Survey to investigate student engagement, and combined it with the Clinical Medicine Proficiency Test for Medical Schools results as a standardized measurement of learning outcomes. We performed multivariate regression analyses to delve into the effectiveness of different types of student engagement. Moreover, we evaluated the moderating roles of gender and the National College Entrance Examination (NCEE) within the relationships between student engagement and learning outcomes., Results: We observed that emotional engagement is most effective in promoting learning outcomes in basic medical knowledge and basic clinical skills. Emotional engagement and cognitive engagement could effectively contribute to learning outcomes in all three aspects of basic medical knowledge. In contrast, behavioral and agentic engagement showed negative effects on learning outcomes. Besides, we found that the results of the NCEE played a positive moderating role., Conclusion: This study provides robust evidence for the effectiveness of emotional engagement and cognitive engagement in promoting learning outcomes. Whereas behavioral and agentic engagement may not be good predictors of learning outcomes in macro-level general competence tests. We suggest a combined effort by students and institutions to promote student engagement and bridge the distance between general competency tests and daily learning activities.
- Published
- 2023
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34. A social network perspective on peer relationship formation of medical undergraduates within large-scale learning communities.
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Zhou Y, Bos NA, Diemers AD, and Brouwer J
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- Humans, Learning, Peer Group, Social Networking, Students, Medical, Education, Medical methods, Education, Medical, Undergraduate
- Abstract
Introduction: Students' formal networks, which are formed by a formal curriculum design, such as formally organized study groups within learning communities (LCs), may benefit students' interactions and learning. It is unclear how large-scale LCs contribute to the formation of different informal peer relationships, which refers to student self-organized out-of-class relationships. Two mechanisms can explain relationship formation in LCs. Propinquity within formal networks and homophily of students' characteristics (nationality, sex, academic performance) may promote students' peer relationships. This study explores to what extent the formation of students' informal networks was determined by their formal networks (LCs) while controlling for students' characteristics and which mechanisms play an important role., Methods: With online surveys, data were collected about five informal networks (help-seeking, collaboration, information sharing, friendship, and learn-from) from 69 first- and 51 second- bachelor year medical students (2890 relationships). Students were divided into four LCs in the formal curriculum. We compared students' five informal network structures between first- and second-year students, domestic and international students, within and between formal networks. Besides, we used Quadratic Assignment Procedure (QAP) Regression Analysis in Ucinet to investigate the associations between students' informal and formal networks (LCs) and students' characteristics., Results: Propinquity (in the same LC) plays a role since students have more informal connections within LCs than between LCs. Furthermore, it seems to play a greater role for second-year students than for first-year students. Homophily of nationality is important in informal networking since students are more likely to connect with others of similar nationalities., Conclusion: Students become more connected within the LC when they remain in the same LC for a longer period. Formal networks enhance the students' informal interactions within LCs but seem to restrict the interactions among students from other LCs. International students need support in order to integrate with domestic students in LCs.
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- 2023
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35. Development and evaluation of the Measure of the International Learning Environment Status (MILES) in international higher education.
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Xu X, Schönrock-Adema J, and Bos NA
- Subjects
- Humans, Consensus, Culture, Internationality, Learning, Students
- Abstract
The aim of this study was to develop and evaluate an instrument to assess international students' perceptions of the international learning environment called 'Measure of the International Learning Environment Status' (MILES). We based the development of the MILES on a solid theoretical framework from Moos by addressing three domains to measure the quality of the international learning environment, namely goal direction, relationships, and system change and system maintenance. We have designed and constructed the instrument in three steps. Firstly, we have collected items from relevant existing instruments and grouped them into the three domains via content analysis. Secondly, we applied a Delphi procedure involving international higher education experts from different stakeholder groups and from different cultural backgrounds to identify and reach consensus on the items comprehensively covering important elements of the international learning environment. Thirdly, we carried out an initial questionnaire evaluation. The final MILES consisted of 47 items with 13 in the first domain, 17 in the second and 17 in the third domain. The content of the domains was clearly in line with Moos theoretical framework and we interpreted the sets of items as goal direction, relationships, and supporting services, respectively. This study provides a comprehensive and systematically developed instrument for future research to better understand international students' perspectives towards the international learning environment that are supported by stakeholders from a range of cultures., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Xu et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)
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- 2023
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36. Influence of online collaborative learning on social network and academic performance of medical students: lessons learned from the COVID-19 pandemic.
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Zhou Y, Xu X, Schönrock-Adema J, Brouwer J, Bos NA, and Diemers AD
- Abstract
Introduction: The social distancing restrictions due to the COVID-19 pandemic have changed students' learning environment and limited their social interactions. Therefore, the objective of this study was to investigate the influence of the social distancing restrictions on students' social networks, wellbeing, and academic performance., Methods: We performed a questionnaire study in which 102 students participated before and 167 students during the pandemic. They completed an online questionnaire about how they formed their five peer social networks (study-related support, collaboration, friendship, share information, and learn-from) out-of-class. We performed social network analysis to compare the sizes, structures, and compositions of students' five social networks before and during the pandemic, between first- and second-year students, and between international and domestic students. Additionally, we performed Kruskal-Wallis H test to compare students' academic performance before and during the pandemic. We performed thematic analysis to answers for two open-end questions in the online questionnaire to explore what difficulties students encountered during the COVID-19 pandemic and what support they needed., Results: The results showed that the size of students' social networks during the pandemic was significantly smaller than before the pandemic. Besides, the formation of social networks differed between first- and second-year students, and between domestic and international students. However, academic performance did not decline during the COVID-19 pandemic. Furthermore, we identified three key areas in which students experienced difficulties and needed support by thematic analysis: social connections and interactions, learning and studying, and physical and mental wellbeing., Conclusion: When institutions implement learning with social distancing, such as online learning, they need to consider changes in students' social networks and provide appropriate support., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Zhou, Xu, Schönrock-Adema, Brouwer, Bos and Diemers.)
- Published
- 2023
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37. Differences in IgG autoantibody Fab glycosylation across autoimmune diseases.
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Koers J, Sciarrillo R, Derksen NIL, Vletter EM, Fillié-Grijpma YE, Raveling-Eelsing E, Graça NAG, Leijser T, Pas HH, Laura van Nijen-Vos L, Braham MVJ, Buisman AM, de Jong J, Schriek AI, Tio-Gillen AP, Teng YKO, Steenhuis M, Swaneveld FH, de Taeye SW, van Gils MJ, Verschuuren JJGM, Rutgers B, Heeringa P, Horváth B, Jacobs BC, de Leeuw K, Franssen CFM, Veyradier A, Coppo P, Gelderman KA, Marieke van Ham S, van Els CACM, van der Woude D, Huizinga R, Huijbers MG, Kuijpers TW, Toes REM, Bos NA, and Rispens T
- Subjects
- Humans, Autoantibodies, Immunoglobulin G, Autoantigens, Autoimmune Diseases, Myasthenia Gravis, Arthritis, Rheumatoid, Lupus Erythematosus, Systemic
- Abstract
Background: Increased prevalence of autoantibody Fab glycosylation has been demonstrated for several autoimmune diseases., Objectives: To study whether elevated Fab glycosylation is a common feature of autoimmunity, this study investigated Fab glycosylation levels on serum IgG and its subclasses for autoantibodies associated with a range of different B cell-mediated autoimmune diseases, including rheumatoid arthritis, myasthenia gravis subtypes, pemphigus vulgaris, antineutrophil cytoplasmic antibody-associated vasculitis, systemic lupus erythematosus, anti-glomerular basement membrane glomerulonephritis, thrombotic thrombocytopenic purpura, and Guillain-Barré syndrome., Methods: The level of Fab glycosylated IgG antibodies was assessed by lectin affinity chromatography and autoantigen-specific immunoassays., Results: In 6 of 10 autoantibody responses, in 5 of 8 diseases, the investigators found increased levels of Fab glycosylation on IgG autoantibodies that varied from 86% in rheumatoid arthritis to 26% in systemic lupus erythematosus. Elevated autoantibody Fab glycosylation was not restricted to IgG
4 , which is known to be prone to Fab glycosylation, but was also present in IgG1 . When autoimmune diseases with a chronic disease course were compared with more acute autoimmune illnesses, increased Fab glycosylation was restricted to the chronic diseases. As a proxy for chronic autoantigen exposure, the investigators determined Fab glycosylation levels on antibodies to common latent herpes viruses, as well as to glycoprotein 120 in individuals who are chronically HIV-1-infected. Immunity to these viral antigens was not associated with increased Fab glycosylation levels, indicating that chronic antigen-stimulation as such does not lead to increased Fab glycosylation levels., Conclusions: These data indicate that in chronic but not acute B cell-mediated autoimmune diseases, disease-specific autoantibodies are enriched for Fab glycans., (Copyright © 2023 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)- Published
- 2023
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38. Challenges to acquire similar learning outcomes across four parallel thematic learning communities in a medical undergraduate curriculum.
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Zhou Y, Wieringa TH, Brouwer J, Diemers AD, and Bos NA
- Subjects
- Humans, Problem-Based Learning, Learning, Competency-Based Education, Curriculum, Students
- Abstract
Background: To train physicians who are able to meet the evolving requirements from health care, the University of Groningen Medical Center adopted in 2014 a new curriculum named G2020. This curriculum combines thematic learning communities with competency-based medical education and Problem-based learning. In the learning community program, different learning tasks were used to train general competencies. The challenge of this program was whether students acquire similar levels of learning outcomes within the different variations of the program., Method: We used the assessment results of three cohorts for the first two bachelor years. We used progress tests and written tests to analyze knowledge development, and the assessment results of seven competencies to analyze competence development. Concerning knowledge, we used the cumulative deviation method to compare progress tests and used the Kruskal-Wallis H test to compare written test scores between programs. Descriptive statistics are used to present all assessments of the students' competencies., Results: We observed similarly high passing rates both for competency and knowledge assessments in all programs. However, we did observe some differences. The two programs that focused more on competencies development underperformed the other two programs on knowledge assessment but outperformed on competencies assessment., Conclusion: This study indicates that it is possible to train students in different learning programs within one curriculum while having similar learning outcomes. There are however some differences in obtained levels between the different programs. The new curriculum still needs to improve by balancing variations in the programs and comparability of assessments across the programs., (© 2023. The Author(s).)
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- 2023
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39. Determinants of peer selection for collaborative group work of third-year bachelor students in a medical degree programme with learning communities.
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Zhou Y, Brouwer J, Bos NA, and Diemers AD
- Subjects
- Curriculum, Humans, Learning, Peer Group, Students, Education, Medical, Undergraduate, Students, Medical
- Abstract
The social capital theory reveals the importance of peer relationships on students' learning. However, it is unclear how students select their collaborators under the influence of their previous collaborations and backgrounds. This study explores to what extent students' free selection choices for collaborators among their peers are based on previous collaboration in formally structured groups (i.e., learning communities (LCs)) and based on different students' background characteristics. A parallel program was studied where students studied in one of four LCs for two years and after that, they have to find their own group members within or across LCs to finish their bachelor thesis in the third year. In total, 1152 students' selections of their peers were analyzed. This paper presents the percentages of students choosing group members within or across LCs. It also considered the influence of students' backgrounds, like sex, nationality, and academic performances on their peerchoices by logistic regression analysis. More than half of the students chose group members within their own LC, regardless of which LC they were in. Although the majority of the students chose collaborators within their own LC, still around 40% of students were willing to collaborate with others from different LCs with whom they had never collaborated before in the formal curriculum. Students' backgrounds (i.e., sex, and academic performance) were also associated with their decisions. A high frequency of collaboration within formally structured groups enhances the students' preference of group members from the same groups, but also informal peer relationships are crucial in students' choices for collaboration. Students' sex and academic performance influence their free choice of group members while nationality does not. Students with different academic levels have a higher chance to become group members when they collaborated before in formally structured groups than those students who had not had such a collaboration experience.
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- 2022
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40. The relationship between medical student engagement in the provision of the school's education programme and learning outcomes.
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Xu X, Bos NA, and Wu H
- Subjects
- Humans, Learning, Schools, Clinical Clerkship, Education, Medical, Students, Medical
- Abstract
Introduction: Student engagement in the provision of the school's education programme (educational student engagement) plays an important role in quality assurance in medical education. However, little is known whether this specific type of student engagement has effects on the learning outcomes for the involved medical students., Methods: This study was based on a national-wide survey in China among medical students with 123,055 responses. The questionnaire was designed using international and Chinese national standards. T-test, analysis of variance, multivariate regression, and regression with interaction terms were used., Results: Educational student engagement was positively associated with medical students' learning outcomes in Clinical Practice, Science and Scholarship, Health and Society, and Professionalism. Besides, the influence was heterogeneous among participants at different learning phases. Learning outcomes in Clinical Practice were strongly associated with educational student engagement efficiently at the Clinical Medical Education and the Clerkship Rotation phases, and learning outcomes in Science and Scholarship were best correlated with the Clerkship Rotation phase., Conclusion: Educational student engagement is positively associated with the learning outcomes, with the greatest effect on learning outcomes in Clinical Practice and the least effect in Professionalism. Besides, it has a greater impact on medical students at senior learning phases.
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- 2022
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41. Biological Characteristics of HLA-G and Its Role in Solid Organ Transplantation.
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Liu S, Bos NA, Verschuuren EAM, van Baarle D, and Westra J
- Subjects
- Female, Humans, Immune Tolerance, Placenta immunology, Pregnancy immunology, Protein Isoforms, HLA-G Antigens immunology, Organ Transplantation
- Abstract
Organ transplantation is a lifesaving option for patients with advanced diseases. Rejection is regarded as one of the most severe risk factors post-transplantation. A molecule that contributes to immune tolerance and resisting rejection is human leukocyte antigen (HLA)-G, which belongs to the non-classical major histocompatibility complex class (MHC) I family. HLA-G was originally found to play a role during pregnancy to maintain immune tolerance between mother and child. It is expressed in the placenta and detected in several body fluids as soluble factor as well as different membrane isoforms on cells. Recent findings on HLA-G show that it can also play multifaceted roles during transplantation. This review will explain the general characteristics and biological function of HLA-G and summarize the views supporting the tolerogenic and other roles of HLA-G to better understand its role in solid organ transplantation (SOT) and its complications. Finally, we will discuss potential future research on the role of HLA-G in prevention, diagnosis, and treatment in SOT., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Liu, Bos, Verschuuren, van Baarle and Westra.)
- Published
- 2022
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42. Changes in T and B cell subsets in end stage renal disease patients before and after kidney transplantation.
- Author
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Wang L, Rondaan C, de Joode AAE, Raveling-Eelsing E, Bos NA, and Westra J
- Abstract
Background: The incidence of kidney transplantation performed in elderly patients has increased steadily recently. Higher risk of infection and mortality, but lower rate of rejection, are reported in older kidney transplant patients. This study aims to analyze the effect of transplantation on aging of T and B cells in kidney transplant patients, with the emphasis on age and Cytomegalovirus (CMV) latency., Results: We included 36 patients before and after (median 2.7 years) kidney transplantation and 27 age- and sex-matched healthy controls (HC). T and B cell subsets were measured by flow cytometry, with a focus on aged T cells (CD28-), and age associated B cells (ABCs, CD19 + CD21-CD11c+). Three years after transplantation a significant increase of total T cells among the lymphocytes was found compared to pre-transplantation and HC. Among the T cells CD4+ cells were decreased, especially naïve CD4+ cells and regulatory T cells. Total CD8+ cell proportions were increased, and proportions of naïve CD8+ cells were significantly decreased after transplantation, while CD8+ effector memory T cells re-expressing CD45RA were increased. CD28- T cells were significantly higher compared to HC after transplantation, especially in CMV seropositive patients. B cells were significantly decreased, while among B cells memory B cells and especially ABCs were increased after transplantation., Conclusions: After transplantation T and B cell subsets change towards more terminally differentiated memory cells compared to age-matched HC. Proportions of aged T cells and ABCs were associated with CMV serostatus., (© 2021. The Author(s).)
- Published
- 2021
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43. B Cell Activation and Escape of Tolerance Checkpoints: Recent Insights from Studying Autoreactive B Cells.
- Author
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Bonasia CG, Abdulahad WH, Rutgers A, Heeringa P, and Bos NA
- Subjects
- Animals, Autoimmune Diseases metabolism, B-Lymphocytes metabolism, Humans, Immune Checkpoint Proteins metabolism, Phenotype, Autoimmune Diseases immunology, Autoimmunity, B-Lymphocytes immunology, Immune Checkpoint Proteins immunology, Immune Tolerance, Lymphocyte Activation
- Abstract
Autoreactive B cells are key drivers of pathogenic processes in autoimmune diseases by the production of autoantibodies, secretion of cytokines, and presentation of autoantigens to T cells. However, the mechanisms that underlie the development of autoreactive B cells are not well understood. Here, we review recent studies leveraging novel techniques to identify and characterize (auto)antigen-specific B cells. The insights gained from such studies pertaining to the mechanisms involved in the escape of tolerance checkpoints and the activation of autoreactive B cells are discussed. In addition, we briefly highlight potential therapeutic strategies to target and eliminate autoreactive B cells in autoimmune diseases.
- Published
- 2021
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44. Ageing of Immune System and Response to a Live-Attenuated Herpes Zoster Vaccine in Lung Transplant Candidates.
- Author
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Wang L, Verschuuren EAM, Paap D, Rondaan C, Raveling-Eelsing E, Liu S, Westra J, and Bos NA
- Abstract
The mean age of lung transplant recipients has significantly increased in recent decades. Elderly recipients have a higher risk of developing herpes zoster (HZ), and they have in general a worse response to vaccination than younger persons do. We investigated the relationship between the humoral and cellular immune response to a live-attenuated HZ vaccine (Zostavax
® , Merck Sharp and Dohme) and the frequencies of T and B cell subsets, especially aged cell subsets (CD28-T cells and age associated B cells, ABCs). In total, 37 patients awaiting lung transplantation received one dose of Zostavax® , and peripheral blood was collected before and within 6 months after vaccination. We observed a robust immune response after vaccination. The frequencies of CD28-T cells before vaccination had no impact on the subsequent immune response to HZ vaccination. However, a higher frequency of ABCs before vaccination correlated with a lower immune response especially regarding the cellular immune response. Cytomegalovirus seropositivity was associated with increased frequencies of CD28-T cells but not with frequencies of ABCs in the patients. In conclusion, increased levels of ABCs might disturb the cellular immune response to HZ vaccination, which could lower the efficacy of such vaccination in elderly transplant recipients.- Published
- 2021
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45. Prophylactic vaccination with a live-attenuated herpes zoster vaccine in lung transplant candidates.
- Author
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Wang L, Verschuuren EAM, Paap D, Rondaan C, Raveling-Eelsing E, Westra J, and Bos NA
- Subjects
- Adult, Aged, Female, Follow-Up Studies, Humans, Male, Middle Aged, Primary Graft Dysfunction immunology, Retrospective Studies, Treatment Outcome, Vaccines, Attenuated, Young Adult, Herpes Zoster Vaccine pharmacology, Herpesvirus 3, Human immunology, Immunity, Cellular, Lung Transplantation, Preoperative Care methods, Primary Graft Dysfunction prevention & control, Respiratory Insufficiency surgery
- Abstract
Background: Herpes zoster (HZ) is caused by the reactivation of varicella-zoster virus (VZV). Patients with lung transplants are at high risk for HZ owing to their immunocompromised status and the need for lifelong immunosuppression. In this study, patients on the waiting list for lung transplantation were vaccinated by a live-attenuated HZ vaccine (Zostavax, Merck Sharp & Dohme), and the safety and immunogenicity of this vaccine were studied., Methods: In total, 105 patients with end-stage pulmonary disease (ESPD) were enrolled (68 participants received 1 dose of Zostavax and 37 participants were enrolled as unvaccinated controls). Among them, 43 patients underwent lung transplantation and were followed up for further analysis. VZV immunoglobulin G antibody titers and VZV-specific cell-mediated immunity (CMI) on multiple time points before and after vaccination and before and after transplantation were measured., Results: Immune response to Zostavax was higher in younger patients, highest within 3 months after vaccination, and not influenced by gender or type of ESPD. Age, cytomegalovirus serostatus, and immunity to VZV at baseline impacted the subsequent immune response to the vaccine. Short-term immunosuppressant treatment had strong effects on VZV CMI levels, which returned to a high level at 6 months after transplantation in vaccinated patients. Zostavax did not impact infection or rejection rate after transplantation., Conclusions: Zostavax was safe and induced a robust humoral and cellular response for patients awaiting lung transplantation regardless of the type of ESPD. Patients younger than the recommended vaccination age of over 50 years showed a strong response and could also benefit from pre-transplant immunization., (Copyright © 2020 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.)
- Published
- 2020
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46. Immune response to varicella-zoster virus before and after renal transplantation.
- Author
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Rondaan C, de Joode AAE, Wang L, Siderius M, Raveling-Eelsing E, van Leer-Buter C, van Assen S, Bos NA, and Westra J
- Subjects
- Adult, Aged, Female, Humans, Male, Middle Aged, Antibodies, Viral blood, Herpesvirus 3, Human immunology, Immunity, Cellular, Immunity, Humoral, Kidney Transplantation statistics & numerical data
- Abstract
Background: Herpes zoster (HZ) risk is high in renal transplant recipients. Vaccination prior to transplantation may provide a useful strategy for the prevention of HZ in the posttranplantation period. However, it is not known whether immunity to varicella-zoster virus (VZV) is affected due to treatment surrounding transplantation., Methods: Both humoral and cellular immunity to VZV were determined prior to and 2-3 years after renal transplantation in 60 adult patients, and 62 matched healthy controls. VZV-specific cellular immunity was measured by an interferon gamma (IFNγ) enzyme-linked immunospot (ELISpot) assay and by analyzing T-cell functionality using flowcytometry. VZV-IgG levels were measured using an in-house glycoprotein enzyme-linked immunosorbent assay (gpELISA)., Results: Using paired analysis, it was determined that numbers of IFNγ-producing cells did not change after transplantation, but were significantly lower in transplant recipients after transplantation than in controls (p = 0.028). Patients in whom the post-transplant period was complicated by rejection or any acute infection (excluding HZ) had a lower number of IFNγ-producing cells than patients who did not. VZV IgG levels did not differ from controls, but a significant decrease was observed after transplantation (p < 0.0001)., Conclusions: VZV-specific cellular immunity, which is essential in the prevention of HZ, did not markedly change in patients following renal transplantation. This suggests that preventive vaccination before transplantation may be beneficial. Our results extend knowledge on VZV immunity after transplantation, vital when considering strategies for the prevention of HZ in these patients., (Copyright © 2020 The Author(s). Published by Elsevier B.V. All rights reserved.)
- Published
- 2020
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47. The influence of mixing international and domestic students on competency learning in small groups in undergraduate medical education.
- Author
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Zhou Y, Diemers AD, Brouwer J, Muntinghe FLH, Duvivier RJ, Pols J, Jaarsma ADC, and Bos NA
- Subjects
- Curriculum, Humans, Learning, Professionalism, Education, Medical, Undergraduate, Students, Medical
- Abstract
Background: Medical curricula are increasingly internationalized, with international students being mixed with domestic students in small group learning. Small group learning is known to foster competency learning in undergraduate medical education, specifically Communication, Collaboration, Leadership, and Professionalism. However, it is unclear what happens with the learning of competencies when international students are introduced in small groups. This study explores if students in international small groups master the competencies Collaboration, Leadership and Professionalism at the same level as students in domestic groups in an undergraduate medical curriculum., Method: In total, 1215 Students of three academic year cohorts participated in the study. They were divided into four learning communities (LCs), per year cohort, in which tutor groups were the main instructional format. The tutorials of two learning communities were taught in English, with a mix of international and Dutch students. The tutorials of the other two learning communities were taught in Dutch with almost all domestic students. Trained tutors assessed three competencies (Collaboration, Leadership, Professionalism) twice per semester, as 'Not-on-track', 'On-track', or 'Fast-on-track'. By using Chi-square tests, we compared students' competencies performance twice per semester between the four LCs in the first two undergraduate years., Results: The passing rate ('On-track' plus 'Fast-on-track') for the minimum level of competencies did not differ between the mixed and domestic groups. However, students in the mixed groups received more excellent performance evaluations ('Fast-on-track') than the students in the homogenous groups of Dutch students. This higher performance was true for both international and Dutch students of the mixed groups. Prior knowledge, age, gender, and nationality did not explain this phenomenon. The effect could also not be explained by a bias of the tutors., Conclusion: When students are educated in mixed groups of international and Dutch students, they can obtain the same basic competency levels, no matter what mix of students is made. However, students in the mixed international groups outperformed the students in the homogenous Dutch groups in achieving excellent performance scores. Future research should explore if these findings can be explained from differences in motivation, perceived grading or social network interactions.
- Published
- 2020
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48. Repertoire Analysis of B-Cells Located in Striated Ducts of Salivary Glands of Patients With Sjögren's Syndrome.
- Author
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Visser A, Verstappen GM, van der Vegt B, Vissink A, Bende RJ, Bootsma H, Bos NA, and Kroese FGM
- Subjects
- Adult, Aged, Clone Cells, Female, Gene Rearrangement, B-Lymphocyte, Humans, Lymphocyte Activation, Middle Aged, Receptors, Fc metabolism, B-Lymphocytes physiology, Immunoglobulin Heavy Chains genetics, Lymphoma, B-Cell, Marginal Zone immunology, Rheumatoid Factor genetics, Salivary Ducts immunology, Salivary Glands immunology, Sjogren's Syndrome immunology
- Abstract
A major complication of primary Sjögren's syndrome (pSS) is development of mucosa associated lymphoid tissue (MALT) B-cell lymphoma, particularly in salivary glands. These lymphomas express FcRL4 and are characteristically associated with lymphoepithelial lesions. Neoplastic B-cells may be derived from non-neoplastic glandular intraductal B-cells, also virtually all expressing FcRL4. A characteristic feature of MALT lymphomas is the production of rheumatoid factors (RFs), which are largely encoded by stereotypic immunoglobulin variable heavy chain (IGHV) sequences. The aim of this study was to examine whether there is a relationship between the intraductal and periductal B-cells and whether the intraductal B-cells are selected for RF. RNA was extracted from laser-microdissected infiltrated ductal areas and periductal infiltrates from frozen parotid gland tissue sections of 5 pSS patients. PCR amplified IGHV transcripts were cloned into pCR™4-TOPO vector and subsequently sequenced. Microdissected ducts yielded 96 unique IGHV sequences derived from intraductal B-cells, while 119 unique IGHV sequences were obtained from periductal infiltrates. No major difference in VH-gene usage was observed between intraductal and periductal B-cells. Nearly all (>90%) IGHV sequences derived from both intraductal and periductal B-cells were mutated. Clonal expansions as defined by shared VDJ rearrangements were also present among both intraductal and periductal B-cells: in total 32 clones were found, from which 12 were located within ducts, 15 in periductal areas, and five clones shared members in both areas. We observed 12 IGHV rearrangements encoding for RF sequences from which two were derived from intraductal B-cells and 10 from periductal B-cells. Nine RF sequences were part of a clone. Together these findings indicate that intraductal and periductal B-cells are closely related to each other. Intraductal B-cells are most likely derived from periductal B-cells. We did not obtain evidence that RF-specific B-cells are enriched within the striated ducts. We speculate that in principle any activated B-cell can enter the striated ducts from the periductal infiltrate, irrespective of its antigenic specificity. Within the ducts, these B-cells may receive additional activation and proliferation signals, to further expand at these sites and by acquisition of driver-mutations develop toward lymphoma., (Copyright © 2020 Visser, Verstappen, van der Vegt, Vissink, Bende, Bootsma, Bos and Kroese.)
- Published
- 2020
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49. The formation of mutated IgM memory B cells in rat splenic marginal zones is an antigen dependent process.
- Author
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Hendricks J, Visser A, Dammers PM, Burgerhof JGM, Bos NA, and Kroese FGM
- Subjects
- Animals, Antigens immunology, Immunoglobulin M immunology, Immunoglobulin Variable Region genetics, Immunoglobulin Variable Region metabolism, Male, Rats, Spleen cytology, B-Lymphocytes immunology, Immunoglobulin M genetics, Immunologic Memory, Mutation, Spleen immunology
- Abstract
Previous studies in rodents have indicated that only a minor fraction of the immunoglobulin heavy chain variable region (IGHV-Cμ) transcripts carry somatic mutations and are considered memory B cells. This is in marked contrast to humans where nearly all marginal zone B (MZ-B) cells are mutated. Here we show in rats that the proportion of mutated IgM+ MZ-B cells varies significantly between the various IGHV genes analyzed, ranging from 27% mutated IGHV5 transcripts to 65% mutated IGHV4 transcripts. The observed data on mutated sequences in clonally-related B cells with a MZ-B cell or follicular B (FO-B) cell phenotype indicates that mutated IgM+ MZ-B and FO-B cells have a common origin. To further investigate the origin of mutated IgM+ MZ-B cells we determined whether mutations occurred in rearranged IGHV-Cμ transcripts using IGHV4 and IGHV5 genes from neonatal rat MZ-B cells and FO-B cells. We were not able to detect mutations in any of the IGHV4 and IGHV5 genes expressed by MZ-B cells or FO-B cells obtained from neonatal rat spleens. Germinal centres (GCs) are absent from neonatal rat spleen in the first few weeks of their life, and no mutations were found in any of the neonatal sequences, not even in the IGHV4 gene family which accumulates the highest number of mutated sequences (66%) in the adult rat. Therefore, these data do not support the notion that MZ-B cells in rats mutate their IGHV genes as part of their developmental program, but are consistent with the notion that mutated rat MZ-B cells require GCs for their generation. Our findings support that the splenic MZ of rats harbors a significant number of memory type IgM+ MZ-B cells with mutated IGHV genes and propose that these memory MZ-B cells are probably generated as a result of an antigen driven immune response in GCs, which still remains to be proven., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2019
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50. Increased incidence of herpes zoster in patients on renal replacement therapy cannot be explained by intrinsic defects of cellular or humoral immunity to varicella-zoster virus.
- Author
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Rondaan C, de Joode AAE, van Assen S, Bos NA, Westerhuis R, and Westra J
- Subjects
- Adult, Age Factors, Aged, Aged, 80 and over, Antibodies, Viral immunology, Cell Proliferation, Cytokines metabolism, Female, Herpes Zoster virology, Humans, Immunity, Cellular immunology, Immunoglobulin G blood, Incidence, Interferon-gamma metabolism, Kidney Transplantation, Leukocytes, Mononuclear, Male, Middle Aged, Peritoneal Dialysis, Regression Analysis, Renal Dialysis, Sex Factors, T-Lymphocytes immunology, Young Adult, Herpes Zoster immunology, Herpesvirus 3, Human immunology, Immunity, Humoral, Renal Replacement Therapy
- Abstract
Background: Patients in need of long-term renal replacement therapy (RRT) are known to be at increased risk of herpes zoster, occurring when the latently present varicella-zoster virus (VZV) reactivates. In this study we investigated immunity to VZV in patients receiving RRT, with the aim of better understanding the mechanism behind the increased risk., Methods: Patients treated for at least three months with hemodialysis or peritoneal dialysis, and matched healthy controls (HC) were included. Cellular immunity to varicella-zoster virus (VZV) was studied using an interferon-γ (IFNγ) enzyme-linked immunospot (ELISpot) assay, flow-cytometric analysis of cytokine production and a proliferation assay. Humoral immunity was determined by measuring immunoglobulin (Ig)G antibody levels to VZV using an in-house glycoprotein enzyme-linked immunosorbent assay (ELISA). Multiple regression was used to assess variables of influence on measures of cellular and humoral immunity to VZV in patients receiving RRT., Results: Similar numbers of IFNγ spot-forming cells and levels of VZV-IgG were found in 97 patients and 89 HC. Age and transplantation history were negatively associated with cellular immunity (p = 0.001 and p = 0.012, respectively) while treatment modality, gender and urea levels were not. No variables were found to be associated with VZV-IgG levels., Conclusions: Increased incidence of herpes zoster in patients receiving RRT cannot be explained by intrinsic defects of cellular or humoral immunity to VZV as measured by the methods used in this study, although older age and previous transplantation were associated with decreased cellular immunity to VZV. Herpes zoster susceptibility might be caused by a diminished function of otherwise capable T cells in a uremic environment., (Copyright © 2018. Published by Elsevier B.V.)
- Published
- 2018
- Full Text
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