Expression of the 60 kDa heat shock protein in normal and inflamed liver.

The 60 kDa heat shock proteins (HSP 60) have been well conserved throughout evolution and are highly immunogenic. Cross-reactivity between bacterial and mammalian HSP 60 is considered a likely mechanism in the pathogenesis of autoimmune diseases. T cell and B cell reactivity to HSP 60 is found in patients with rheumatoid or juvenile arthritis, and the expression of HSP 60 in the inflamed joint is found to be increased. In this study the presence of HSP 60 was demonstrated in normal and inflamed lives. HSP 60 was found to be predominantly expressed in hepatocytes and Kupffer cells, and mainly localized in mitochondria. Heat stress in the form of a 1 h incubation at 42 degrees C increased HSP…

Epstein Barr virus-transformed lymphocytes of patients with Wegener's granulomatosis produce antibodies against the cytoplasm of human neutrophil granulocytes (ANCA)

Zytokine in der Ätiopathogenese der chronischen Polyarthritis — Neue Therapienansätze

Grundsatzlich last sich in der Synovialmembran chronischer Polyarthritiker nur ein beschranktes Zytokinprofil nachweisen: Wahrend T-Lymphozytenprodukte wie IL-2, IL-3, IL-4, IFN-gamma und TNF-beta nur sparlich vorhanden sind, finden sich exzessive Mengen von Makrophagen/Fibroblastenprodukten wie IL-1, IL-6, IL-8, TNF-alpha und M-CSF [1, 2]. Auf IL-6 und IL-8, zwei wichtige proinflammatorische und erst neuerdings genauer charakterisierte Zytokine aus Makrophagen und Fibroblasten und deren Funktion bei der Amplifikation und Perpetuierung der chronischen Synovitis, soll hier naher eingegangen werden. IL-6 ist ein 26-kd Protein, welches von Monozyten, T-Lymphozyten und Fibroblasten produziert w…

Tubulointerstitielle-Nephritis-Uveitis-Syndrom (TINU-Syndrom)

Abstract For 10 weeks a 25-year-old man had been suffering from tiredness, fatigue, nausea and a 16 kg weight loss. Erythrocyte sedimentation rate (83/133 mm), serum C-reactive protein (5.5 mg/dl) and creatinine (5.05 mg/dl) were all elevated. He also had proteinuria (1120 mg daily), sterile leukocytosis and a creatinine clearance of 10 ml/min. Renal biopsy showed interstitial nephritis and bone marrow biopsy revealed non-caseous epithelioid-cell granulomas. 14 days after admission he developed acute iritis in the right eye. Other causes having been excluded, the diagnosis of tubulo-intestinal nephritis with uveitis (TINU syndrome) was made. The clinical symptoms and laboratory findings imp…

In Vitro Interactions of C-ANCA (Antibodies to Proteinase 3) with Human Endothelial Cells

Several concepts concerning the pathogenicity of antineutrophil cytoplasmic antibodies (ANCA) exist, but till now only sparse data about ANCA-endothelial interactions are available. In this study we have investigated the expression of proteinase 3 (PR-3) in human umbilical endothelial cells (HEC) using purified anti-PR3 antibodies (C-ANCA) of patients with Wegener’s granulomatosis (WG) and monoclonal antibodies to PR-3 (human and murine) as probes. Performing cytoELISAs, laser scanning microscopy and Western blot we were able to show that treatment of HEC with IL-1-alpha led to an increased PR-3 expression in the cytoplasm and to a transient translocation into the EC-membrane. Representing …

A human renal cancer line as a new antigen source for the detection of antibodies to cytoplasmic and nuclear antigens in sera of patients with Wegener's granulomatosis.

Autoantibodies directed against cytoplasmic antigens of neutrophils (ANCA), especially proteinase 3 (C-ANCA), have proved to be a useful clinical tool to support the diagnosis or to monitor disease activity in Wegener's granulomatosis (WG). Till now, human neutrophil granulocytes have represented the major antigen source used to detect antibodies in WG by the immunofluorescence technique (IFT). We have tested serum samples of 164 patients with different connective tissue diseases (50 suffering from clinically active WG) performing IFT on a human renal cancer line (SK-RC11) and have found antibodies against the nuclear and cytoplasmic antigens in 39 patients. C-ANCA+ sera displayed a charact…

T cells involved in psoriasis vulgaris belong to the Th1 subset

Although the pathogenesis of psoriasis vulgaris is still unknown, several characteristics point to an immunologically mediated process. Epidermal psoriatic lesions are characterized by a hyperproliferation of keratinocytes and an infiltration of T lymphocytes and granulocytes. Because the former may be mediated in part by lymphokines secreted by T cells, we have focused our interest on the in vivo and in vitro cytokine secretion patterns of T lymphocytes from psoriatic lesions. In five patients T lymphocytes were obtained from epidermal specimens. The cells were propagated with lectin and irradiated feeder cells and subsequently cloned by limiting dilution. The resulting T-cell clones were …

Multiple osteoartikuläre Komplikationen (dialyse-assoziierte Spondarthropathie) und Karpaltunnelsyndrom bei chronischer Hämodialyse

Abstract During a nine-year treatment by haemodialysis for renal failure a now 57-year-old woman developed multiple complications of the skeletal system. Acute calcific periarthritis of the right shoulder became manifest one year after the start of the haemodialysis, followed the next years by progressive arthropathy with subchondral amyloid cysts of both shoulders, effusions in the knee-joint and destructive spondylarthropathy of the middle vertebrae. Carpal-tunnel syndrome also occurred, caused by a beta 2-microglobulin amyloidosis (beta 2-microglobulin concentration in serum 42.6 ng/l) and an aluminium osteopathy. These multiple complications, observed here in one patient, are each of th…

Thymoma and pure red cell aplasia in a patient with systemic lupus erythematosus.

We present the case of a female patient with a diagnosis of systemic lupus erythematosus (SLE) at the age of 54 years. At the age of 63 years, she suffered from malignant thymoma and 3 years after removal of the thymoma a diagnosis of pure red cell aplasia (PRCA) was established. This is, to our knowledge, the first report of the occurrence of SLE, thymoma and PRCA in the same patient. The case is discussed with regard to the already known associations between these diseases.

Antibodies to cytoskeletal proteins in patients with Crohn's disease

. The immunologic basis of inflammatory bowel disease has been the focus of interest of a series of studies on Crohn's disease and the process of immune sensitization at the gastrointestinal mucosal level is functionally poorly understood. To date only few contradictory reports concerning the incidence of autoantibodies in patients with this disease exist. The aim of this study was to investigate the sera drawn from 60 patients suffering from biopsy-proven Crohn's disease to evaluate the prevalence of autoantibodies against nuclear antigens and cytoskeletal proteins. Using standard methods, no anti-nuclear antibodies or antibodies to extractable nuclear antigens could be detected. All sera …

In vitro production of anti-neutrophilocyte-cytoplasm-antibodies (ANCA) by Epstein-Barr virus-transformed B-cell lines in Wegener's granulomatosis.

The frequent detection of anti-neutrophilocyte-cytoplasm-antibodies (ANCA) in patients with Wegener's granulomatosis (WG) led to the supposition that this disease might be of autoimmune nature. For some authors assume that Epstein-Barr virus (EBV) infection of human B-lymphocytes besides polyclonal activation could reveal the cryptic immune status against different autoantigens in patients with autoimmune diseases we investigated EBV-transformed B-lymphocytes from patients with Sjögren's syndrome, mixed connective tissue disease, WG and healthy blood donors. Two stable B-cell lines (Ho3, We1) could be established. Inhibition experiments showed that antibodies produced by transformed B-lymph…

Remission of severe rheumatoid arthritis following liver transplantation.

We present the case of a 32-year-old male who suffered from severe RA from the age of 21 years. After 9 years of active disease and poor response to therapy the patient developed severe hepatitis induced by the NSAID pirprofen. He went into fulminant hepatic failure necessitating emergency liver transplantation. Liver transplantation was followed by clinical and laboratory remission of his RA and he has remained virtually asymptomatic for more than 3.5 years. The possibility that this favourable clinical course was due to the immunosuppressive effect of the liver transplant rather than the ensuing immunosuppressive therapy is discussed.

HLA-B27-restricted CD8 T cells derived from synovial fluids of patients with reactive arthritis and ankylosing spondylitis.

Ankylosing spondylitis and seronegative spondylarthropathies such as Reiter's syndrome and reactive arthritis are strongly associated with HLA-B27. However, the mechanisms by which HLA-B27 is involved in disease susceptibility and pathogenesis are unknown. If the disease association is a consequence of HLA-B27's physiological function in antigen presentation, the disease should be mediated by cytotoxic T lymphocytes (CTLs) that recognise bacterial or self peptides presented by HLA-B27. Proof of this arthritogenic peptide model requires isolation of B27-restricted CD8 T cells from arthritic joints of patients with spondylarthropathies. An important question is whether "arthritogenic" bacteri…

Tolerance exists towards resident intestinal flora but is broken in active inflammatory bowel disease (IBD)

SUMMARY Hyporesponsiveness to a universe of bacterial and dietary antigens from the gut lumen is a hallmark of the intestinal immune system. Since hyperresponsiveness against these antigens might be associated with inflammation, we studied the immune response to the indigenous intestinal microflora in peripheral blood, inflamed and non-inflamed human intestine. Lamina propria monocuclear cells (LPMC) isolated from inflamed intestine but not peripheral blood mononuclear cells (PBMC) of IBD patients with active inflammatory disease strongly proliferated after co-culture with sonicates of bacteria from autologous intestine (BsA), Proliferation was inhibitable by anti-MHC class II MoAb, suggest…

klebsiella pneumoniae-reactive t cells in blood and synovial fluid of patients with ankylosing spondylitis comparison with hla–b27 + healthy control subjects in a limiting dilution study and determination of the specificity of synovial fluid t cell clones

Objective To study the frequency of Klebsiella pneumoniae-responsive T cells in the peripheral blood (PB) of ankylosing spondylitis (AS) patients compared with that in healthy HLA-B27+ donors, and to examine T lymphocyte clones (TLC) derived from AS patient synovial fluid (SF) for the presence of Klebsiella reactivity. Methods Limiting dilution analysis of PB T cells in 8 patients with active AS and in 8 HLA-B27+ healthy subjects was used to determine the frequency of PB T cells responsive to K pneumoniae and Escherichia coli GroEL. SF T cells from a patient with active AS were cloned, and 125 TLC were characterized in proliferation assays. Results There were fewer T cells in the PB of AS p…

Antibodies to Cathepsin G in Crohn's disease

. Antibodies directed against antigens in human neutrophils have proved to be of great diagnostic value in certain systemic vasculitides. Recent reports have focused the attention on these antigens as targets of antibodies in sera of patients with inflammatory bowel disease. We investigated the sera drawn from 60 patients suffering from biopsy proven Crohn's disease and 15 patients with active ulcerative colitis. Using sensitive enzyme-linked immunosorbent assays with purified antigens and Western blotting the following antibodies could be demonstrated: cathepsin G (cat-G) antibodies IgG 38.3%, IgM 13.3%, IgA 23.3% and antibodies against human leucocyte elastase (HLE) IgG, IgA, IgM 3.3%. Lo…

Role of bacteria-specific T cells in the immunopathogenesis of reactive arthritis.

Reactive arthritis is a usually self-limited sterile inflammation of joints that follows certain bacterial gastrointestinal or urogenital infections. The immunopathogenesis involves CD4+ T cells, which mediate an antigen-specific TH1 response to bacterial constituents within the joint. Properties of the arthritogenic bacteria and the physicochemical characteristics of the bacterial antigens may contribute to the development of reactive arthritis.

Reactivity of infiltrating T lymphocytes with microbial antigens in Crohn's disease.

Intestinal T lymphocytes are normally unresponsive to microbial and recall antigens in vitro, whereas the same antigens induce strong immune responses in peripheral-blood-derived T cells. We obtained T lymphocytes from peripheral blood and from the non-inflamed and inflamed intestinal mucosa of 6 patients (3 male, 3 female; mean age 33 years) with Crohn's disease. The T cells were stimulated in vitro with a range of microbial antigens. Whereas T cells from normal mucosa were unresponsive, those from inflamed mucosa had a proliferative response comparable to that of the peripheral-blood-derived T cells. These findings suggest that physiologic unresponsiveness to luminal antigens is abrogated…

Differential effects of IL-10 on proliferation and cytokine production of human gamma/delta and alpha/beta T cells.

Gamma/delta TCR bearing T lymphocytes represent a T-cell subset whose functional relevance remains unclear. Nevertheless these T cells may play a role in the early immune response against bacteria. Until now the regulatory mechanisms on this response have not been investigated. The study described here evaluated the immunoregulatory effects of Interleukin-10 on gamma/delta and alpha/beta TCR-positive T-cell clones and freshly isolated peripheral-blood mononuclear cells (PBMC). IL-10 has been shown previously to inhibit lectin and antigen-induced proliferation and cytokine production by alpha/beta T cells. The results outlined below show that rhIL-10 strongly inhibits lectin-induced producti…

Pneumatoceles and pneumothoraces complicating staphylococcal pneumonia: treatment by synchronous independent lung ventilation.

A 54 year old man with a staphylococcal sepsis developed staphylococcal pneumonia complicated by multiple pneumatoceles and bilateral tension pneumothoraces caused by bronchopleural fistulae. Excessive enlargement of the right sided pneumatoceles and a tension pneumothorax not improved by drainage led to mediastinal shift and compression of the right lung. Reversal of the mediastinal shift and closure of the bronchopleural fistulae was achieved by assisted independent lung ventilation.

MHC-unrestricted recognition of bacteria-infected target cells by human CD8+ cytotoxic T lymphocytes.

Abstract A CD8 + αβTCR + T cell clone (A35) was isolated from the synovial fluid of a patient with postenteric reactive arthritis caused by Yersinia enterocolitica . This clone efficiently killed autologous and allogeneic target cells that had been preincubated with live but not with heat-killed bacteria. There was no restriction by polymorphic parts of HLA-A, -B. or -C molecules and a HLA class II-deficient mutant cell line was lysed as efficiently as its normal counterpart, whereas infected HLA class I-deficient cells (Daudi cells) were not. The clone showed crossreaction between Yersinia enterocolitica , Escherichia coli , Pseudomonas aeruginosa , and Streptococcus pyogenes , but did not…

Identical T-cell expansions in the colon mucosa and the synovium of a patient with enterogenic spondyloarthropathy.

Abstract Intestinal T lymphocytes activated by antigen are suspected to play a key role in enterogenic spondyloarthropathies (SpA). Therefore, we aimed to identify and functionally characterize T-cell clones that are coexpanded in the intestinal mucosa and the synovium. Colon, peripheral blood, and synovium of a patient with enterogenic SpA were screened for clonal T-cell expansions by TCRB-CDR3 length analysis and sequencing. T-cell clones expanded in vivo were isolated from archived synovial cells by targeted T-cell cloning and characterized for phenotype, cytokine production, and antigen specificity. The synovial TCRBV18 + T-cell repertoire of the patient was dominated by 2 CD8 + T-cell …

Die retraktile Mesenteritis*: Diagnostische und therapeutische Aspekte

An 18-year-old boy, who had severe abdominal pain for 18 months associated with marked weight loss, was found to have a stenosed ileal sling on double-contrast radiology of the small intestine. At operation a plate-like tumour was extending from the pancreas to the aortic bifurcation. Histological examination of removed tissue revealed retractile mesenteritis (mesenteric panniculitis; liposclerotic mesenteritis). The symptoms regressed and the patient again gained weight under immunotherapy with 1 mg/kg of prednisone and 2 mg/kg of cyclophosphamide daily. Subsequently, under prednisone alone, there was a recurrence, which responded within five weeks to daily 60 mg prednisone and 125 mg cycl…

Proliferative response of synovial fluid and peripheral blood mononuclear cells to arthritogenic and non-arthritogenic microbial antigens and to the 65-kDa mycobacterial heat-shock protein

Cellular immune responses to microbial antigens have been implicated in the pathogenesis of some forms of arthritis including reactive arthritis, Reiter's syndrome, ankylosing spondylitis and rheumatoid arthritis. We investigated the proliferative T cell responses of paired peripheral blood (PB) and synovial fluid (SF) mononuclear cells (MC) to so-called arthritogenic bacteria (Yersinia enterocolitica and Salmonella typhimurium), to control antigens, such as Candida albicans, mumps virus and purified protein derivative, to the recombinant mycobacterial 65-kDa heat-shock protein (hsp 65) and the mitogen phytohemagglutinin (PHA) in 16 patients with different inflammatory rheumatic diseases. T…

Die Virulenz von A-Streptokokken im Verlauf verschiedener Wachstumsphasen

Es wird experimentell festgestellt, das der Virulenzgrad einer A-Streptokokkenkultur statistisch signifikant im Verlauf der verschiedenen Wachstumsphasen variiert. Zur Zeit der Latenzphase ist eine nur geringe Virulenz der Bakterienpopulation anzutreffen, sie steigt zu einem Maximum im Verlauf der log. Wachstumsphase an und sinkt in der stationaren Phase allmahlich wieder ab, bis zu niedrigen Werten im Bereich der Keimreduktionsphase. Diese Virulenzschwankungen der Population sind keine Funktion der Keimzahl (Injektion gleicher Keimmengen, praktisch konstantes Tot-Lebend-Keimverhaltnis), sondern sind als Ausdruck des Zustandes der Keime in den verschiedenen Wachstumsphasen aufzufassen.

T cells in reactive arthritis

T cells appear to play a major role in the development, maintenance and also resolution of reactive arthritis (ReA). Recent advances in understanding the processes involved in T cell activation now allow us to examine the peripheral blood and synovial fluid T cell responses to given "arthritogenic" microorganisms in terms of antigen specificity, epitope identification, cytokine secretion patterns, HLA restriction and the role of different T cell subsets in ReA. Peripheral blood bulk proliferation and limiting dilution studies provide evidence that the peripheral T cell response against arthritis-associated gram-negative bacteria is decreased in patients developing immunological sequelae suc…

Multiclonal Synovial T Cell Response toYersinia enterocoliticain Reactive Arthritis: TheYersinia61-kDa Heat-Shock Protein Is Not the Major Target Antigen

The T cell response to bacterial antigens plays a major role in the pathogenesis of reactive arthritis (ReA) following enteric infections with Yersinia enterocolitica. To study the antigen specificity of the T cells at the site of inflammation, the response of cloned T cells from the synovial fluid of 2 patients with ReA to partially purified antigens of Yersinia enterocolitica was determined. The clones showed different patterns of response to various fractions, indicating a multiclonal response to Yersinia antigens, and these specificities differed in the 2 patients. Some T cells were specific for Y. enterocolitica; some cross-reacted with other enterobacteria. Proteins of 14 and 19 kDa c…

Identification of the Yersinia enterocolitica urease beta subunit as a target antigen for human synovial T lymphocytes in reactive arthritis.

The local T-cell response to bacterial antigens is involved in the pathogenesis of reactive arthritis (ReA). Here, we have identified a 19-kDa antigen of Yersinia enterocolitica O:9 recognized by Yersinia-specific synovial fluid CD4+ T cells in two patients with Yersinia-induced ReA. N-terminal amino acid sequencing of this protein revealed that it was identical to the 19-kDa urease beta subunit of Y. enterocolitica O:9. This protein has previously been shown to be arthritogenic in preimmunized rats after intra-articular injection. Analysis of the T-cell response to this protein showed that it contains several T-cell epitopes, one of which cross-reacts with other enterobacteria not able to …

Salmonella-reactive Synovial Fluid T-cell Clones in a Patient with Post-infectious Salmonella Arthritis

From a patient with reactive arthritis following Salmonella typhimurium enteritis, synovial fluid T-lymphocytes were cloned and expanded in vitro. Seven out of 74 clones showed a marked proliferative response to antigens of heat-killed Salmonella typhimurium with autologous T-cell-depleted peripheral blood mononuclear cells as antigen-presenting cells. The Salmonella-reactive clones were of the CD4+ phenotype, antigen-induced proliferation could be inhibited by a monoclonal antibody to HLA class II. One clone recognized both Salmonella and Campylobacter jejuni antigens in the proliferation assay. The multiclonality of Salmonella-reactive synovial fluid T-cells indicates that the microorgani…

Synovial fluid-derivedYersinia-reactive T cells responding to human 65-kDa heat-shock protein and heat-stressed antigen-presenting cells

Humoral and cellular immune reactions to heat-shock proteins have been implicated in the pathogenesis of arthritis. Heat-shock proteins occur in bacteria as well as all eukaryotes and have been highly conserved during evolution. Cross-reactivity between bacterial and human heat-shock proteins induced at the site of inflammation may underlie the pathogenesis of some forms of arthritis. In order to test this hypothesis, we raised and cloned a Yersinia-specific T cell line from the synovial fluid lymphocytes of a patient with Yersinia-induced reactive arthritis. From this line we obtained a CD4+ T cell clone that proliferated in response to Yersinia antigens and both to the mycobacterial and t…

Stimulation of synovial fluid mononuclear cells with the human 65-kD heat shock protein or with live enterobacteria leads to preferential expansion of TCR-γδ+ lymphocytes

SUMMARY T lymphocyte responses to heterologous or self 65-kD heat shock protein (hsp) have been implicated in the pathogenesis of various forms of arthritis. To delineate the relationship of 65-kD hsp to different synovial fluid (SF) T cell subsets, we stimulated synovial fluid (SFMC) and peripheral blood mononuclear cells (PBMC) from patients with different inflammatory rheumatic diseases and from healthy controls with human or mycobacterial 65-kD hsp, tetanus toxoid (TT), heat-killed or live Yersinia enterocotitica. Phenotyping of the resulting T cell lines revealed an increase of up to 97% TCR-γδ+ lymphocytes in the 65-kD hsp-stimulatcd SF-derived lines. This expansion of TCR-γδ+ cells w…

Candida arthritis: cellular immune responses of synovial fluid and peripheral blood lymphocytes to Candida albicans.

A case of septic Candida albicans arthritis of the knee in a patient with systemic candidiasis is presented. Systemic and intra-articular cellular immune responses to C albicans and various bacterial antigens were monitored for 15 weeks. It is shown that the candida induced blastogenesis of synovial fluid lymphocytes was much more stimulated than that of peripheral blood lymphocytes, and that the proportion of activated cells expressing HLA class II antigens was markedly increased in the synovial fluid. Strong cellular immune responses to Candida albicans could still be shown many weeks after the synovial fluid aspirates had become sterile. For the first time synovial fluid derived, CD4 pos…

Predominance of Th1-type T cells in synovial fluid of patients with Yersinia-induced reactive arthritis

The pathogenetic mechanisms underlying the development of reactive arthritis and the functional capacities of synovial T cells specific for Yersinia enterocolitica are still unclear. In this study we have determined the cytokine secretion patterns of 24 CD4+ synovial fluid (SF)-derived T cell clones from 2 patients with Yersinia-induced reactive arthritis, 16 clones specific for different Yersinia antigens and 8 clones as controls. The clones specific for Yersinia antigens predominantly belong to the T helper cell 1 (Th1) subset with production of interferon (IFN)-gamma and interleukin (IL)-2, but no IL-4, whereas SF T cells not reactive with Yersinia antigens produce IL-2, IL-4 and IFN-gam…

Correlation of anti-cytoskeleton antibody activities in synovial fluid with interleukin-6 in patients with osteoarthritis and inflammatory joint disease

Synovial fluids and sera from patients with rheumatoid arthritis, psoriatic arthritis, yersinia arthritis, Behçet's syndrome, Crohn's disease, and osteoarthritis were tested for antinuclear antibodies and antibodies to five cytoskeletal components in sensitive enzyme-linked immunosorbent assay (ELISA) systems and for IL-6 concentrations in a proliferation assay (IL-6 dependent hybridoma cell line B13.29, subclone B9). Statistically significant correlations between antibody activities and IL-6 levels were found for vimentin antibodies (r = 0.56; p less than 0.05) and actin antibodies (r = 0.44; p less than 0.05). In patients with chronic and active disease like rheumatoid arthritis and psori…

Induction of an Anti-Vaccine Response by T Cell Vaccination in Non-human Primates and Humans

Abstract Experimental and spontaneous autoimmune disease in animals can effectively be prevented and treated by application of pathogenic autoreactive T cells in an attenuated form. This approach has become known as T cell vaccination, T cell vaccination exploits specifically the ability of the immune system to regulate its autoreactive T cells by mechanisms of network control. The success of T cell vaccination in a variety of rodent animal models has raised hopes for its use as an effective and specific therapy in human autoimmune disease. The aim of this study was to induce an anti-T cell response by T cell vaccination in humans and primates as a pre-clinical study into the feasibility an…

Bacteria-specific cytotoxic CD8+ T cells: a missing link in the pathogenesis of the HLA-B27-associated spondylarthropathies.

The term seronegative spondylarthropathies is used for an entity of rheumatic syndromes of peripheral joints and the spine (ankylosing spondylitis, reactive arthritis, Reiter's syndrome, arthritis in psoriasis and in inflammatory bowel disease) which are strongly associated with the MHC class I molecule HLA-B27. However, the mechanisms whereby HLA-B27 confers disease susceptibility have so far remained unknown. There is strong evidence that gut inflammation and infection with gram-negative bacteria play a role in the induction of B27-associated disease. HLA-B27, like other MHC class I molecules, physiologically binds antigenic peptides in its binding groove and presents them to CD8+ T lymph…