树突状细胞在类风湿关节炎中的研究进展

类风湿关节炎(RA)是以关节滑膜炎为主要特征的全身性、炎性反应自身免疫病。目前认为RA的发生是由抗原提呈细胞(APC)对自身抗原的异常提呈所引起的。树突状细胞(DC)是已知功能最强的APC,它能处理并提呈抗原,引发免疫应答;同时它还具有诱导免疫耐受的功能,这一特点使其可能成为临床治疗RA的新途径。     

Altered metabolic pathways regulate synovial inflammation in rheumatoid arthritis

Rheumatoid arthritis is characterized by synovial proliferation, neovascularization and leucocyte extravasation leading to joint destruction and functional disability. The blood vessels in the inflamed synovium are highly dysregulated, resulting in poor delivery of oxygen; this, along with the increased metabolic demand of infiltrating immune cells and inflamed resident cells, results in the lack of key nutrients at the site of inflammation. In these adverse conditions synovial cells must adapt to generate sufficient energy to support their proliferation and activation status, and thus switch their cell metabolism from a resting regulatory state to a highly metabolically active state. This alters redox-sensitive signalling pathways and also results in the accumulation of metabolic intermediates which, in turn, can act as signalling molecules that further exacerbate the inflammatory response. The RA synovium is a multi-cellular tissue, and while many cell types interact to promote the inflammatory response, their metabolic requirements differ. Thus, understanding the complex interplay between hypoxia-induced signalling pathways, metabolic pathways and the inflammatory response will provide better insight into the underlying mechanisms of disease pathogenesis.     

Induction of Fas-dependent apoptosis in synovial infiltrating cells in rheumatoid arthritis

Apoptosis is a feature of the synovium of rheumatoid arthritis(RA). We have recently shown that RA synoviocytes were susceptibleto anti-Fas mAb and undergo apoptosis in vitro. To investigatewhether infiltrating mononuclear cells also undergo Fas-dependentapoptosis, double-labeling techniques combined with immunohistochemicalexamination with anti-CD3 mAb and the TdT-mediated dUTP-biotinnick end labeling (TUNEL) method to detect apoptotic cells,or in situ RT assay to detect Fas mRNA, were performed usingfrozen tissue sections. We also examined the in vitro inductionof Fas-dependent apoptosis in freshly isolated synovium infiltratingmononuclear cells (SIM), synovial stromal cells (SSC) and peripheralblood lymphocytes (PBL) using tissues from nine patients withRA and three with osteoarthritis (OA). The results showed expressionof Fas antigen and apoptotic cells in a number of CD3-bearingcells in RA synovial tissues. In vitro treatment with anti-FasmAb produced a significant apoptosis of RA SIM and SSC, whilenone of PBL, and neither SIM nor SSC from OA exhibited apoptosis.Moreover, 50% of CD4⁺, CD3⁺ and CD45RO⁺ cells, and >90% ofFas-expressing cells of RA SIM underwent apoptosis in responseto anti-Fas mAb, as detected by flow cytometry. Our resultssuggest that RA synovial infiltrating lymphocytes acquire highsusceptibility to anti-Fas mAb and undergo apoptosis. Such aphenomenon of infiltrating T cells in RA synovium may play animportant pathophysiological role and suggest a possible therapeuticeffect for anti-Fas mAb in RA.     

Baricitinib for the treatment of rheumatoid arthritis and systemic lupus erythematosus: a 2019 update

ABSTRACT

Introduction: JAK, which constitutively binds to some cytokine receptors, plays an important role in cytokine signaling. While JAK is comprised of JAK1, JAK2, JAK3, and Tyk2, more than 40 types of cytokines transmit signals through JAK. Baricitinib is reported to be highly effective in the treatment of rheumatoid arthritis (RA) and is the second drug launched as a JAK inhibitor for RA.

Area covered: We provide an overview of the mechanisms of action of baricitinib and its clinical implications in RA and other autoimmune diseases based on recent reports. This review outlines the mechanisms of action of baricitinib on human immune cells, the results of Phase III trials for RA, and the results of Phase II trials on SLE.

Expert opinion: Baricitinib has potential to fine-tune various immune networks through a variety of mechanisms. Precision medicine is required in order to achieve maximum effects of targeted synthetic DMARDs including baricitinib and biological DMARDs in the future.     

The distribution and functional properties of dendritic cells in patients with seronegative arthritis.

Dendritic cells (DC), potent antigen-presenting cells, are known to be increased in numbers in inflammatory lesions in rheumatoid arthritis and juvenile chronic arthritis. In this study, patients with seronegative arthritis were studied; the distribution and functional properties of DC enriched low density cells (LDC) from peripheral blood (PB) and synovial fluid (SF) were compared. The composition of LDC from both sources was similar, comprising approximately 30% DC, 60% monocytes with few T lymphocytes. SF was significantly enriched for LDC compared with paired peripheral blood (P less than 0.0001) or peripheral blood from healthy controls (P less than 0.001). In contrast, patient PB contained fewer LDC (P less than 0.05) overall than healthy controls. LDC from both sources were potent simulators of allogeneic PB T cells in a mixed leucocyte reaction (MLR), but in four out of 10 patients SF LDC were significantly more stimulatory. In autologous MLRs (AMLRs) SF T cells were not stimulated by either LDC population. This anergy of T cells was confined to the joint as patient PB T cells showed an AMLR response to PB LDC which was similar to that seen in cells from healthy controls. PB T cells also responded to SF LDC; in a minority of patients SF LDC caused significantly greater stimulation in AMLR than PB LDC and the possibility is discussed that this may represent presentation of antigen acquired in vivo.     

DC固有胆碱能系统与JIA炎症免疫反应的关系

目的 探讨树突状细胞(DC)固有胆碱能系统与幼年特发性关节炎(JIA)炎症免疫反应的关系.方法 分离正常小鼠骨髓细胞,体外采用细胞因子诱导、分化,并刺激其成熟.通过细胞形态变化和表面分子对细胞鉴定;流式细胞术检测正常血清、JLA活动期血清和JIA活动期血清+美加明(MEC)3组血清对DC nAChRα7表达的影响;ELISA方法检测三组血清作用DC 18 h前后,培养上清中IL-12含量;MTT法和流式细胞术分别检测正常血清刺激的DC条件培养液组、JIA活动期血清刺激的DC条件培养液组、MEC干预的JIA活动期血清刺激的DC条件培养液组对小鼠脾淋巴细胞增殖活化的影响.结果 3组血清作用于成熟DC 18 h后DC nAChRα7表达为,JIA活动期血清组比正常血清组明显增强(P<0.05),而MEC作用后,nAChRα7表达有下调趋势;三组血清作用于成熟DC 18 h前后,培养上清中IL-12含量分别为,JIA活动期血清组比正常血清组IL-12含量均明显增高(P<0.01),而培养后,MEC干预组IL-12含量较JIA活动期血清组更高(P<0.05);3组血清刺激的DC条件培养液联合小剂量ConA对小鼠脾淋巴细胞增殖结果(SI值)和CD69表达是,MEC干预组增殖作用和CD69表达最强,JIA活动期血清刺激的DC条件培养液组次之.与正常血清刺激的DC条件培养液组比较增殖作用显著(P<0.01).结论 JIA活动期血清能刺激DC,使nAChRα7表达上调;MEC则下调DC nAChRα7表达,同时,伴有IL-12等炎性因子分泌及淋巴细胞增殖活化增强.故JIA的发生和活化可能与抑制DC胆碱能系统的抗炎作用有关,恢复胆碱能系统的正常调节可能是JIA治疗方向之一.     

Rheumatoid arthritis and pigmented villonodular synovitis: comparative analysis of cell polyploidy, cell cycle phases and expression of macrophage and fibroblast markers in proliferating synovial cells

AIMS: Rheumatoid arthritis (RA) and pigmented villonodular synovitis (PVNS) are aggressive diseases with progressive joint destruction. The present study aims to define cell cycle phases, polyploidy and the immunophenotype of proliferating synovial cells in both diseases. METHODS AND RESULTS: Synovial tissues from patients with proliferative-active RA, localized and diffuse PVNS were analysed by DNA flow cytometry, immunohistochemistry and double immunofluorescence with confocal laser scan microscopy. Expression of macrophage markers (CD68/CD163), fibroblast markers (h4Ph/CD55) and Ki67 antigen was examined. Synovial cells positive for either macrophage or fibroblast markers as well as double-labelled cells were found in both RA and PVNS. In RA, CD68/CD163+ synoviocytes were preferentially located in the vicinity of the synovial lining layer, while they were more randomly distributed in PVNS. Of cases with diffuse PVNS, 20% showed an aneuploid cell pattern. All samples of localized PVNS and RA were diploid. Proliferative activity was significantly higher in aneuploid PVNS. CONCLUSIONS: In spite of their histologically homogeneous appearance, proliferating synovial cells display a heterogeneous immunophenotype in both RA and PVNS, indicating functional properties of both macrophages and fibroblasts. Aneuploidy seems to be a special feature of diffuse PVNS.     

猪苓多糖刺激/诱导小鼠树突状细胞成熟

研究猪苓多糖对小鼠骨髓树突状细胞(DC)表型及功能成熟的影响。从小鼠骨髓中分离单个核细胞(MNC),用rmGM-CSF、IL-4培养5 d后,实验组加入猪苓多糖(50μg/ml),空白对照组加等量RPMI 1640,阳性对照组加LPS(1μg/ml),3组分别同时作用48 h。扫描电镜观察其体外培养过程中的形态特征,流式细胞仪(FACS)分析其表型特征,混合淋巴细胞反应(MLR)检测其功能。用猪苓多糖刺激的小鼠骨髓MNC具典型的DC形态;细胞表达I-A/I-E、CD11c和分泌IL-12能力比空白对照组增加,具有极强的激发MLR的能力,显示成熟DC的特征。猪苓多糖可以促进体外培养的小鼠骨髓DC的成熟,促进DC诱导的免疫应答启动。     

Rheumatoid factor production by mononuclear cells derived from different sites of patients with rheumatoid arthritis.

To investigate the origin of circulating rheumatoid factor (RF) and the relation between RF production at different sites in patients with rheumatoid arthritis (RA), mononuclear cells derived from bone marrow, synovium and peripheral blood of patients with RA were examined for the presence of plasma cells and for their capacity to produce RF and other immunoglobulins in vitro. Analysis of culture supernatants for the presence of immunoglobulins demonstrated that cells derived from bone marrow, synovium and peripheral blood were all found to be capable of producing every immunoglobulin and RF isotype investigated. No significant correlations were found between concentrations of immunoglobulin isotypes produced by cells derived from different sites of one individual. Significant correlations were found, however, between concentrations of RF isotypes produced by cells derived from the three sites. These results indicate that the production of RF in the different compartments is not an autonomously regulated process. Mononuclear cells derived from bone marrow were found to be able to produce RF in similar quantities to cells dissociated from synovial tissue. In combination with the fact that circulating immunoglobulins are produced mainly in the bone marrow, this observation suggests that bone marrow is also a major source of circulating RF.     

Peripheral blood and synovial fluid T cells differ in their response to alloantigens and recall antigens presented by dendritic cells.

Properties of T cells from inflammatory lesions were analysed by comparing the response of peripheral blood (PB) and synovial fluid (SF) T cells from 19 patients with a range of arthropathies to enriched allogeneic dendritic cells (DC) in a primary mixed leucocyte reaction (MLR). In 17 patients the proliferative response of SF T cells was significantly (P less than 0.05) less than that of PB lymphocytes. The reduced response of SF T cells was observed in all disease categories studied and could not be attributed to differences in cell number requirements or response kinetics. Addition of recombinant interleukin-2 enhanced the response of SF T cells in a dose-dependent manner. Cell mixing experiments suggested that active suppression was not the underlying mechanism of the poor MLR response of SF T cells. In contrast to the MLR response. SF T cells were able to mount vigorous proliferative responses to recall antigen presented by autologous antigen-presenting cells. The possibility is discussed that T cells compartmentalized at inflammatory lesions are a unique population with a diminished ability to interact with DC and respond to primary stimuli but an ability to respond to secondary antigenic challenge.     

Local synthesis of both macrophage and T cell cytokines by synovial fluid cells from children with juvenile rheumatoid arthritis.

The production of tumour necrosis factor-alpha (TNF-alpha), TNF-beta and IL-6 in synovial fluid was studied in 50 samples of synovial fluid from 44 children with juvenile rheumatoid arthritis (JRA) by identifying cytokine production at a single-cell level. Post Ficoll-separated synovial fluid mononuclear cells were permeabilized and then intracellular TNF-alpha, TNF-beta and IL-6 protein production was examined using indirect immunofluorescence and murine anti-cytokine MoAbs. All three cytokines were measured in 37 of the 50 samples. In 25 of the 37 samples there was complete concordance; all three cytokines were present in six and absent in 19 samples. At least one cytokine was present in 27/50 (54%) of synovial fluid samples. Overall, TNF-alpha was detected in 22/49 (45%) samples, TNF-beta in 15/41 (37%) and IL-6 in 16/45 (36%) samples. Five patients had serial arthrocentesis, and in these samples there were two patients who had initially positive cytokine production, which on subsequent measurement was negative; in the other three patients there was no change from the previous cytokine production. We provide evidence that synovial fluid mononuclear cells produce monocyte and T cell cytokines in JRA. These findings suggest a role for both T cell and macrophage products in the pathogenesis of JRA, and the potential for modulation of cytokine production as a target for therapeutic intervention.     

Regulation of IL-2 production by mononuclear cells from rheumatoid arthritis synovial fluids.

Products of polyamine oxidation down-regulate IL-2 production by peripheral blood T cells. We show here that the production of IL-2 by rheumatoid arthritis synovial fluid mononuclear cells is inversely correlated with the concentrations of polyamines in these cells. In addition, the inhibition of polyamine biosynthesis or oxidation in cultures of these cells enhances their ability to produce IL-2. Our findings suggest that polyamine oxidation plays an important role in the suppression of T cell function characteristic of rheumatoid arthritis synovial fluids.     

IDO/TTS色氨酸代谢途径对类风湿关节炎滑膜T细胞增殖的影响

自身反应性T细胞在类风湿关节炎(RA)疾病的发生发展中发挥着极其重要的作用,抑制这群细胞是RA治疗的关键.表达吲哚胺2,3-双加氧酶(indoleamine 2,3-dioxygenase,IDO)的树突状细胞(DC)能够通过此代谢通路剥夺环境中的色氨酸,并生成促凋亡因子犬尿氨酸等,使T细胞的增殖和功能受抑制,最终诱导...     

Functional characterization of SV40-transformed adherent synovial cells from rheumatoid arthritis.

A total of 14 transformed cell clones were obtained by micro-injecting origin-defective SV40 DNA into three types of cloned adherent synovial cells (ASC) (dendritic cells (DCs), macrophage-like cells (MCs), and fibroblast-like cells (FCs)) from two rheumatoid arthritis patients (five DC clones (SV40-DCs), five MC clones (SV40-MCs) and four FC clones (SV40-FCs)). All the transformed cell nuclei expressed SV40-specific T antigen. The cells which formed a colony had a few times shorter doubling time than the original cells. IL-1 alpha, IL-1 beta and prostaglandin E2 were detected in the culture supernatant from the unstimulated transformed cells like untransformed cells. The SV40-DCs showed the most potent accessory cell function in oxidative mitogenesis assay among the three types of SV40-ASCs. Granulocyte macrophage colony stimulatory factor (GM-CSF) was detected only in the culture supernatant from the SV40-MCs without stimulation. Extensive phenotypic analysis revealed relatively cell-specific markers. SV40-DCs were HLA-DP+ and glial fibrillary acidic protein positive. SV40-MCs stained positive for 5'-nucleotidase and nonspecific esterase. These transformed ASCs retained much of the original cellular physiology of rheumatoid arthritis (RA) ASCs and may be a useful tool for characterizing the role of ASCs in the pathogenesis of RA.     

FoxP3 mRNA splice forms in synovial CD4+ T cells in rheumatoid arthritis and psoriatic arthritis

Our aim was to elucidate the relative amount of the different splice forms of FoxP3 mRNA in CD4+ T cells in peripheral blood (PB) compared to synovial fluid (SF) in RA and PsA patients. FoxP3 mRNA was measured using a quantitative real-time PCR method. CD4+ T cells were isolated from 17 paired samples of PB and SF from RA and PsA patients, and PB from 10 controls. FoxP3fl and FoxP3Δ2 mRNA was significantly increased (6.7 and 2.1-fold, respectively) in PB CD4+ T cells from RA patients compared to controls. FoxP3fl and Δ2 mRNA in SF CD4+ T cells was increased compared to controls in sero-negative RA and PsA, but not in sero-positive RA patients, who had a high FoxP3 expression in both PB and SF. The FoxP3Δ2Δ7 mRNA was barely detectable in patient samples, and not at all in healthy individuals. We provide evidence of an increased expression of FoxP3 splice forms in synovial CD4+ T cells from RA patients. A skewed, high expression profile of FoxP3, but not CTLA-4, in sero-negative RA and PsA, indicates that synovial CD4+ T cells may represent unique subsets of T cells which have been induced locally or selectively recruited to the joint.     

Rheumatoid arthritis and the biological clock

Rheumatoid arthritis (RA) is an autoimmune disease of unknown cause and a chronic and progressive inflammatory disorder ensuing in genetically predisposed subjects, characterized by synovitis causing joint destruction, as well as inflammation in body organ systems, leading to anatomical alteration and functional disability. Immune competent cells, deregulated synoviocytes and cytokines play a key role in the pathophysiological mechanisms. The immune system function shows time-related variations related to the influence of the neuroendocrine system and driven by the circadian clock circuitry. Immune processes and symptom intensity in RA are characterized by oscillations during the day following a pattern of circadian rhythmicity. A cross-talk between inflammatory and circadian pathways is involved in RA pathogenesis and underlies the mutual actions of disruption of the circadian clock circuitry on immune system function as well as of inflammation on the function of the biological clock. Modulation of molecular processes and humoral factors mediating in RA the interplay between the biological clock and the immune response and underlying the rhythmic fluctuations of pathogenic processes and symptomatology could represent a promising therapeutic strategy in the future.     

Rheumatoid arthritis complicated by pachy- and leptomeningeal rheumatoid nodule-tike granulomas and systemic vasculitis

Rheumatoid nodule is a frequent and characteristic extra-articular manifestation of rheumatoid arthritis (RA). Its involvement of central nervous system is a rare occurrence with only a few reported cases. A 78-year-old man with severe arthritis showing the formation of rheumatoid nodule-like granulomas in the dura and subarachnoid space along with the spleen is presented. The characteristic morphological finding of the granulomas was the presence of neutrophlls and the absence of definite fibrinoid necrosis, which differed from the typical features of rheumatoid nodules previously described. The diagnosis should be based on the exclusion of diseases that may cause similar granulomatous reactions including infectious diseases. Additionally, there was systemic necrotizing vasculitis in the dura and multiple cerebral Infarcts, although the association between vasculitis and cerebral infarcts was not clear.     

Lack of T cell oligoclonality in enzyme-digested synovial tissue and in synovial fluid in most patients with rheumatoid arthritis.

The dominant presence of specific T-cell populations in the rheumatoid joint as detected by Southern blot analysis of T cell receptor (TCR) gene rearrangements would indicate local antigen recognition and T cell proliferation. We therefore studied TCR beta chain gene rearrangements using a C beta 2 probe in paired samples of T cell populations from synovial tissue and peripheral blood (n = 6) as well as synovial fluid (n = 16) and peripheral blood (n = 18) of patients with rheumatoid arthritis (RA). Peripheral blood mononuclear cells from healthy donors (n = 7) served as a control. T cells were studied directly after isolation or after non-specific expansion with OKT3 monoclonal antibody (MoAb) and T cell growth factor (TCGF). DNA samples were digested with EcoRI and HindIII to detect rearrangements to C beta 1 and C beta 2, respectively. Extra bands were detected in all EcoRI-digested DNA samples prepared from both freshly isolated and non-specifically expanded T cell populations of patients and healthy donors, possibly representing 'common' (V-) D-J rearrangements. Dominant rearrangements were found in only two out of 16 synovial fluid T cell populations (one freshly isolated and one expanded) and not in peripheral blood or synovial tissue derived T cell populations. No extra bands were detected in HindIII-digested DNA samples. To investigate the effect of in vitro culture techniques on rearrangement patterns we studied DNA samples prepared from synovial tissue T cells obtained both by outgrowth from tissue with TCGF or by enzyme digestion and subsequent expansion either with TCGF or with OKT3 MoAb and TCGF. Whereas the latter T cell population yielded 'common' rearrangements, the former T cell populations yielded different dominant rearrangements. These data indicate that oligoclonality of the T cell populations in synovial tissue and synovial fluid of patients with RA is a rare event. The data also show the influence of in vitro culture techniques on the result of TCR gene rearrangement analysis.     

Expansion of a unique macrophage subset in rheumatoid arthritis synovial lining layer

The Z39Ig protein (complement receptor for C3b and iC3b) is expressed on resident tissue macrophages in various tissues. This study was undertaken to examine the distribution of Z39Ig+cells and their phenotypic features in rheumatoid arthritis (RA) synovium, in comparison with those of osteoarthritis (OA) and psoriatic arthritis (PsA) synovium. Monoclonal anti-Z39Ig antibody was produced by immunizing Z39Ig transfected murine pre B cells and used for the identification of Z39Ig+cells. Z39Ig+cells were further stained with antibodies to macrophages, fibroblast-like synoviocytes, complement receptors and dendritic cells by using the double immunostaining method in normal, RA, OA and PsA synovium. RA synovial mononuclear cells were double-stained using anti-Z39Ig and anti-CD11c antibodies and sorted into Z39Ig+CD11c+cells and Z39Ig+CD11c-cells. These cell populations were then analysed by electron microscopy. The expression of the Z39Ig protein was limited to intimal macrophages in normal, RA, OA and PsA synovium. The numbers of Z39Ig+CD11c+cells and the ratios of Z39Ig+CD11c+cells to Z39Ig+cells were increased in the synovial lining layer of RA as compared with those of OA and PsA. The ultrastructural analysis of Z39Ig+CD11c+cells showed the character of macrophages with many secondary lysosomes and swelling of mitochondria. Z39Ig+ cells appeared to be useful for identification of resident tissue macrophages in normal synovium and the corresponding macrophages in the synovial lining layer of inflammatory arthritis. Expansion of Z39Ig+CD11c+cells was characteristic of RA synovial lining layer.