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Kupffer cells, ED2+ macrophages of the liver, play an important role in liver damage and regeneration. It is proposed that Kupffer cells are stationary and regenerate after acute liver trauma by local proliferation. We analyzed their kinetics in three surgically relevant murine models of acute liver injury: partial liver resection, ischemia with reperfusion and sepsis. We found an early increase in ED2+ cells after 0.5 h and a maximum after 12 h. These results suggest an infiltration of the cells early after the injury and a later local proliferation. These ED2+ macrophages are localized predominantly periportally; nearly no macrophages are found pericentrally, except in the sepsis model. Therefore, a shifting of macrophages from portal to central seems to be unlikely, suggesting a hepatic zonation of homing factors. Copyright © 2005 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

SUMMARY CVID is characterized by reduced serum levels of all switched immunoglobulin isotypes (IgG, IgA, IgE) predisposing patients to recurrent infections of their respiratory and gastrointestinal tract. Correspondingly, most CVID patients exhibit a severely decreased proportion of class switched memory B cells (CD19+ CD27+ IgD- IgM- IgG+ or IgA+ ) in their peripheral blood (CVID type I). We previously identified a subgroup of CVID patients showing a significantly reduced expression of CD86 and CD137 following activation in vitro of PBMC or purified B cells (CD19+ ) with anti-IgM plus IL-2. Here we extend our previous studies by asking whether highly purified, cell-sorted naive B cells show already an expression defect of B cell surface molecules relevant in activation (CD39, CD69), differentiation (CD24, CD27, CD38) or T–B interaction (CD25, CD70, CD86). We stimulated cell-sorted, naive B cells (CD19+ CD27- IgM+ IgDhigh IgG- IgA- ) from 10 CVID patients and 10 healthy controls for 4 days with anti-IgM plus IL-2 in the absence or presence of autologous CD4+ T cells and measured the expression of the referred surface molecules. Based on reduced or normal numbers of switched memory B cells the CVID patients had previously been classified into eight type I patients and two type II patients, respectively. Interestingly, only the molecules CD25, CD70 and CD86, all relevant in cognate T–B interaction, showed a significantly lower expression in naive B cells from CVID patients compared to controls. While coculture with autologous CD4+ T cells normalized the CD25 expression, CD70 and CD86 expression remained subnormal, notably in the eight CVID patients of type I. These findings strongly suggest an intrinsic signalling or expression defect for CD70/CD86 at the level of naive B cells in type I... [ABSTRACT FROM AUTHOR]

Introduction: In necrotizing acute pancreatitis (NAP), systemic inflammatory response syndrome (SIRS) and the compensatory anti-inflammatory response syndrome (CARS) decide overall outcome and mortality. In patients, low lymphocyte counts were found, but T-helper cells seemed to conversely increase. Our aim was to further categorize T-helper cells within the context of NAP induced SIRS and CARS., Methods: NAP was induced by injection of sodium-taurocholate into the common bile duct of male BALB/c mice; sham treated animals received saline infusion. The animals were sacrificed at 6, 12, 24 and 48 h later. Lymphocytes from blood, liver and spleen were isolated and examined by flow cytometry. Staining was performed for CD4, CD8, CD19, CD45RB, CD25, CD69, and CD152. CD4 + cells were sorted for their CD45RB expression and sought for gene regulation associated to T H1 /T H2 cells by quantitative RT-PCR., Results: In NAP, CD4 + was solely increased in all compartments. CD8 + remained without substantial alterations. CD45RB showed significant expression in RB high in T-helper cells, confirmed by the CD45RB high/low ratio (Liver, 24 h: NAP 2.2, SHAM 0.6; p < 0.001). CD45RB high and -low cells were not associated to patterns of T H1 /T H2 expression. In NAP, CCR4 expression was significantly decreased within RB high cells (fold change: 0.04, p < 0.05), while TLR6 showed significant overexpression (fold change: 2.36, p < 0.05)., Conclusion: T-helper cells increase in NAP, leaning towards CD45RB high expression. They resemble naive T-cells, in which NAP leads to expression profiles associated with an innate immune response. This suggests new findings in immunological pathomechanisms of NAP., (Copyright © 2017 IAP and EPC. Published by Elsevier B.V. All rights reserved.)

Background: Patients with pancreatic carcinoma have a grim prognosis. Here, we examine the induction of an in vitro antibody response of human B cells to pancreatic carcinoma antigens., Material and Methods: Cells of five cultured pancreatic ductal adenocarcinoma lines were lysed and their plasma membrane fragments isolated in an aqueous two-phase-system. The plasma membrane fragments were then added to cultures of isolated peripheral blood mononuclear cells from healthy volunteers for 14 days to act as a tumor antigen. Also, we added combinations of IL-2, IL-4, IL-21, anti-CD40 mAb and varying protein concentrations of the plasma membrane fragments to these cultures. We then tested characteristics and binding of resulting IgG and IgM against aforementioned tumor plasma membrane fragments and their respective cells using ELISAs., Results: The combination of IL-2, IL-4 and anti-CD40 mAb elicited IgM production showing significant binding (p<0.05) to plasma membrane fragments. PANC-1 antigen and the combination of IL-4, IL-21 and anti-CD40 mAb was able to produce a significant and specific IgG formation against PANC-1 plasma membrane fragments (p<0.05). Tumor antigen, interleukins and anti-CD40 mAb had a significant impact on the binding capacity of these antibodies (p<0.05). IgG binding pancreatic carcinoma cells was observed when the tumor antigen concentration was increased during stimulation (p<0.05). BxPC3 plasma membrane fragments showed inhibitory effects on IgG binding BxPC3 antigens (p<0.05)., Conclusions: A human anti-tumor antibody formation can be induced in vitro using PANC-1 antigens and B cell stimulating agents. This response has the potential to generate antibodies specific to PANC-1 antigens. PRéCIS: The concept presented is novel and a promising approach to eliciting a specific B cell response to tumor antigen. The method may prove useful in understanding and developing anti-tumor immunity., (Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Acute necrotizing pancreatitis (NAP) induces a systemic inflammatory response syndrome. We investigated the underlying changes of monocytes using different activation markers., Materials and Methods: A retrograde injection of 2 mL/kg bodyweight of sodium taurocholate into the common bile duct of BALB/c mice induced NAP, whereas sham-operated animals (SOP) were treated with saline. After 6, 12, 24, and 48 h, histologic alterations, pancreatic enzymes, and interleukin 6 in serum, albumin, and myeloperoxidase (MPO) in bronchoalveolar lavage fluid were examined. Isolation of mononuclear cells from the blood, spleen, and liver and the subsequent determination of macrophages (F4/80) and their activation marker CD121b and MHCII (1Ad) were performed by fluorescence-activated cell sorting (FACS analyses)., Results: After pancreatitis induction, pancreatic enzymes (amylase: SOP 7008 U/L, NAP 37,044 U/L, P < 0.001) and histologic pancreatic damage (SOP 0.80 ± 1.92, NAP 19.6 ± 0.64, P < 0.001) developed instantly. Pulmonary vascular damage and MPO were detected between 6 and 12 h after onset (6 h albumin SOP 132.0 ± 12.0 μg/mL, NAP 267.2 ± 49.6 μg/mL; P < 0.05; MPO SOP 0.23 ± 0.20 ng/mL, NAP 11.29 ± 3.12 ng/mL, P < 0.01). Blood levels of interleukin 6 increased after 12-24 h (12 h SOP 584 ± 300 pg/mL; NAP 2169 ± 942 pg/mL, P < 0.05), whereas monocytes increased fourfold within 48 h (P < 0.05). Furthermore, pancreatitis increased the percentage of activated monocytes in the blood (6 h and/or 48 h: MHCII (1Ad) 2196%/5.65%; CD121b 51,654%/82,146%). Similar observations were made for monocytes from the liver and spleen., Conclusions: Although inflammatory mediators increased during 24 h after pancreatitis induction, monocyte activation lasted for at least 48 h. The latter is not limited to blood but also detected in isolated liver and spleen monocytes., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Background/aims: In this paper the early phase of proliferate response and apoptosis of hepatocytes after partial liver resection, during reperfusion after ischemia and during sepsis is demonstrated., Methodology: Experiments were conducted in a rat model with regeneration times of 0.5-24 hours after injury. Proliferation was analyzed by Ki-67 immunohistochemistry and confirmed by double staining with CK18 in FACS. Apoptosis was analyzed by TUNEL technique., Results: Periportal hepatocytes enter the cell cycle already 0.5-2 hours after injury in all three models. This early proliferative response is predominant periportally localized. During reperfusion and during sepsis there was a strict pericentral apoptosis of hepatocytes found., Conclusions: An early periportal proliferation of hepatocytes is a common reaction of the liver to injury. This proliferation takes place much earlier then the main proliferative response 24-72 h after partial resection. This predominant periportal proliferation together with the pericentral apoptosis fit to the concept of the "streaming liver" in liver regeneration.

Background: Chemokines (CKs) may promote antitumor immunity in cancer, act as tumor growth factors, influence metastatic spreading or angiogenesis. The purpose of this study was to investigate whether CK expression is altered in colorectal carcinomas compared to normal mucosa and to elucidate its possible clinico-pathological implications., Materials and Methods: The levels of CCL2 (MCP-1), CCL4 (MIP-1beta), CCL5 (RANTES), CXCL 1 (GRO-alpha), CXCL 5 (ENA-78) and CXCL 8 (IL-8) were investigated in 10 colorectal carcinomas and their corresponding normal mucosa by the use of ELISA., Results: All CK analyzed, with the exception of CCL5 (RANTES), were expressed at a significantly higher level in malignant tissue., Conclusion: Therapeutic studies in colon carcinomas should, therefore, focus more on the neutralization of CKs than on their application.

Background: Cytokines reflect the activity of the immune system. We analyzed the local expression of characteristic cytokines indicating the level of activity of unspecific inflammatory cells, Th1-cells and Th2-cells in colon cancer., Materials and Methods: In 25 tumor/ mucosa pairs, IL-1alpha, IL-2, IL-4, IL-5, IL-15, TNF-alpha and IFN-gamma were measured by real-time PCR., Results: There was a significant increase in IL-1alpha, IL-4, IL-5 and TNF-alpha and a significant decrease in IL-2 in tumor tissue compared to normal mucosa., Discussion: The cytokine profile in colon cancer indicates a strong unspecific inflammatory reaction in the tumor tissue represented by high levels of IL-1 and TNF-alpha. The comparatively low level of IL-2 suggests suppression of a specific immunological reaction, namely Th1-cells. It can be hypothesized that this is a result and/or cause of local immune escape mechanisms. Furthermore, there is an activation of TH2 cells in the carcinomas.

Background: The aim of this study was to evaluate the influence of taurolidine (TAU) and polyhexanid (POLY) on basic inflammatory reactions during peritonitis by using an in vitro model of human peritoneum., Materials and Methods: Human umbilical vein endothelial cells (HUVEC) and human peritoneal mesothelial cells (HPMC; concentration: 2x10(5)/cm2) were brought on a collagen-coated filter insert with 3-microm pore size (HUVEC on the bottom, HPMC on the top), thus resulting in a two-chamber peritoneal model. After 5 days, confluence of the cells was reached, and HPMC were stimulated with 0.5 mL of TNF-alpha (10 microg/mL) for 4 h. Afterwards, 0.5 mL of TAU (1% and 2%) or 0.5 mL of POLY (0.1% and 0.2%) solution were added to the upper (HPMC) compartment. Polymorphonuclear neutrophils (PMN, 10(6)/mL) were placed in the lower compartment 1 h later. After 2 and 6 h, aliquots were taken from the upper compartment and transmigrated PMN were counted. Interleukin-8 (IL-8) concentrations were measured in both compartments by chemiluminescent enzyme immunometric assay. Expression of the adhesion molecules P-selectin and intercellular adhesion molecule-1 (ICAM-1) was assessed by immunohistochemistry. Controls were either TNF-alpha-stimulated HPMC without any antiseptic agents, or stimulated HPMC where TNF-alpha had been substituted by culture medium. Each experiment was performed in triplicate., Results: Stimulation with TNF-alpha led to a time-dependent increase of IL-8 secretion to the apical compartment resulting in a gradient between both chambers, as well as to a time-dependent increase of PMN transmigration and expression of adhesion molecules. IL-8 gradients and PMN migration were significantly higher as compared to the other groups (p<0.05). After substitution of the stimulus by culture medium, significantly less IL-8 was measured in both compartments. PMN transmigration was almost absent (p<0.05). Addition of POLY and TAU led to comparable low IL-8 gradients with concomitant low PMN transmigration. The initially detected expression of adhesion molecules significantly decreased during the observation time. The IL-8 gradient in all groups correlated significantly with PMN transmigration (r=0.74226; p<0.0001)., Conclusion: The diminished IL-8 response together with low PMN transmigration rates after addition of TAU and POLY may reflect either antiinflammatory effects or cellular damage.

Hypogammaglobulinemia is the hallmark of common variable immunodeficiency (CVID) syndrome, a heterogeneous disorder predisposing patients to recurrent bacterial infections. In this study, we investigated the peripheral B-cell compartment of 30 well-characterized CVID patients in comparison to 22 healthy controls. Flow cytometric analysis of peripheral blood lymphocytes revealed a reduction of class-switched CD27(+)IgM(-)IgD(-) memory B cells below 0.4% in 77% of our patients (group I), while this B-cell subpopulation exceeded 0.5% in all healthy donors and in 23% of CVID patients (group II). These results correlate well with the capacity of peripheral blood lymphocytes to produce immunoglobulins in vitro upon stimulation with Staphylococcus aureus Cowan I (SAC) plus interleukin-2 because the production of immunoglobulin G in vitro is entirely dependent on the presence of switched memory B cells. The subdivision of group I into patients with an increased proportion of CD21(-) peripheral B cells (> 20%; group Ia) and patients with normal percentages of CD21(-) B cells (< 20%; group Ib) revealed a significant clustering of patients with splenomegaly and autoimmune cytopenias in group Ia. Based on these observations, we propose a fast and reliable new classification for CVID patients by flow cytometric quantification of class-switched memory and immature B cells in the peripheral blood of patients. Our results point toward defects at various stages of B-cell differentiation in CVID subgroups and support the value of a B-cell-oriented classification principle. A consensus on this new classification system will hopefully provide a tool for rapidly defining homogeneous subgroups of CVID for functional studies and genetic linkage analysis.

Hepatitis C virus (HCV) is a major cause of chronic hepatitis worldwide, but the study of HCV infection has been hampered by the lack of an in vitro or in vivo small animal model. The tree shrew Tupaia belangeri is susceptible to infection with a variety of human viruses in vivo, including hepatitis viruses. We show that primary Tupaia hepatocytes can be infected with serum- or plasma-derived HCV from infected humans, as measured by de novo synthesis of HCV RNA, analysis of viral quasispecies evolution, and detection of viral proteins. Production of infectious virus could be demonstrated by passage to naive hepatocytes. To assess whether viral entry in Tupaia hepatocytes was dependent on the recently isolated HCV E2 binding protein CD81, we identified and characterized Tupaia CD81. Sequence analysis of cloned Tupaia cDNA revealed a high degree of homology between Tupaia and human CD81 large extracellular loops (LEL). Cellular binding of E2 and HCV infection could not be inhibited by anti-CD81 antibodies or soluble CD81-LEL, suggesting that viral entry can occur through receptors other than CD81. Thus, primary Tupaia hepatocytes provide a potential model for the study of HCV infection of hepatocytes.

Despite advances in the therapy of chronic hepatitis C for some hepatitis C virus (HCV) genotypes interferon and ribavirin combination therapy is effective in less than 50% of patients. Abnobaviscum Quercus (AQ) is a mistletoe preparation containing defined amounts of mistletoe lectins (ML). It has shown immunomodulatory properties in vitro and in vivo. In small clinical trials AQ resulted, within an anthroposophical treatment concept, in a biochemical or virological response in up to 40% of patients with chronic hepatitis C. In order to evaluate the effect of this preparation we conducted an individually controlled cohort study. 25 patients with chronic hepatitis C (mean duration 147 +/- 80 months) and elevated alanine aminotransferase (ALT) levels were included in the study. As control they were observed for 6 months pre-treatment. This pre-treatment period was followed by 6 months of active treatment in which the mistletoe preparation was subcutaneously injected three times a week. Main outcome parameters were normalization of ALT and viral load. Hepatitis C associated signs and symptoms like tiredness, fullness in the right upper abdomen and musculoskeletal pain were assessed monthly in a standardized questionnaire. All 25 patients completed the study and most of the patients wanted to continue treatment. Mean duration of treatment was 9.1 months. None of the patients had complete or partial normalization of ALT or HCV RNA levels during pre-treatment or treatment period. Mean ALT did not change during the study. Tiredness, fullness in the right upper abdomen and musculoskeletal pain were present in 18, 8 and 4 patients respectively. They significantly improved within two months of treatment. A significant eosinophilia (p=0.0001) occurred between month 2 and 6 during treatment. 9 month treatment with a ML containing mistletoe preparation has no effect on viral load or ALT as markers of activity in patients with chronic hepatitis C. However, frequency and intensity of clinical signs and symptoms in our patients decreased significantly, similar to reports of improved quality of life in tumour patients treated with such preparations. A significant eosinophilia suggests that ML containing mistletoe preparations induce a T-helper 2 immune response.

We developed an in vitro model of the peritoneum by coculturing human umbilical vein endothelial cells (HUVEC) and human peritoneal mesothelial cells (HPMC) to gather information on peritoneal physiology and to closer reflect the in vivo situation in humans. HUVEC and HPMC were seeded on collagen-coated polytetraflourethylene-insert membranes of pore size 3 microm. HUVEC were grown on the bottom of the membrane and HMPC on the top. The confluent cells were monitored by measuring transepithelial resistance and by confocal microscopy. The transmigration of PMNs as an important mechanism during secondary peritonitis was studied in this two-chamber model. PMNs were isolated by density separation. After stimulation of HMPC with the complement factor 5 split product C5a (1 ng/ml) or tumor necrosis factor-alpha (TNF-alpha; 10 or 50 microg/ml) for 1 h, 1 x 10(6) PMN were given to the lower compartment. Controls were cocultured cells without stimulation. After 1, 2, and 6 h nonadherent PMNs in the upper compartment were harvested and counted, interleukin-8 was measured in each compartment, and cells on the membrane were paraffin-embedded for immunohistochemistry. Each experiment was performed four times. Cells grew to confluence within 2-5 days and were detected on their respective seeding side by CD34 and cytokeratin 18 counterstaining. Transmigration of PMNs after C5a or TNF-alpha stimulation showed a significant time-dependent increase between 1 h and 6 h (P<0.05). PMNs were found in significantly higher numbers after stimulation with either C5a or TNF-alpha at 1, 2, and 6 h than without stimulation. After stimulation of HPMC, interleukin-8 secretion to the apical compartment increased in a time-dependent fashion, resulting in a gradient between the two chambers. Linear regression analysis revealed significant correlation between transmigrated PMN and interleukin-8 in stimulated cocultures; no correlation was found in controls. This new in vitro peritoneum consisting of cocultured mesothelial and endothelial cells may allow more detailed assessment of peritoneal pathophysiology. Generation of an interleukin-8 gradient affecting the migration of PNMs across the cocultured membrane represents a parameter which may be addressed in further studies.

Introduction: The prognostic significance of tumor DNA ploidy and cell cycle analysis for long-term survival has been examined in 19 patients with liposarcoma or malignant fibrous histiocytoma. In many cases, different tumor areas of primary tumors and local recurrences have been analyzed to reveal intratumoral heterogeneity., Results: Among the primary tumors, there were eight aneuploid tumors, three of which showed diploid and aneuploid tumor regions. Correlations among DNA ploidy, grading, percentage of S-phase cells and infiltrative growth pattern of the tumors could be demonstrated. Poorly differentiated tumors (G3) showed aneuploidy in six of eight patients. Aneuploid tumors showed S-phase cells in 17.2% (range 3.2-38.1%), which was higher than the percentage of S-phase cells in diploid tumors (9.4%, range 2.1-27.4%). Aneuploid tumors showed a more infiltrative growth pattern (6 of 8 patients) than diploid tumors (6 of 11 patients). The median survival time of patients with diploid tumors was 86.5 months (8-144 months), compared with 40.9 months (11-54 months) for patients with aneuploid tumors., Conclusion: DNA ploidy and percentage of S-phase cells may be considered as prognostic factors.

Human cytomegalovirus (HCMV) strains can be classified into four genotypes of the glycoprotein B (gB). In a previous study, the gB genotype 1 was found more frequently in bone marrow transplant recipients with nonfatal HCMV infection than in patients who died from HCMV disease [Fries et al. (1994): Journal of Infectious Diseases 169:769-774]. The distribution and cell tropism of different gB types in vivo were investigated. The gB type of HCMV was determined in blood or urine specimen from 76 organ and 47 bone marrow transplant recipients using PCR and restriction fragment length polymorphism (RFLP). The leukocyte populations (polymorphonuclear leukocytes, monocytes, T lymphocytes, non-T lymphocytes) of 20 viremic patients were purified by a fluorescence-activated cell sorter (FACS) and examined for HCMV infection by PCR. Sequence analysis of four randomly selected strains showed that gB types were similar to published sequences and no atypical gB types were found. Within the compartments blood and urine, the gB types were almost equally distributed, whereas the gB type 1, in contrast to gB types 2 and 3, did not infect T lymphocytes in vivo. These data show that the gB type correlates with viral tropism in vivo and thus provides further evidence that the gB variation may indeed influence the virulence of HCMV.

The cellular adhesion molecules (CAMs) CD44s, CD44v6, CD44v10, ICAM-1 and N-CAM were immunohistologically detected in colorectal cancers using the APAAP method. The expression of CD44s and CD44v6 was associated with the presence of lymph node metastases in the examined tumors. The pattern of ICAM-1 expression was inversely related to that of CD44, i.e. lower numbers of ICAM-1 positive cells were observed in metastasizing tumors. An intense focal staining of N-CAM was observed in the majority of the metastasizing tumors. The expression of CD44v, ICAM-1 or N-CAM on tumor cells did not correlate with the density of the tumor-infiltrating lymphocytes (TIL) within the tumors. The flowcytometric analysis of TIL showed a significant accumulation of CD25+ and HLA-DR+ cells and a reduced number of CD45RA+ cells as compared to autologous peripheral blood lymphocytes (PBL) or intraepithelial lymphocytes of the colon mucosa (IEL). These phenotypic characteristics of TIL did not correlate with the CAMexpression on tumor cells.

Long-term graft survival is mainly influenced by early graft rejection and posttransplant graft function. The ability of both complement-dependent cytotoxicity cross-match (CDC) and flow cytometry cross-match (FCXM) to predict acute rejection episodes has been evaluated by cross-matching 40 patients who received cadaveric kidney transplants, before (current serum) and after transplantation (on days 1, 7, 14, 21, 28, 60, and 90). Of the 40 patients, all of whom had a negative CDC before transplant, seven patients had a positive FCXM before transplant: five of them (5/7=71.4%) experienced severe rejection within 2 months after transplantation. In patients with a negative FCXM before transplant, the incidence of acute rejection was lower (25.8%). Pre-transplant FCXM recipients who had a positive FCXM after transplant, experienced more frequent rejection (38.5%) than those pre-transplant FCXM recipients who never had a positive FCXM (15.8%). With respect to the incidence of acute graft rejection, no difference was found between patients who had a positive CDC after transplant and those who had a negative CDC after transplant. Patients who had a positive FCXM before transplant had significantly higher creatinine levels within the first month after transplant. Immediate onset of function and accelerated lowering of the creatinine level were found to be more frequent in patients who had a negative FCXM before transplant. As early graft rejection is the largest contributing factor for the development of chronic rejection and, therefore, of graft loss, we regard FCXM as a sensitive method for predicting long-term prognosis and graft survival, due to its competence in predicting both restricted graft function and early acute rejection, in particular.

An autoreactive T cell clone derived from a patient with reactive arthritis, two alloreactive T cell lines, two antigen-specific T cell lines and allogeneic resting T cells were analyzed for their responses to monocytes and macrophages derived from monocytes by in vitro differentiation. The autoreactive T cell clone strongly proliferated in response to fresh monocytes and to macrophages derived from a 7 day culture, but only poorly to monocytes cultured for 2 days. In contrast, alloreactive and antigen-specific T cell lines proliferated to all stimulatory cells equally well. Finally, primary mixed lymphocyte reactions could be stimulated by both fresh and 2-day cultured monocytes, but not by in vitro derived macrophages. The impaired response of the autoreactive T cell clone to 2-day cultured monocytes could not be attributed to reduced expression of several well-defined surface molecules nor to induction of nonresponsiveness. Neither allogeneic monocytes nor cytokines (IL-1, IL-2, IL-4, IL-6) could correct the defective response of the autoreactive T cell clone. However, preculture of monocytes in the presence of interferon-gamma, IL-1, IL-4 or IL-6 retained their stimulatory capacity. Our interpretation of the selectively impaired response of the autoreactive T cell clone is that it most likely recognizes a differentiation-dependent monocyte/macrophage-specific peptide.

Oxidative burst was defective in 50% of peripheral blood neutrophils in a case of Sweet syndrome with leukemoid granulocytosis. Phagocytosis was normal. We suggest that the decreased ability to produce oxygen radicals observed in this patient might lead to a compensatory recruitment of hematopoietic growth factors. Consecutive activation, increased chemotaxis and adhesion of polymorphonuclear granulocytes might be the cause of the neutrophilic dermal infiltrate of Sweet syndrome.

By subtractive screening of a library made from mRNA of lipopolysaccharide (LPS)-stimulated mouse B lymphocytes we isolated cDNA-clones encoding the ribosomal protein L7. Human L7 mRNA was cloned from activated T-lymphocytes. Although no specific function of L7 in the translation apparatus is known as yet, it should be a critical one as indicated by its high degree of structural conservation during evolution and its regulated expression in lymphoid cells. Human and rodent L7 proteins carry sequences similar to the basic-region-leucine-zipper(BZIP)-motif of DNA-binding eucaryotic transcription factors. We show here that the region of L7 carrying the latter motif mediates L7-dimerization and stable binding to DNA and RNA. A preferential binding to RNA-structures is demonstrated.

Besides functional defects, different phenotypical alterations of lymphocytes have been described in patients with CVID. A decrease in LAM-1- (= Leu8) and CD21 expression was observed on B cells. Some patients with CVID show alterations in their T-cell subpopulations: The most striking features of this subgroup are low CD4/CD8-ratio, an increase in CD57/CD8 double-positive lymphocytes, and a strong enhancement of HLA-DR and "memory" markers such as CD29 and LFA-3 on T cells.

Five cases (3 men, 2 women) of late-onset variable immunodeficiency syndrome (CVID), characterized by similar clinical and immunological findings as well as histological demonstration of chronic granulomatous infection, are reported. All patients had frequent attacks of respiratory infections with recurrent bronchitis and pneumonia. In addition to predominating basally localized streaky-nodular lung changes all patients had hepatosplenomegaly and granulomatous infections of other organs. Immunologically, marked hypogammaglobulinaemia of all Ig classes, lymphopenia, and absence of terminal B-cell maturation were predominant. In-vitro tests under pokeweed-mitogen failed to demonstrate terminal plasma-cell differentiation of B-lymphocytes and thus Ig synthesis. Without pokeweed-mitogen there were largely nonsecretory B-blasts with abnormal granulated cytoplasmic Ig formation. Skin testing with Multitest application revealed almost complete anergy, both in the Arthus (24 h) and the late reactions (48 and 72 h). Nonetheless, T-cell reaction in-vitro was much less affected than B-cell function. "Natural killing" and antibody-dependent cytotoxicity were normal or slightly increased.

A limiting dilution system was established in order to estimate frequencies of interleukin-2 (IL-2)-responsive, autoreactive and alloreactive T cells in samples of peripheral blood (PBL) and synovial fluid lymphocytes (SFL), from patients with rheumatoid arthritis (RA) and lyme disease, as well as from healthy donors and a patient with osteoarthrosis. The frequencies of IL-2-dependent T-cell colony formation were significantly higher in patients with RA and lyme disease (median: 1/287) as compared to controls (median: 1/1,313) indicating a preactivation of T cells in these patients in vivo. Autoreactivity was measured by the proliferative response of T-cell lines to autologous irradiated PBL as stimulating cells. The frequencies of autoreactive T cells in blood were significantly higher in patients (median: 1/2,615) as compared to controls (median: 1/19,607). There was no significant difference in autoreactive T-cell frequencies between the patients' SFL (median: 1/3,185) and PBL (median: 1/2,615). In every case the frequency of alloreactive T cells exceeded the frequency of autoreactive T cells. Most autoreactive T-cell lines were also alloreactive and were shown to be MHC Class II-restricted. There is evidence of a down regulation of autoreactive T cells by suppressor cells in peripheral blood in two cases with elevated autoreactive T-cell frequencies (one RA patient and one control patient suffering from a viral infection). In contrast, no suppression of autoreactive T cells was observed in the RA patients' SFL or in PBL and SFL from patients with lyme disease. These results suggest that the chronic inflammation observed in RA and lyme disease may be supported by an elevated number of autoreactive T cells in the absence of suppressive mechanisms.

Epstein-Barr virus (EBV)-transformed human B lymphoblastoid cells share certain properties with monocytes: they are capable of presenting protein antigens to antigen-specific T-lymphocytes and of releasing an Interleukin 1-like factor. It was our interest to study whether transformed B-cells resemble monocytes by generating toxic oxygen radicals. Human B-cell lines were developed from human peripheral blood lymphocytes by EBV-transformation. The induction of the respiratory burst in the B-cells was assessed by chemiluminescence (CL) in the presence of lucigenin. B-cells were stimulated with phorbol-myristate-acetate (PMA), zymosan particles, the chemotactic peptide f-met-phe, the complement split product C5a and with a recently described granulocyte activating cytokine (GRAM). Stimulation with PMA elicited a distinct CL-response in the tested B-cell lines. The CL-signal was significantly reduced by superoxide dismutase, but not by D-mannitol and catalase. No significant response to any of the other stimuli was detected. Furthermore, none of the stimuli induced a luminol-enhanced CL signal, which, in contrast to lucigenin, is dependent on the presence of peroxidase. Our results indicate that EBV infected B-cells were able to generate significant amounts of reactive oxygen species, particularly superoxide. It appears that virus transformation uncovers genetic information which is usually not expressed in non-transformed B-cells.