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This report describes the project to identify the global distribution of extended HLA haplotypes, a component of 16th International HLA and Immunogenetics Workshop ( IHIW), and summarizes the initial analyses of data collected. The project aims to investigate extended HLA haplotypes, compare their distribution among different populations, assess their frequency in hematopoietic stem cell unrelated donor registries and initiate an international family studies database and DNA repository to be made publicly available. HLA haplotypes compiled in immunogenetics laboratories during the evaluation of transplant candidates and related potential donors were analysed. Haplotypes were determined using the pedigree analysis tool publicly available from the National Marrow Donor Program ( NMDP) website. Nineteen laboratories from 10 countries (11 laboratories from North America, five from Asia, two from Latin America and one from Australia) contributed data on a total of 1719 families comprised of 7474 individuals. We identified 10 393 HLA haplotypes, of which 1682 haplotypes included high-resolution typing at HLA- A, B, C, DRB1 and DQB1 loci. We also present haplotypes containing MICA and other HLA loci and haplotypes containing rare alleles seen in these families. The project will be extended through the 17th IHIW, and investigators interested in joining the project may communicate with the first author. [ABSTRACT FROM AUTHOR]

The human gastrointestinal tract, skin and mucosal surfaces are inhabited by a complex system of bacteria, viruses, fungi, archaea, protists, and eukaryotic parasites with predominance of bacteria and bacterial viruses (bacteriophages). Collectively these microbes form the microbiota of the microecosystem of humans. Recent advancement in technologies for nucleic acid isolation from various environmental samples, feces and body secretions and advancements in shotgun throughput massive parallel DNA and RNA sequencing along with 16S ribosomal gene sequencing have unraveled the identity of otherwise unknown microbial entities constituting the human microecosystem. The improved transcriptome analysis, technological developments in biochemical analytical methods and availability of complex bioinformatics tools have allowed us to begin to understand the metabolome of the microbiome and the biochemical pathways and potential signal transduction pathways in human cells in response to microbial infections and their products. Also, developments in human whole genome sequencing, targeted gene sequencing of histocompatibility genes and other immune response associated genes by Next Generation Sequencing (NGS) have allowed us to have a better conceptualization of immune responses, and alloimmune responses. These modern technologies have enabled us to dive into the intricate relationship between commensal symbiotic and pathogenic microbiome and immune system. For the most part, the commensal symbiotic microbiota helps to maintain normal immune homeostasis besides providing healthy nutrients, facilitating digestion, and protecting the skin, mucosal and intestinal barriers. However, changes in diets, administration of therapeutic agents like antibiotics, chemotherapeutic agents, immunosuppressants etc. along with certain host factors including human histocompatibility antigens may alter the microbial ecosystem balance by causing changes in microbial constituents, hierarchy of microbial species and even dysbiosis. Such alterations may cause immune dysregulation, breach of barrier protection and lead to immunopathogenesis rather than immune homeostasis. The effects of human microbiome on immunity, health and disease are currently under intense research with cutting edge technologies in molecular biology, biochemistry, and bioinformatics along with tremendous ability to characterize immune response at single cell level. This review will discuss the contemporary status on human microbiome immune system interactions and their potential effects on health, immune homeostasis and allograft transplantation., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.)

Background: Following second heart transplantation (HTx), some patients experience graft failure and require third-time heart transplantation. Little data exist to guide decision-making with regard to repeat retransplantation in older patients., Methods: We performed a retrospective cohort analysis of patients receiving a third HTx, as identified in the United Network for Organ Sharing (UNOS) database from 1985 to 2017., Results: The study cohort consisted of N = 60 patients, with an average age of 29 with a standard deviation of ±18 years. Overall survival for the cohort at 1, 5, and 10 years is 83%, 64%, and 44%, respectively. The rate of third-time HTxs has steadily increased in all age groups. Patients older than 50 years now account for 18.3% of all third-time HTxs. Although this group demonstrated longer average previous graft survival, after third HTx they demonstrate significantly poorer survival outcomes compared to third-time HTx recipients younger than 21 (P = 0.05). Age over 50, BMI over 30, and diabetes were all found to be independent risk factors for decreased survival following third HTx., Conclusions: We describe trends in patients undergoing third HTx. We highlight subsets of such recipients who exhibit decreased survival., (© 2019 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: This study explores the potential diagnostic utility of soluble Human Leukocyte Antigen (sHLA) molecules differentially released by lung adenocarcinoma and benign lung lesions., Methods: Conditioned media from the NSCLC cell lines H358 and H1703 were immunoblotted for soluble isoforms of major histocompatibility complex (MHC) class I (ABC) and II (DRB1, DMB, and DQ) antigens. Sera from 25 patients with benign and 25 patients with malignant lesions were similarly evaluated to appraise the potential diagnostic value., Results: Higher concentrations of soluble HLA class I molecules were observed in conditioned medium for the highly-invasive H1703 cell line, relative to the more indolent H358 cells. Evaluation of these markers against a cohort of 50 cases demonstrated that patients with malignant lesions possess higher levels of HLA class I and II molecules relative to those with benign lesions (p < 0.05), with exception to the primary isoform, DQA1, which was suppressed in malignancies. An analysis of biomarker performance via ROC analysis revealed promising performance (AUC > 0.75) for DMB and the 26 kDa isoform of DQ in distinguishing lesion pathology., Conclusions: Soluble HLA molecules may have diagnostic value for early-stage NSCLC. Validation studies are currently underway using sera from a lung cancer screening cohort., (Copyright © 2018. Published by Elsevier Inc.)

Introduction: Vimentin is an intermediate filament protein generally expressed in the cytosol of many adult cell types, including leukocytes, fibroblasts and endothelial cells. Several tissue and/or injury-specific isoforms of vimentin are known to exist that may trigger autoimmune responses due to aberrant structural or conformational variations. Such scenarios include allograft rejection and certain autoimmune diseases, such as rheumatoid arthritis. The primary objective for this study was to develop a Luminex immunobead assay to quantitate circulating levels of vimentin antibodies and, secondarily, to appraise the feasibility of these autoantibodies as a biomarker for clinical diagnosis., Methods: Recombinant human vimentin was conjugated to MagPlex® beads using standard carbodiimide/NHS chemistry and coupling efficiency tested and assay parameters determined using a commercial anti-vimentin polyclonal antibody. A limited number of serum samples (n=71) were then tested to evaluate the diagnostic value for future biomarker development efforts., Results: Findings from repeated testing of three distinct batches of assays provide assay range parameters of 0.18-15μg/mL, median inter-assay recovery parameter within 1% of completion, and inter-assay variation (%CV) at 7%. The assay was found to be stable at several conditions with less than 5% loss in a month. Preliminary evaluation of the assay demonstrates significantly (p=0.022) higher circulating levels of anti-vimentin antibodies in 51 cases of renal allograft rejection relative to 20 cases of age-matched controls., Conclusion: A direct capture assay for vimentin autoantibodies was developed and analytically validated. Preliminary evaluation of this assay against patient materials was promising and justifies additional testing with larger cohorts in future studies., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Bla g 2 is one of the most potent cockroach allergens. No effective treatment or vaccination strategies are yet available. We evaluated the prophylactic efficacy of Bla g 2 DNA vaccination in a mouse model of allergic airway inflammation. C57/BL6 mice were given Bla g 2 DNA vaccine prior to sensitization with recombinant Bla g 2 (rBla g 2) antigens, followed by nebulized rBla g 2 challenge. Bla g 2 vaccine could express at both transcriptional and translational levels in mammalian cells. Moreover, Bla g 2 vaccine significantly reduced the total inflammatory cell infiltrate and eosinophilia in bronchoalveolar lavage fluid, and markedly decreased allergen-induced inflammatory infiltrates in the lungs and Bla g 2-specific IgE in serum upon challenge with rBla g 2. Importantly, Bla g 2 vaccine could induce the production of antigen-specific IFN-γ and downregulated Th2 pro-inflammatory cytokines IL-4, IL-5, and IL-13. Thus, DNA vaccination showed protective efficacy against a clinically relevant allergen, Bla g 2., (Copyright © 2012. Published by Elsevier Inc.)

Autoimmune inner ear disease is described as progressive, bilateral although asymmetric, sensorineural hearing loss and can be improved by immunosuppressive therapy. We showed that the inner ear autoantigen β-tubulin is capable of inducing experimental autoimmune hearing loss (EAHL) in mice. Immunization of BALB/c mice with β-tubulin resulted in hair cell loss and hearing loss, effects that were not seen in animals immunized with control peptide. Moreover, the EAHL model showed that β-tubulin responsiveness involved CD4(+) T cells producing IFN-γ, and T cell mediation of EAHL was determined by significantly increased auditory brainstem response after adoptive transfer of β-tubulin-activated CD4(+) T cells into naive BALB/c recipients. The potential mechanisms responsible for the observed pathology of EAHL can be attributed to decreased frequency and impaired suppressive function of regulatory T cells. Our study suggests that EAHL may be a T cell-mediated organ-specific autoimmune disorder of the inner ear., (Published by Elsevier Inc.)

The effect of IL-1beta on Staphylococcus aureus was investigated in terms of mRNA expression profile of bicomponent leukotoxins (Luk ED, Luk PV, HlgA, and HlgCB) as well as microbial surface components recognizing adhesive matrix molecules (MSCRAMMs). Upon exposure to higher concentrations of IL-1beta, S. aureus expressed significantly higher levels of MSCRAMMs mRNA [fibronectin-binding protein (FnBp), fibrinogen-binding protein or clumping factor (Clf), and collagen-binding protein (Cna)] and had significantly lower expression of mRNAs for bicomponent leukotoxins. Sequential in vitro passing of S. aureus in the absence of rhIL-1beta resulted in reduced binding to rhIL-1beta resulted in lack of significant changes in virulence gene expression upon exposure to low or high concentrations of rhIL-1beta. It is possible that IL-1beta modulates the pathogenic potential of S. aureus by altering its virulence gene expression to adapt to the host's inflammatory micromilieu. The ability to express higher levels of MSCRAMMs and low levels of leukotoxins might contribute towards the successful invasion and persistence of S. aureus in chronic inflammatory conditions. Determination of the mechanisms of IL-1-induced alterations in S. aureus gene expression may lead to the identification of novel therapeutic targets against this ever-evolving opportunistic pathogen.

Intracellular IL-1 receptor antagonist (icIL-1ra) is reportedly involved in functions independent of blocking IL-1 receptor signaling. Fibroblasts derived from the involved skin of patients with systemic sclerosis (SSc) are predominantly of the myofibroblast phenotype, with higher levels of icIL-1ra compared to normal skin fibroblasts. We examined the effect of overexpression of icIL-1ra on the phenotype and function of normal fibroblasts with respect to the expression of alpha smooth muscle actin (alpha-SMA), a specific marker for myofibroblasts, and plasminogen activator inhibitor (PAI), a protein involved in fibrogenesis and expressed at higher levels in myofibroblasts, and the production of collagenase (matrix metalloproteinase-1 (MMP-1)), the major enzyme involved in the degradation of native collagen in the skin. Normal human foreskin fibroblasts overexpressing icIL-1ra showed higher levels of alpha-SMA and PAI and had lower levels of collagenase and MMP-1 mRNA induced by inflammatory cytokines. By contrast, levels of mRNA for tissue inhibitor of metalloproteinase-1 in the transfected cells were not different from the control cells. Pretreatment of the ic-IL-1ra-transfected cells with antisense oligonucleotide directed against the mRNA of icIL-1ra restored MMP-1 expression induced by stimulation with IL-1beta. Our data indicate novel functions for icIL-1ra, which might be relevant to the genesis of fibrotic diseases such as SSc.

Infections of body tissue by Staphylococcus aureus are quickly followed by degradation of connective tissue. Patients with rheumatoid arthritis are more prone to S. aureus-mediated septic arthritis. Various types of collagen form the major structural matrix of different connective tissues of the body. These different collagens are degraded by specific matrix metalloproteinases (MMPs) produced by fibroblasts, other connective tissue cells, and inflammatory cells that are induced by interleukin-1 (IL-1) and tumor necrosis factor (TNF). To determine the host's contribution in the joint destruction of S. aureus-mediated septic arthritis, we analyzed the MMP expression profile in human dermal and synovial fibroblasts upon exposure to culture supernatant and whole cell lysates of S. aureus. Human dermal and synovial fibroblasts treated with cell lysate and filtered culture supernatants had significantly enhanced expression of MMP-1, MMP-2, MMP-3, MMP-7, MMP-10, and MMP-11 compared with the untreated controls (p < 0.05). In the S. aureus culture supernatant, the MMP induction activity was identified to be within the molecular-weight range of 30 to >50 kDa. The MMP expression profile was similar in fibroblasts exposed to a combination of IL-1/TNF. mRNA levels of several genes of the mitogen-activated protein kinase (MAPK) signal transduction pathway were significantly elevated in fibroblasts treated with S. aureus cell lysate and culture supernatant. Also, tyrosine phosphorylation was significantly higher in fibroblasts treated with S. aureus components. Tyrosine phosphorylation and MAPK gene expression patterns were similar in fibroblasts treated with a combination of IL-1/TNF and S. aureus. Mutants lacking staphylococcal accessory regulator (Sar) and accessory gene regulator (Agr), which cause significantly less severe septic arthritis in murine models, were able to induce expression of several MMP mRNA comparable with that of their isogenic parent strain but induced notably higher levels of tissue inhibitors of metalloproteinases (TIMPs). To our knowledge, this is the first report of induction of multiple MMP/TIMP expression from human dermal and synovial fibroblasts upon S. aureus treatment. We propose that host-derived MMPs contribute to the progressive joint destruction observed in S. aureus-mediated septic arthritis.

Aminobisphosphonates are drugs used in the treatment of hypercalcemia, Paget's disease, osteoporosis, and malignancy. Some patients treated with aminobisphosphonates have a transient febrile reaction that may be caused by an increased serum concentration of proinflammatory cytokines. Aminobisphosphonates induce the production of certain proinflammatory cytokines in vitro, especially in cells of monocytic lineage. A unique feature of aminobisphosphonates is that they bind the Vgamma2Vdelta2 class of T cells, which are found only in primates, and stimulate cytokine production. The effects of aminobisphosphonates on other cells, including macrophages, are incompletely understood. We show in this study that treatment of murine macrophages with pamidronate, a second generation aminobisphosphonate, induces TNF-alpha production. Furthermore, pretreatment of murine macrophages with pamidronate before stimulation with IFN-gamma significantly augments IFN-gamma-dependent production of TNF-alpha. This pamidronate-mediated augmentation of TNF-alpha production results in sustained phosphorylation of the tyrosine residue at position 701 of STAT1 after IFN-gamma treatment. Our data suggest that this sustained phosphorylation results from inhibition of protein tyrosine phosphatase activity. We also show that pamidronate treatment increases TNF-alpha production in vivo in mice. Pamidronate-augmented TNF-alpha production by macrophages might be a useful strategy for cytokine-based anticancer therapy.

Purpose of Review: There is an intense interest in the potential of circulating blood cells and epithelium-related nonfibroblast cells to change into matrix synthesizing fibroblasts and myofibroblasts. These sources of fibroblasts may have importance in systemic sclerosis (scleroderma)., Recent Findings: Epithelial cells from different sources can transition into fibroblasts and myofibroblasts in response to transforming growth factor beta and other growth factors/cytokines. This is called epithelial-mesenchymal transition (EMT). EMT has been repeatedly demonstrated to occur in several models of renal fibrosis including lupus prone mice. Quite unexpectedly, bone morphogenic protein 7 prevents EMT and protects lupus mice and other renal fibrosis models from developing fibrosis in the kidneys. Human peripheral blood mononuclear cells under different conditions of culture give rise to several different types of fibroblast-like cells. In SSc, it has been observed that the sera have low levels of serum amyloid protein. Serum amyloid protein has been found to inhibit the generation of fibrocytes from CD14 precursors. The implications of these potential sources of fibroblasts and myofibroblasts in systemic sclerosis and related rheumatic diseases are discussed., Summary: Fibroblasts and myofibroblasts in skin and internal organs of patients with systemic sclerosis and related diseases may possibly arise not only from the resident fibroblast population but from epithelial cells, pericytes, monocytes, and other progenitors from the circulating pool of hematopoietic cells and stem cells. These alternative sources of fibroblasts would best be treated by specifically targeting the transition or transdifferentiation process by which cells change into fibroblasts.

Clinical studies have shown positive associations among sustained and intense inflammatory responses and the incidence of bacterial infections. Patients presenting with acute respiratory distress syndrome (ARDS) and high levels of proinflammatory cytokines, such as tumor necrosis factor alpha (TNF-alpha), interleukin 1 beta (IL-1 beta), and IL-6, have increased risk for developing nosocomial infections attributable to organisms such as Staphylococcus aureus, Pseudomonas aeruginosa, and Acinetobacter spp., compared to those patients with lower levels. Our previous in vitro studies have demonstrated that these bacterial strains exhibit enhanced growth extracellularly when supplemented with high concentrations of pure recombinant TNF-alpha, IL-1 beta, or IL-6. In addition, we have shown that the intracellular milieu of phagocytic cells that are exposed to supraoptimal concentrations of TNF-alpha, IL-1 beta, and IL-6 or lipopolysaccharide (LPS) favors survival and replication of ingested bacteria. Therefore, we hypothesized that under conditions of intense inflammation the host's micromilieu favors bacterial infections by exposing phagocytic cells to protracted high levels of inflammatory cytokines. Our clinical studies have shown that methylprednisolone is capable of reducing the levels of TNF-alpha, IL-1 beta, and IL-6 in ARDS patients. Hence, we designed a series of in vitro experiments to test whether human monocytic cells (U937 cells) that are activated with high concentrations of LPS, which upregulate the release of proinflammatory cytokines from these phagocytic cells, would effectively kill or restrict bacterial survival and replication after exposure to methylprednisolone. Fresh isolates of S. aureus, P. aeruginosa, and Acinetobacter were used in our studies. Our results indicate that, compared with the control, stimulation of U937 cells with 100-ng/ml, 1.0-microg/ml, 5.0-microg/ml, or 10.0-microg/ml concentrations of LPS enhanced the intracellular survival and replication of all three species of bacteria significantly (for all, P = 0.0001). Stimulation with < or =10.0 ng of LPS generally resulted in efficient killing of the ingested bacteria. Interestingly, when exposed to graded concentrations of methylprednisolone, U937 cells that had been stimulated with 10.0 microg of LPS were able to suppress bacterial replication efficiently in a concentration-dependent manner. Significant reduction in numbers of CFU was observed at > or =150 microg of methylprednisolone per ml (P values were 0.032, 0.008, and 0.009 for S. aureus, P. aeruginosa, and Acinetobacter, respectively). We have also shown that steady-state mRNA levels of TNF-alpha, IL-1 beta, and IL-6 in LPS-activated cells were reduced by treatment of such cells with methylprednisolone, in a concentration-dependent manner. The effective dose of methylprednisolone was 175 mg, a value that appeared to be independent of priming level of LPS and type of mRNA. We therefore postulate that a U-shaped relationship exists between the level of expression of TNF-alpha, IL-1 beta, and IL-6 within the phagocytic cells and their abilities to suppress active survival and replication of phagocytized bacteria.

Replication of Staphylococcus aureus is significantly enhanced in the presence of recombinant interleukin (IL)-1beta. In this study, specific binding of IL-1beta to the surface of S. aureus significantly increased growth of S. aureus in the presence of IL-1beta and IL-1ra in a concentration-dependent manner. Although IL-1ra enhanced the growth of S. aureus, there was a significant reduction in IL-1beta-mediated growth enhancement of S. aureus when 25-fold excess amounts of IL-1ra (in comparison with the IL-1beta concentration) were present in the culture medium. Thus, IL-1beta may influence the growth of S. aureus through a receptor-mediated event. By using 5 linear peptides spanning limited regions of IL-1beta, the growth-promoting regions were localized to amino acid residues 118-147 and 208-240. These results build on the newly evolved concept of direct interactions between the soluble mediators of inflammation and infectious agents.

We have previously reported that in acute respiratory distress syndrome (ARDS), nonsurvivors have persistent elevation in pulmonary and circulating proinflammatory cytokine levels over time and a high rate of nosocomial infections antemortem. In these patients, none of the proven or suspected nosocomial infections caused a transient or sustained increase in plasma proinflammatory cytokine levels above preinfection values. We hypothesized that cytokines secreted by the host during ARDS may favor the growth of bacteria. We conducted an in vitro study of the growth of three bacteria clinically relevant in nosocomial infections, evaluating their in vitro response to various concentrations of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, and IL-6. We found that all three bacterial species showed concentration-dependent growth enhancement when incubated with one or more tested cytokines and that blockade by specific neutralizing cytokine MoAb significantly inhibited cytokine-induced growth. When compared with control, the 6-h growth response (cfu/ml) was maximal with IL-1beta at 1,000 pg for Staphylococcus aureus (36 +/- 16 versus 377 +/- 16; p = 0.0001) and Acinetobacter spp. (317 +/- 1,147 versus 1,124 +/- 147; p = 0.002) and with IL-6 at 1,000 pg for Pseudomonas aeruginosa (99 +/- 50 versus 509 +/- 50; p = 0.009). The effects of cytokines were seen only with fresh isolates and were lost with passage in vitro on bacteriologic medium without added cytokines. In this study we provide additional evidence for a newly described pathogenetic mechanism for bacterial proliferation in the presence of exaggerated and protracted inflammation.

Herpes simplex virus infection of the eye can result in a blinding inflammatory lesion that is a T cell mediated immunopathological reaction. A prominent early event following HSV infection is neutrophil invasion of the corneal stroma. These cells may be involved in viral clearance and may influence the nature of the anti HSV T cell response which subsequently occurs. This article measures the expression of some key molecules which could participate in viral clearance and immune modulation. Using RT-PCR and in-situ hybridization, both corneal and peritoneal neutrophils were shown to be sources of iNOS and TNF alpha molecules which likely contribute to antiviral activity. Neutrophils also produce the cytokine IL-12, a key molecule which modulates the CD4+ T cell response to a type which mediates immunopathology. The present results indicate that neutrophils play an important role in the pathogenesis of herpetic ocular lesions.

To test the principle that genetically engineered epitopes in a plasmid DNA can efficiently induce specific immunity, a minigene cassette encoding cytotoxic T lymphocyte (CTL), helper T and B cell epitopes from herpes simplex virus (HSV) was constructed and placed in an expression vector named pcMini. Following immunizations with pcMini, mice developed epitope-specific CTLs comparable to the response induced by live HSV. Less effective but detectable antibody, lymphoproliferation, and T cell cytokine responses were also produced. In addition, pcMini-primed mice elicited a recall response upon restimulation with recombinant vaccinia virus expressing HSV antigen. The protection provided by minigene vaccination was significant, although not as efficient as live virus vaccine. The DNA minigene approach may prove useful to define and induce immune responses against minimal antigenic determinants.

Immunization with plasmid DNA encoding various proteins promises to be a valuable vaccine approach especially if its immunogenicity could be optimized. In this study we show that the intramuscular delivery in dendritic cells (DC) of naked plasmid DNA encoding two proteins of herpes simplex virus (HSV) leads to the induction of significantly enhanced levels of resistance to viral challenge. Whereas DC transfected in vitro with DNA induced enhanced immunity, similarly transfected macrophage (M phi) populations lacked immunogenicity even though plasmid expression occurred in vitro. The enhanced immunity induced by DC-delivered DNA appeared to be associated mainly with an increased Th1 CD4+ T cell response. Our results add evidence that DC are the essential antigen-presenting cell types involved in immune responses to intramuscularly administered DNA vaccines.

The use of attenuated Salmonella vaccine vectors as delivery vehicles for heterologous antigens has been extensive. The majority of work has analyzed the specific immune responses to the recombinant antigen in question. In addition, most analysis has been performed on animals maintained with sterile food, water, and bedding. This report defines the Salmonella specific cytokine responses in the gut associated lymphoid tissue after oral immunization with two highly publicized attenuated Salmonella carrier strains in animals maintained with nonsterile food, water, and bedding. Increases in expression of both IL-4 and IFN-gamma occur following immunization with either Salmonella construct. In addition, other cytokines (IL-6, IL-7, IL-12) increase at similar levels in either BRD509 or KR1 dosed animals. Proinflammatory cytokines IL-1 and TNF-alpha are also present but unchanged at early time points (6, 24, and 72 hours), increasing only after 7 days postimmunization. These data have implications in the generation of immunity to recombinant antigens since the response to Salmonella will dictate the direction of responses in terms of CD4 T cell activation.

Herpetic stromal keratitis (HSK) has an immunopathological basis, thought primarily to involve a CD4+ T cell-mediated immune response to viral antigen. Other cell types, however, particularly those involved in nonspecific immunity, such as natural killer (NK) cells or neutrophils, may also contribute to tissue destruction in the cornea. The reconstituted SCID mouse model of HSK provides a powerful system in which to study the interactions of the innate and adaptive immune responses to herpes simplex virus type 1 corneal infection. In the present study, reconstituted SCID mice depleted of NK cells had a reduced incidence and severity of clinical and histopathological HSK. The levels of T cell cytokine protein and message in restimulated splenocytes and cytokine message in corneas did not differ between experimental groups. However, significantly fewer neutrophils were seen within the inflamed corneas of NK-depleted SCID mice. Therefore, endogenous NK cells may indirectly influence the severity of HSK in reconstituted SCID mice by affecting neutrophil migration into the cornea.

Pathological effects of herpes simplex virus (HSV) can result due to a combination of direct viropathic effects and immunological reactions to viral antigens. The immunological reactions are orchestrated by a variety of cytokines and chemokines released by the host cells. Therefore, the cytokine gene expression in response to HSV-1 infection in a permissive murine cell line was investigated. The data demonstrate that HSV-1 induced a selective activation of IL-6 gene expression at the mRNA and protein levels, in the permissive cell line. The cell line used was capable of expressing IL-1, IL-7, and IL-10 in addition to IL-6, upon lipopolysaccharide stimulation. UV or heat-inactivated viruses were unable to upregulate IL-6 expression. However, mutant HSV-1 strains lacking fully functional ICP0, ICP4, ICP8, or ICP27 genes, thereby rendering them replication incompetent or impaired in in vitro cell growth (ICP0), enhanced IL-6 expression selectively. Considering the role of IL-6 in inflammation, immune response, and its known association with increased levels of MyD116 and GADD 34 mRNAs (genes involved in the prevention of apoptotic death of cells), the present data may have relevance to HSV-1-mediated diseases as well as to the prevalence of HSV-1 in the host.

The murine X-linked lymphoproliferative disease scurfy is similar to the Wiskott-Aldrich syndrome in humans. Disease in scurfy (sf) mice is mediated by CD4+ T cells. Based on similarities in scurfy mice and transgenic mice that overexpress specific cytokine genes, we evaluated the expression of cytokines in the lesions of sf mice by Northern blotting, quantitative reverse-transcription polymerase chain reaction (RT-PCR) and by hybridization in situ. Overall, the phenotypic characteristics of scurfy disease correlated well with increased interleukin (IL)-4 (lymphadenopathy), IL-6 (B cell proliferation, hypergammaglobulinemia), IL-7 (dermal inflammatory cell infiltration), and high levels of tumor necrosis factor-alpha (wasting).

Among antigen-presenting cells dendritic cells (DC) have the unique ability to generate primary T cell response. The reasons for the superior inductive property of DC still remain obscure. The explanations offered include higher expression of CD80, MHCII, and ICAMI on DC surface which allows effective cluster formation with T cells. It is also possible that additional cellular characteristics of DC, i.e., their ability to release critical mediators involved in the induction of effective immune response, are important. We examined the ability of DC to express IL-1, IL-6, and IL-12 using the highly sensitive reverse transcription-quantitative polymerase chain reaction. Our data show that highly purified (97-99% pure) murine splenic DC were capable of expressing IL-1, IL-6 and IL-12 mRNA upon stimulation with lipopolysaccharide. We also compared the ability of DC and macrophages to induce T cell-derived cytokines IL-2 and IFN-gamma in an in vitro antigen-specific costimulation assay. In naive T cells stimulated with antigen presented via DC or macrophages, the levels of mRNA for IL-2 and IFN-gamma were 2- to 4-fold higher when cells were stimulated with DC. Overall, our data add additional support to the description of DC as superior antigen-presenting cells for the activation of naive T cells.

A new human monoclonal plasma cell line, designated UTMC-2, was established from the pleural effusion of a patient with immunoglobulin (Ig)A kappa-related multiple myeloma. The cultured cells were Epstein-Barr virus-negative and exhibited the morphological and ultrastructural features characteristic of plasma cells. Immunohistochemical analyses revealed the presence of cytoplasmic IgA kappa as well as the plasma cell-associated surface antigens CD38 and CD56. Other B-cell markers, including CD10, CD19, CD20, and HLA-DR, were absent. The UTMC-2 cells were interleukin (IL)-6 responsive: Co-culture with IL-6 increased IgA kappa synthesis and cell proliferation in a dose-dependent manner. In contrast, an IL-6 antisense oligonucleotide had an opposite effect. Although the UTMC-2 cells expressed IL-6 mRNA (as demonstrated by reverse transcriptase-polymerase chain reaction (RT-PCR)) and contained IL-6, the concentration of this cytokine in cell culture supernatants was less than that detectable by the enzyme-linked immunosorbent assay (ELISA) employed (i.e. <3 pg/ml). Further, cell growth was not inhibited by polyclonal or monoclonal anti-IL-6 antibodies. Flow cytometric analysis revealed that IL-6 receptors present on the surface of the UTMC-2 cells were not saturated with endogenous IL-6. Taken together, these results indicate that, in this human plasma cell line, IL-6 functions uniquely in an intracellular autocrine fashion to enhance Ig synthesis and cell growth. In this respect, the UTMC-2 cells represent a novel resource for further study of the role of IL-6 in the pathogenesis of multiple myeloma.