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

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 enterocolitica. Phenotyping of the resulting T cell lines revealed an increase of up to 97% TCR-gamma delta+ lymphocytes in the 65-kD hsp-stimulated SF-derived lines. This expansion of TCR-gamma delta+ cells was less pronounced with cultures of PBMC. A preferential expansion of TCR-gamma delta+ cells was also shown after SFMC stimulation with live, but not with heat-killed Yersinia or with TT. We conclude that a common mechanism is involved in the selective expansion of TCR-gamma delta+ lymphocytes upon SFMC infection with live Yersinia or upon contact with 65-kD hsp. Out of a panel of TCR-gamma delta+ T lymphocyte clones (TLC) derived from a human 65-kD hsp-stimulated line, only a minority of TLC proliferated weakly upon restimulation with this antigen in the presence of autologous monocytes, whereas TCR-alpha beta+ TLC responded vigorously to the human 65-kD hsp and in some cases also cross-recognized the mycobacterial hsp homologue and/or heat-killed Yersinia. This implies that additional factors or cells may be present in the milieu of SFMC cultures that propagate the expansion of TCR-gamma delta+ cells in response to 65-kD hsp or live bacteria.     

T helper type-1 (Th1)/Th2 profiles of peripheral blood mononuclear cells (PBMC); responses to antigens of Chlamydia trachomatis in subjects with severe trachomatous scarring

The 65-kD hsp from Mycobacterium tuberculosis has been reported to induce an autopathogenic subset of T cells in at least two animal models of autoimmune disease. Reports of increased expression of human hsp60 in the inflamed synovial tissue of rheumatoid arthritis (RA) patients, increased proliferation of RA synovial fluid T cells to mycobacterial hsp65, and increased levels of anti-mycobacterial hsp65 antibody in synovial fluid, have suggested that the highly homologous human (hu) hsp60 may be recognized as an autoantigen in RA patients. In the present study, we have examined by ELISA the serum IgG antibody levels to mycobacterial hsp65 and hu hsp60, as well as to the Escherichia coli hsp60, groEL, in patients with RA, systemic lupus erythematosus (SLE), Reiter's syndrome, active tuberculosis, and normal controls. In all these groups, the levels of anti-groEL and anti-hu hsp60 were significantly higher than the anti-mycobacterial hsp65. Anti-hu hsp60 was positively correlated with anti-groEL, but not with anti-mycobacterial hsp65. Anti-hu hsp60 was competitively inhibited by either soluble groEL or hu hsp60, but little or none by mycobacterial hsp65. Reiter's sera were found to have somewhat higher levels of anti-groEL and anti-hu hsp60 than did normal controls. We conclude that IgG anti-hu hsp60 autoantibodies arise primarily as a consequence of the humoral immune response to E. coli groEL through the recognition of cross-reactive epitopes.     

Limiting-dilution analysis of T cell reactivity to mycobacterial antigens in peripheral blood and synovium from rheumatoid arthritis patients.

Limiting-dilution analysis (LDA) was used to quantify the frequency of Mycobacterium bovis BCG- and 65-kD-reactive T cells in paired samples of peripheral blood and synovial tissue from patients with rheumatoid arthritis. The frequency of BCG-reactive T cells detected in the peripheral blood of patients ranged from 1/585 to 1/7639 versus a control frequency range of 1/480 to 1/6773. The frequency of such cells in the synovium was found to be much lower than it was in peripheral blood; in fact, in 80% of patients synovial BCG-reactive T cells were not detected. The frequency of 65-kD-reactive cells in the peripheral blood of each individual was lower than the frequency of BCG-reactive cells (range 1/3738 to 1/55,324), as would be expected. However, no synovial 65-kD-reactive cells were detected from any of the patients studied. The LDA assay for the 65-kD antigen was consistent with the single hit model, that for BCG was not. The relatively high proportion of mycobacterial-reactive precursors seen in the peripheral blood of non-vaccinated individuals may reflect a population of cells induced either by natural environmental exposure to mycobacteria or, given the highly conserved nature of heat shock proteins across phylogeny, by some other infection. The results also suggest that the frequent finding of reactivity to proteins such as the 65-kD heat shock protein contained within BCG may not be a generalized phenomenon in rheumatoid synovium.     

Peptide recognition, T cell receptor usage and HLA restriction elements of human heat-shock protein (hsp) 60 and mycobacterial 65-kDa hsp-reactive T cell clones from rheumatoid synovial fluid.

A commonly held postulate regarding the etiology of rheumatoid arthritis (RA) is that of antigenic mimicry. Recent interest has focused on the mycobacterial 65-kDa heat-shock protein (hsp) as a putative causal agent. The 65-kDa hsp has over 40% sequence homology with the human hsp 60, and elevated synovial T cell responses to both antigens have been demonstrated in RA and juvenile rheumatoid arthritis patients. Such T cells should, therefore, be specific for shared epitopes on the two antigens. To investigate this, we screened synovial fluid mononuclear cells from two early RA patients with peptides of the 65-kDa hsp which have the greatest homology with the human hsp 60. We also raised a panel of T cell clones from one of the patients with the 65-kDa hsp. The synovial T cell population from both patients and one of the T cell clones recognized a peptide representing the amino-acid sequence 241-255. This clone also responded to the peptide of the equivalent human sequence, and was restricted by HLA-DQ. A second T cell clone recognized an adjacent epitope (amino acid sequence 251-265) which is also highly homologous with the human sequence, but this clone was restricted by HLA-DR. The clones utilized different V beta gene segments but the same D beta and J beta gene elements, and both exhibited specific cytotoxicity against autologous antigen-pulsed macrophages. Our findings, therefore, do not disagree with the postulate that autoimmune disease could possibly be triggered by bacterial epitopes with homology to self protein. However, it is also noted that there are alternative interpretations of this data.     

Epitope specificity and MHC restriction of rheumatoid arthritis synovial T cell clones which recognize a mycobacterial 65 kDa heat shock protein.

CD4+ T cell clones specific for the mycobacterial hsp 65 were obtained from synovial fluid of a DR4 homozygous rheumatoid arthritis (RA) patient. A stimulatory epitope was defined using both deletion mutants of the mycobacterial hsp 65 and synthetic peptides and proved to be in a highly conserved region of the molecule. Despite this, however, there was no recognition by these clones of either the recombinant human homologue of mycobacterial hsp 65, P60, nor of a synthetic peptide containing an amino acid sequence from P60 corresponding to the epitope defined in the mycobacterial hsp 65. When the pattern of HLA restriction shown by the hsp-65-specific T cell clones was investigated, all clones tested proved to be restricted by HLA-DP rather than the more usual HLA-DR. Inhibition experiments suggested that this restriction also applied to the polyclonal synovial T cell response to hsp 65, but not to other antigens. Exclusive restriction of T cell recognition of an antigen by HLA-DP has not been reported previously, and strongly suggests that in this case the T cell repertoire for recognizing hsp 65 in the context of DR4 is deficient. Such an association between DR4 and the inability to respond to an immunodominant bacterial antigen may have implications for the pathogenesis of RA.     

Synovial Cells Responding to a 65-kDa Mycobacterial Heat Shock Protein have a High Proportion of a TcRγδ Subtype Uncommon in Peripheral Blood

We have analysed the ability of T cells from synovial fluid mononuclear cells (SFMC) and from peripheral blood mononuclear cells (PBMC) of inflammatory arthritic diseases to proliferate in response to mycobacterial antigens (65-kDa heat shock protein [hsp] of BCG, whole BCG) and to rat collagen type II. The SFMC demonstrated a significantly greater ability to respond to 65-kDa hsp of BCG, and to whole BCG, compared with PBMC from the same patients. With collagen type II, only a small proportion of the patients showed a proliferative response, although with this antigen also SFMC responded better than PBMC. There was no difference between SFMC and PBMC in the response to control antigen (tetanus toxoid), phytohaemagglutinin (PHA), or interleukin 2 (IL-2). A high proportion of cells in SFMC-derived short-term T-cell lines were of TcR gamma delta type, often exceeding the number of TcR gamma beta type. There was a significantly higher proportion of TcR gamma delta cells in the SFMC lines compared with the PBMC lines, and a large part of the TcR gamma delta cells in the SFMC cultures was CD8+. The SFMC lines had a high proportion of delta-TCS-1+ cells (V delta 1) among their TcR gamma delta cells, always exceeding the percentages of Ti gamma A+(V gamma 9) and BB3+ (V delta 2). In the PBMC lines, the distribution of TcR gamma delta subtypes was markedly different, with a Ti gamma A+/BB3+ population in the majority. These data argue for a different subpopulation distribution of TcR gamma delta cells in synovial fluid compared with peripheral blood of patients with inflammatory arthritic diseases.     

Expression of TLiSA1 on T cells from patients with rheumatoid arthritis and systemic lupus erythematosus

The expression of a new activation antigen, T cell lineage specific activation antigen (TLiSA1) on peripheral blood T cells from 16 rheumatoid arthritis (RA) and 8 systemic lupus erythematosus (SLE) patients and synovial fluid T cells from RA patients was determined in the context of T cell activation. The percentages of TLiSA1 positive T cells from inactive (4.6 +/- 5.2, mean +/- SE) or active RA (19.3 +/- 8.6) or inactive (1.7 +/- 2.1) or active SLE (8.7 +/- 2.7) were significantly increased compared with that of normal controls (0.7 +/- 0.4) (P less than 0.01). All patients with vasculitis showed relatively high positive percentages. The mean fluorocytometric intensity of TLiSA1 positive T cells from RA and SLE patients was significantly higher than that from normals. Percentages of TLiSA1 positive T cells from synovial fluids (21.8 +/- 4.9%) were significantly increased compared with those from peripheral blood of the same patients, indicating the local activation of T cells in patients with RA. An increase in the expression of TLiSA1 with no increase in the expression of the very late activating antigen 1 (VLA-1) was found in peripheral blood from RA, suggesting a difference in the stage of T cell activation in RA. In RA, there was a clinical correlation with levels of TLiSA1 expression on peripheral T cells. After stimulation with PHA, TLiSA1 positive percentages were increased on Day 2 and continued to increase through 5 days of culture. The maximum expression was obtained on Day 5. An increased number of TLiSA1 positive T cells belonged to OKT8. These results suggest that there is the systemic and the local activation of T cells in RA, following antigen stimulation, or a generalized nonspecific activation of immune system that could provide a means to monitor the abnormal immunologic activity in RA.     

Detection of T-Lymphocyte Subpopulations in the Peripheral Blood and the Synovium of Patients with Rheumatoid Arthritis and Juvenile Rheumatoid Arthritis Using Monoclonal Antibodies

Monoclonal antibodies with specificities for various human T-cell antigens were used in direct immunofluorescence to quantify the proportions of T lymphocytes with suppressor/cytotoxic-cell markers and with helper/inducer-cell markers and of T lymphocytes with HLA-DR antigens. Normal percentages of lymphocytes with suppressor/cytotoxic-cell markers were detected in the peripheral blood synovial fluid and synovial tissue lymphocytes from patients with juvenile rheumatoid arthritis (JRA) and rheumatoid arthritis (RA), respectively. Normal percentages of T lymphocytes with helper/inducer-cell markers were seen in the peripheral blood of RA and JRA patients and in the synovial tissues of RA patients. Slightly decreased percentages of cells with the helper/inducer-cell marker were detected in the synovial fluids of JRA patients. The proportions of HLA-DR-positive T lymphocytes were highly increased in the synovial fluid and synovial tissue, whereas the numbers of these cells in the peripheral blood were normal. No significant differences in T gamma cells were detected between peripheral blood, synovial fluid and synovial tissue of JRA patients or between peripheral blood and synovial tissue of RA patients.     

T gamma delta cells in juvenile rheumatoid arthritis and rheumatoid arthritis. In the juvenile rheumatoid arthritis synovium the T gamma delta cells express activation antigens and are predominantly V delta 1+, and a significant proportion of these patients have elevated percentages of T gamma delta cells

Using the anti-TcR gamma/delta-1 monoclonal antibody and flow cytometry, we examined the number of T gamma delta cells in paired samples of peripheral blood and synovial fluid or tissue from 24 children with juvenile rheumatoid arthritis (JRA), five adult patients with JRA, and 14 patients with rheumatoid arthritis (RA). No significant difference was found in the synovial compartment T gamma delta values compared with the blood in JRA, adult JRA, or RA patients. Nor was any significant difference found in the peripheral blood or synovial compartment T gamma delta values in any of the three patient groups compared with the peripheral blood of normal controls. However, seven of the children with JRA had very high T gamma delta values in the synovial compartment while none of the normal children had high T gamma delta values in the blood (P = 0.02, Fisher's exact test). This may indicate a possible separate JRA patient group with high T gamma delta levels in the synovial compartment. In six JRA patients further analysed for T gamma delta subpopulations, a significant predominance of V delta 1+ cells was found in the synovial compartment compared with the corresponding peripheral blood samples (P less than 0.05, Wilcoxon's signed test) and with peripheral blood of child controls (P less than 0.05, Mann-Whitney U test). In these six patients, the T gamma delta-cell expression of the very early activation antigen CD69 were significantly higher (P less than 0.05, Wilcoxon's signed test) in the synovial compartment compared with the peripheral blood. Synovial T gamma delta cells expressing HLA-DR and interleukin 2 receptors could also be detected, in contrast to the peripheral blood in which no T gamma delta cells expressing these antigens could be found. These data suggest that the synovial T gamma delta cells had been activated in vivo.     

Diversity in antigen recognition by Mycobacterium tuberculosis-reactive T cell clones from the synovial fluid of rheumatoid arthritis patients

In a previous study we have shown that synovial fluid mononuclear cells from many rheumatoid arthritis (RA) patients exhibit an enhanced response to M. tuberculosis antigens as compared to peripheral blood mononuclear cells. The 65-kDa heat-shock protein of M. tuberculosis was shown not to play an important role in this response, therefore other mycobacterial proteins must be involved. In this study we have investigated the possibility that synovial fluid T cells from RA patients predominantly recognize a limited number of M. tuberculosis antigens, as a result of a lesion-specific activation of only those M. tuberculosis-reactive T cells that have cross-reacted with joint-related autoantigens. From the synovial fluid of four RA patients M. tuberculosis-reactive T cell clones were isolated and analyzed for their phenotype, HLA-DR restriction and proliferation to immunoblot fractions containing sodium dodecyl sulfate-polyacrylamide gel-separated M. tuberculosis proteins of known molecular weight range. The overall M. tuberculosis immunoblot recognition pattern of the clones was strikingly heterogeneous. Within a panel of 15 clones 12 different antigenic specificities could be distinguished. In other words, we did not observe a dominant recognition of a few M. tuberculosis antigens by synovial fluid T cells. This argues against the hypothesis that the elevated synovial T cell reactivity against M. tuberculosis is a reflection of an in vivo expansion of a limited number of different types of M. tuberculosis-reactive T cells as a result of a cross-reaction with putative joint autoantigens.     

Heat shock proteins and autoimmunity in humans

Summary T cells and antibodies against self and non-self hsp are present in both patients and healthy controls. T cells responding to hsp65 can be involved in autoimmune diseases, this was demonstrated for two site-specific animal autoimmune diseases: AA in Lewis rats and diabetes (IDDM) in NOD mice. In human ReA there is evidence for a direct stimulation of joint T cells by antigens of the organisms causing the infection which precedes the joint inflammation. The individual antigens of the triggering bacteria still have to be defined, but hsp65 may be of importance since this is one of the molecules recognized by synovial T cells in ReA patients.In RA there are no clear data implicating an infection in the initiation of joint inflammation, but mycobacteria have been suggested to be involved. We have discussed experimental findings which are in favor of, or in contradiction with, a role of mycobacterial antigens — particularly hsp65 — in the etiology of RA. T cells recognizing hsp65 and other mycobacterial antigens are present in the joint, but there is no indication for a specific involvement of one or a limited set of (myco)bacterial antigens in the pathogenesis of RA.     

类风湿性关节炎中树突状细胞亚群分析

目的 分析类风湿性关节炎患者外周血和关节液中的DC(dendritic cell,DC)亚群以及DC亚群与炎症产生的关系.方法 收集来自西南医院体检中心26例健康人外周血作为对照组,来自西南医院风湿免疫科28例RA患者的外周血及滑膜液作为实验组,其中RA患者的外周血和滑膜液来自同一 RA患者.采用人外周血淋巴细胞分离液...     

Interleukin-21 induces T-cell activation and proinflammatory cytokine secretion in rheumatoid arthritis

Interleukin (IL)-21 is a CD4+ T-cell-derived cytokine, which is involved in innate and adaptive immune response. In this study, we analysed IL-21 receptor (IL-21R) expression in peripheral blood and synovial fluid mononuclear cells, and investigated the role of IL-21 in the induction of proinflammatory cytokine production by peripheral blood T cells (PB-T) and synovial fluid T cells (SF-T) from patients with rheumatoid arthritis (RA). Immunohistochemical staining demonstrated that IL-21R-positive cells were significantly increased in inflamed synovial tissues of RA patients compared with osteoarthritis (OA) and healthy controls. Flow cytometric analysis confirmed that IL-21R was mainly expressed in freshly isolated CD4, CD8, B and NK cells from peripheral blood and synovial fluid, but decreased gradually in T cells 24 h after anti-CD3 stimulation. PB- and SF-T cells from RA patients were more responsive to IL-21 when compared with controls. Importantly, isolated PB- or SF-T cells from RA patients, when stimulated with IL-21 and anti-CD3 MoAb, secreted markedly higher levels of TNF-alpha and IFN-gamma than controls. These data indicate that IL-21R is overexpressed in the inflamed synovial membrane and in peripheral blood or synovial fluid leukocytes of RA patients, and that IL-21 enhances local T-cell activation, proliferation and proinflammatory cytokine secretion. Thus, blockade of IL-21R signalling pathway may have a therapeutic potential in acute RA patients.     

Autologous Mixed Lymphocyte Reactions in Patients with Rheumatoid Arthritis and Juvenile Rheumatoid Arthritis: Both Non-T Cells and in-Vivo-Activated T Cells Can Act as Stimulator Cells

The lymphocyte responses in autologous mixed lymphocyte reactions (AMLR) between irradiated non-T and T lymphocytes from the peripheral blood (PB) of rheumatoid arthritis (RA) and juvenile RA (JRA) patients were decreased compared with the AMLR responses of normal PB lymphocytes. Normal AMLR responses were seen in the synovial tissue and the synovial fluid lymphocytes from RA and JRA patients. The lymphocyte responses were also decreased in AMLR between irradiated non-T cells from peripheral blood and T cells from synovial tissue (ST) in RA patients and between irradiated non-T from PB and synovial fluid (SF) T cells in JRA patients. However, when irradiated non-T cells from ST of RA patients or from SF of JRA patients were mixed with autologous PB T lymphocytes, increased lymphocyte responses were observed. SF T lymphocyters and ST T cells were also shown to stimulate autologous PB T lymphocytes.     

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 entero-colitica 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. The [³H]thymidine uptake of unstimulated cells (medium control) as well as the proliferative response to the different antigens tested was markedly increased in SFMC irrespective of the underlying rheumatic disease. In contrast, mitogenic stimulation was decreased in SFMC. The proliferative response to the hsp 65 correlated significantly with the responses to Yersinia, Salmonella and Candida. These results may reflect an enhanced function of SF antigen-presenting cells, different functional properties and subset distributions of PB and SF T cells with a preferetial accumulation of helper-inducer/memory T cells or a maintenance of an ongoing immune response by T cells cross-recognizing self epitopes such as epitopes located on the hsp 65. Thus, care should be taken in the interpretation of SF T cell responses to microbial antigens as diagnostic tools in arthritis.     

CD4+CD25high调节性T细胞在类风湿性关节炎病程中的消长及其意义

目的研究类风湿性关节炎(RA)患者病情发展不同阶段外周血及滑液中CD4 CD25high调节性T细胞数量的差别,及其与类风湿性关节炎活动程度的相关性,探讨CD4 CD25highT细胞在RA发生发展中所发挥的免疫抑制和调节作用。方法分别选取未经过缓解病情抗风湿药(DMARDs)治疗的活动性RA患者11例,经DMARDs治疗病情缓解的RA患者12例,和DMARDs治疗后效果不佳的RA患者9例,以及正常对照8例,检测他们的外周血淋巴细胞,以流式细胞术检测CD4 CD25high调节性T细胞的百分率,并研究CD4 CD25highT细胞百分率与抗环瓜氨酸(CCP)抗体,C反应蛋白(CRP),血沉(ESR)及类风湿因子(RF)的相关性。对其中部分患者的血液和关节滑液同时进行分析。结果RA未经治疗组和治疗效果不佳组CD4 CD25highT细胞的百分率(分别是5.24%和6.43%)明显低于正常对照组和治疗后病情缓解组(分别是17.17%和11.79%,P<0.01)。RA患者CD4 CD25highT细胞的百分率与抗CCP抗体(58.0Ru/mL),ESR(38.8mm/h)及CRP(2.73μg/L)呈明显负相关(P<0.05),与类风湿因子(RF=14.4Iu/mL)无明显的相关性(P=0.054)。正常对照组的CD4 CD25highT细胞百分率与抗CCP抗体(均<5.0Ru/mL),ESR(4.67mm/h),CRP(0.15μg/L)及RF(1.37)无明显相关性(P>0.1)。RA患者关节滑液中CD4 CD25highT百分率明显低于强直性脊柱炎(ankilosing spondylitis,AS)关节积液患者(P<0.05)。结论试验结果表明未经缓解病情治疗和治疗后效果不佳者的外周血中,CD4 CD25high调节性T细胞相对减少,且与病情活动程度负相关,这可能是RA发生和发展的一个重要因素。     

In Vitro Mitogen Stimulation of Synovial Fluid Lymphocytes from Rheumatoid Arthritis and Juvenile Rheumatoid Arthritis Patients: Dissociation between the Response to Antigens and Polyclonal Mitogens

The in vitro responses to mitogens of synovial fluid lymphocytes obtained from eight patients with rheumatoid arthritis (RA) and eight patients with juvenile rheumatoid arthritis (JRA) were studied. The results were compared to the transformation of the patient's peripheral blood lymphocytes stimulated with the same mitogens. Both RA and JRA synovial fluid lymphocytes showed a low transformation to the polyclonal mitogens PHA and PWM with a low ratio PHA-response/PWM-response. The stimulatory effect of purified protein derivative of tuberculin (PPD) was high, whereas a Candida albicans antigen preparation gave a more variable stimulation of the synovial fluid lymphocytes. In some patients the complete mitogen transformation profile of lymphocytes obtained from synovial fluid, synovial tissue and peripheral blood was studied. The results of the synovial fluid and tissue lymphocytes were similar.     

Gamma/delta T cells and their subpopulations in blood and synovial fluid from rheumatoid arthritis and spondyloarthritis.

T cell receptor (TCR) gamma/delta bearing lymphocytes in peripheral blood and synovial fluid from rheumatoid arthritis (RA) and seronegative spondyloarthritides (SSA) were evaluated by means of double label immunofluorescence and cytofluorographic analysis. Three monoclonal antibodies (MAb) were used. TCR delta-1 against a common delta chain epitope, BB3 directed against the T cell subset whose TCR is encoded by the V delta 2 gene, and A13 directed against the V delta 1 subset. Peripheral blood T gamma delta cells were significantly reduced compared to normal control blood in RA patients who had joint effusion but not in other RA patients. The decrease of T gamma delta in the RA PB was mainly confined to the A13+ subset. In RA synovial fluid (RA SF) T gamma delta cells were significantly increased compared to paired but not normal peripheral blood, the most significant being the increase of A13+ cells. In contrast, in patients with SSA, no change in T gamma delta cells was observed on PB or SF. These data suggest that in RA, but not SSA, T gamma delta cells migrate from PB to inflamed synovium and thus may be involved in the pathogenesis of RA.     

Expression of TIM‐3 on CD4+ and CD8+ T cells in the peripheral blood and synovial fluid of rheumatoid arthritis

Rheumatoid arthritis (RA) is characterized by a chronic inflammatory process that targets the synovial lining of diarthrodial joints. TIM‐3 plays a key role in the negative regulation of the immune response. In this study, we investigated the expression of TIM‐3 on CD4+ and CD8+ T cells from systemic (peripheral blood) and local (synovial fluid) perspectives of RA. Level of TIM‐3+ cells from peripheral blood and synovial fluid of patients as well as peripheral blood of healthy controls was measured by flow cytometry. Results showed that TIM‐3 expression was significantly increased in both CD4+ and CD8+ T cells in the peripheral blood of RA (p < 0.001 and p < 0.001, respectively). Furthermore, patients revealed even higher expression of TIM‐3 in CD4+ and CD8+ T cells in synovial fluid than in peripheral blood. When comparing TIM‐3 level with the severity of RA, we identified that the percentage of TIM‐3 on both peripheral CD4+ and peripheral CD8+ T cells was negatively correlated with disease activity score 28 (DAS28) of the patients. Similarly, TIM‐3 on synovial fluid CD4+ and CD8+ T cells also revealed inverse correlation with DAS28 of the cases. Our data demonstrate a negative correlation between TIM‐3 and the disease progression of RA.