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.     

Activation of murine dendritic cells and macrophages induced by Salmonella enterica serovar Typhimurium

Macrophages and dendritic cells (DCs) are antigen-presenting cells (APCs), and the direct involvement of both cell types in the immune response to Salmonella has been identified. In this study we analysed the phenotypic and functional changes that take place in murine macrophages and DCs in response to live and heat-killed Salmonella enterica serovar Typhimurium. Both types of cell secreted proinflammatory cytokines and nitric oxide (NO) in response to live and heat-killed salmonellae. Bacterial stimulation also resulted in up-regulation of costimulatory molecules on macrophages and DCs. The expression of major histocompatibility complex (MHC) class II molecules by macrophages and DCs was differentially regulated by interferon (IFN)-gamma and salmonellae. Live and heat-killed salmonellae as well as lipopolysaccharide (LPS) inhibited the up-regulation of MHC class II expression induced by IFN-gamma on macrophages but not on DCs. Macrophages as well as DCs presented Salmonella-derived antigen to CD4 T cells, although DCs were much more efficient than macrophages at stimulating CD4 T-cell cytokine release. Macrophages are effective in the uptake and killing of bacteria whilst DCs specialize in antigen presentation. This study showed that the viability of salmonellae was not essential for activation of APCs but, unlike live bacteria, prolonged contact with heat-killed bacteria was necessary to obtain maximal expression of the activation markers studied.     

Engulfment of mast cell secretory granules on skin inflammation boosts dendritic cell migration and priming efficiency

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B7-H3单抗交联作用对Mo-DC体外生物学功能的影响

探讨B7-H3分子对人外周血单核细胞来源树突状细胞(Mo-DC)体外成熟和生物学功能的影响。采用常规方法从健康人外周血单核细胞诱导DC,在诱导过程中,加入B7-H3单抗21D4共培养,经流式细胞术检测Mo-DC上B7-H3分子和其他共刺激分子的表达,ELISA试剂盒检测培养上清中细胞因子IL-10和IFN-γ的分泌量,并采用3H-TdR掺入法测定T细胞的增殖。结果:B7-H3分子在未成熟和成熟Mo-DC上均有高水平表达,抗人B7-H3单抗21D4能上调Mo-DC表面CD80、CD86和CD83的表达,提高Mo-DC的共刺激能力,促进T细胞的体外增殖,并能显著促进T细胞分泌IL-10。由此表明,B7-H3单抗21D4交联作用可以促进Mo-DC体外成熟,上调其共刺激T细胞的能力。     

Immunopathological features of palatine tonsil characteristic of IgA nephropathy: IgA1 localization in follicular dendritic cells

IgA nephropathy (IgAN) is generally thought to be mediated by the glomerular deposition of circulating immune complexes containing IgA as the major antibody component. Upper respiratory infections and tonsillitis often precede IgAN. and in some cases tonsillectomy is affective for the (treatment of IgAN. Thus, the tonsil seems to be a unique organ causing initial and/or progressive events to generate nephritogenic immune complexes in IgAN. in this study we focused on the analysis of immunopathological features of the palatine tonsil characteristic of IgAN patients by using an immunohistochemical technique. The IgAl subclass was demonstrated in follicular dendritic cells (FDC) of the tonsil of IgAN patients, but not in FDC of non-IgAN controls. On the other hand, IgA2, IgG, IgM and C3 did not show any differences in distribution between the two groups. Moreover, the expression of decay-accelerating factor (DAF), an inhibitor of homologous complement activation, and transforming growth factor-beta I (TGF-/β1). an inducer of antibody-producing ceils to IgA class switching, in FDC and interdigitating dendritic cells of the tonsil, respectively, which was also clarified in this study for the first time, was found to be identically distributed in the two groups. These findings may support the idea that IgA1. possibly in an immune complex form, is trapped by FDC and plays an important role in the persistent activation of particular B cell repertoires responsible for ihe onset and/or progression of IgAN.     

EB病毒LMP2A特异性CTL的体外诱导及分析

用EBV LMP2A重组痘苗病毒 (rVV LMP2A )转染人树突状细胞 (DC ) ,转染后的DC分别在第 1、 7、 14天刺激相同MHC背景的T细胞 ,在IL 2作用下诱导LMP2A特异性CTL。用LDH释放法检测CTL杀伤活性 ;流式细胞术 (FACS )检测CTL诱导分化过程中CD3+ 、CD4 + 、CD8+ 、CD5 6 + 等细胞的分群变化 ;RT PCR检测细胞分化过程中FasLmRNA表达 ;生物活性法检测功能性细胞因子IFN γ的分泌。结果显示本法诱导的CTL对靶细胞有特异性杀伤活性 ,第 2次和第 3次DC刺激后杀伤活性有所上升 ;在CTL诱导分化的第 7、 14、 2 1天细胞分群以CD4 + 、CD8+ 细胞为主 ;RT PCR证实所诱导的细胞内有FasLmRNA的表达 ;随细胞培养天数的增加IFN γ分泌增加 ,在第 14天达到较高水平。研究表明重组痘苗病毒载体rVV LMP2A转染的DC刺激T细胞可诱导出EBV LMP2A特异性CTL。     

G-CSF对外周血树突状细胞亚群比例的影响

目的 :了解G CSF对小鼠外周血树突状细胞 (DC)亚群比例的影响。方法 :以不同剂量 (0、5 .0、10 .0或 15 .0 μg)的G CSF ,分别皮下注射于BALB/c小鼠 ,连续 6d ,每天 1次。第 6天分离外周血DC ,用流式细胞仪检测DC1(CD11c+ CD8a-)和DC2 (CD11c+ CD8a+ )的比例并计算其绝对值。结果 :经不同剂量的G CSF刺激后 ,外周血DC1的绝对值无显著变化 ,而DC2的绝对值增加 5倍 (9.6× 10 6/Lvs 5 5 .1× 10 6/L ,P <0 .0 1) ,DC1/DC2比值降低 (4.2vs 0 .7,P <0 .0 1)。结论 :G CSF在体内可提高外周血DC2的绝对数 ,对DC1的数无明显影响 ,从而使DC1/DC2的比例倒置     

Cells with dendritic morphology and bright interleukin-1 alpha staining circulate in the blood of patients with rheumatoid arthritis.

Freshly isolated peripheral blood mononuclear cells (PBMC) from 10 healthy volunteers, 28 patients with rheumatoid arthritis (RA), eight patients with osteoarthritis, and five patients with ankylosing spondylitis were examined for interleukin-1 alpha (IL-1 alpha) and interleukin-1 beta (IL-1 beta) production using monoclonal antibodies and an indirect immunofluorescent method. In freshly isolated PBMC from healthy controls very few cells were stained for either IL-1 type. All 20 RA patients who were not receiving parenteral gold therapy had PBMC staining for IL-1 alpha. In these patients, up to 7.5% of PBMC showed bright IL-1 alpha staining (range 1.2-7.5%). No IL-1 beta staining was seen. These IL-1 alpha-staining cells had a dendritic morphology and the percentage of cells staining correlated well with levels of C-reactive protein, an index of disease activity in these RA patients. Significantly fewer IL-1 alpha-staining cells were present in the peripheral blood of RA patients receiving gold therapy and in the blood of patients with osteoarthritis and ankylosing spondylitis. These IL-1 alpha-containing cells, circulating in the blood of RA patients and correlating with disease activity have not been previously described. These results support the idea that IL-1 alpha plays an important role in the pathogenesis of rheumatoid inflammation.     

大鼠腘窝淋巴结内淋巴滤泡的生后发育

目的:研究大鼠淋巴结淋巴滤泡的生后发育.方法:采用常规组织学、免疫细胞化学及三维重建技术研究了大鼠腘窝淋巴结内淋巴滤泡的发生.结果:生后18天始,淋巴结浅层皮质内sIgM阳性B淋巴细胞聚集形成初级淋巴滤泡.生后3周ED-5阳性滤泡树突状细胞出现.随着鼠龄及体重的增长,初级淋巴滤泡不断扩大,每个淋巴结内淋巴滤泡数亦增多.生后13周滤泡数达高峰,平均每个淋巴结86个,13周以后体重缓慢增长,淋巴滤泡数逐渐下降.生后8周时,次级淋巴滤泡出现,ED-5阳性滤泡树突状细胞主要分布于亮区.结论:初级淋巴滤泡形成过程中B淋巴细胞聚集可能诱导局部网状细胞分化成滤泡树突状细胞;发育期间淋巴滤泡数随体重增长而增加可能与某些决定机体生长的因素作用有关.