霉酚酸对系统性红斑狼疮患者外周血单个核细胞细胞因子分泌及Th亚群的影响

目的研究霉酚酸（mycophenolic acid,MPA）对系统性红斑狼疮（systemic lupus erythematosus,SLE）患者外周血单个核细胞（PBMCs）细胞因子分泌及Th细胞亚群的作用。方法分离SLE患者及健康对照的外周血单个核细胞（PBMCs）,加入MPA或对照药物地塞米松（DEX）培养48h,用ELISA法测培养上清中IL-10、IL-12及IFN-γ的水平,用三色流式细胞术检测培养细胞中CD4^＋IFN-γ^＋IL-10^-T细胞、CD4^＋IFN-γ^-IL-10^＋T细胞及CD4^＋IFN-γ^＋IL-10^＋T细胞百分率。结果①MPA可使SLE患者PBMCs培养上清中IL-10、IL-12及IFN-γ的分泌显著降低,而DEX却使IL-10分泌水平增高。②MPA可降低SLE患者培养的PBMCs中CD4^＋IFN-γ^＋IL-10^-T、CD4^＋IFN-γ^-IL-10^＋T及CD4^＋IFN-γ^＋IL-10^＋T细胞比率,而DEX在使CD4^＋IFN-γ^＋IL-10^＋T细胞亚群比率增高的同时,却使CD4^＋IFN-γ^＋IL-10^-T细胞亚群的比率降低。结论MPA可抑制SLE患者PBMCs细胞因子分泌,并降低SLE患者外周血培养的PBMCs中Th亚群比率。     

CD4+CD25+调节性T细胞在母-胎免疫耐受中的作用

CD4^＋CD25^＋调节性T细胞（Regulatory T cell，Treg）是最近被人们认识的一类重要的具有免疫调节功能的T细胞亚群，其功能障碍可能与自身免疫性疾病密切相关；并且参与维持外周T细胞内环境稳定；在移植耐受中其也起着关键作用。近年研究发现，在妊娠的各个时期，母体外周血、     

Th17细胞的研究进展

CD4^＋T细胞在免疫防御中起了核心的作用。迄今为止已经证明至少存在4种不同的CD4^＋T细胞亚群——Th1、Th2、Th17和调节性T细胞（Treg）。其中,Th17细胞是最近研究发现的一种新型的CD4^＋效应T细胞,该细胞是由天然T细胞前体分化而来,具有独立的分化和发育调节机制,并产生特征性的IL-17效应因子,在自身免疫性、感染性疾病和移植排斥中发挥重要的作用。然而,关于Th17介导的免疫反应的调控以及Th17细胞与其它T细胞亚群的相互作用等许多有趣的疑问尚需解答。     

Th17细胞及IL-17与系统性红斑狼疮

系统性红斑狼疮（SLE）是多种因素相互作用引起的自身免疫性疾病,其发病机制复杂。Th17细胞是最近发现的CD4^＋效应T细胞的新亚群。初始T细胞在TGF—B和IL-6的共同作用下分化发育成为Th17细胞,后者可以分泌IL-17、IL-21、IL-22等多种细胞因子。其中IL-17在多种自身免疫疾病（比如类风湿关节炎和Crohn’s病）中起关键作用,但在SLE中的作用尚不清晰。     

介导CD4+CD25+调节性T细胞发育与功能的一个关键基因--Foxp3

CD4^＋CD25^＋调节性T细胞是天然产生的调节性T细胞的重要亚群之一，在维持免疫系统稳态中发挥重要的作用。目前有关CD4^＋CD25^＋调节性T细胞分化发育的确切机制还不清楚。最近的研究发现Foxp3基因与CD4^＋CD25^＋调节性T细胞的分化发育和免疫调节功能的关系密切，进而提示Foxp3可能是CD4^＋CD25^＋调节性T细胞的一个特征性标志。     

IL-4、IL-10和抗IL-12受体β1 mAb抑制IL-23诱导正常人记忆T细胞 IFN-γ产生

目的 探讨重组人白介素23（IL-23）是否能够诱导正常人T细胞IFN-γ的产生,作用的靶细胞亚群和调节因素。方法 正常人PBMC在抗CD3（anti-CD3）单克隆抗体或anti-CD3和抗CD28（anti-CD28）单克隆抗体刺激的条件下与IL-23进行培养,采用酶联免疫吸附试验（ELISA）检测细胞培养液中IFN-γ的水平;同时采用流式细胞仪,在单个细胞水平上分析IL-23诱导PBMC IFN-γ表达的T细胞亚群。结果 在未经任何刺激的情况下,PBMC产生很低或不产生IFN-γ。IL-23呈剂量依赖方式促进由anti-CD3活化的PBMC IFN-γ产生。细胞亚群分析的结果表明,IL-23诱导记忆CD4^＋和CD8^＋T细胞表达IFN-γ,对活化的CD4^＋T细胞作用较为明显。Th2细胞因子（IL-4、IL-10）和抗IL-12受体β1 mAb（IL-12Rβ1）抑制IL-23诱导T细胞IFN-γ产生。结论 IL-23促进活化的记忆CD4^＋和CD8^＋T细胞IFN-γ的产生。Th2细胞因子和抗IL-12Rβ1 mAb抑制由IL-23诱导IFN-γ产生,提示这些细胞因子和抗体对IL-23引起的自身免疫病具有拮抗作用。     

肺炎支原体肺炎患儿外周血T淋巴细胞表面IL-18Rα的变化及意义

目的：探讨肺炎支原体肺炎（MPP）患儿外周血T淋巴细胞表面IL-18Rα表达的意义。方法：采用流式细胞术测定35例MPP患儿外周血T淋巴细胞亚群（CD3/CD4/CD8）和T淋巴细胞表面IL-18Rα的表达水平,并与正常对照组比较。结果：MPP患儿T细胞亚群与正常对照相比,CD3^＋细胞百分率降低（P〈0.05）,51.4%的MPP患儿CD4^＋/CD8^＋在1.0-1.9的范围之外。急性期MPP组CD4^＋T和CD8^＋T淋巴细胞表面IL-18Rα的表达较正常对照组明显升高,有显著性差异（P〈0.01）;恢复期与对照组比较有显著性差异（P〈0.05）。恢复期表达水平下降,与急性期比较有显著性差异（P〈0.05）。T细胞亚群异常组与正常组相比,CD4^＋T和CD8^＋T细胞IL-18Rα表达明显增高（P〈0.01）,T细胞亚群正常组与正常对照无明显差别（P〉0.05）。结论：MPP患儿存在细胞免疫功能紊乱,外周血T淋巴细胞存在Th1/Th2失衡,急性期表现为Th1优势应答。     

移植免疫耐受中调节性T细胞的研究进展

调节性T细胞（Tr）在诱导和维持移植免疫耐受过程中的作用越来越受到人们的重视。根据不同的细胞表型和功能已将Tr分为若干亚类，首先是胸腺内T细胞发育过程中自然产生的CD4^＋T细胞亚群，能够构成性表达IL-2受体的仅链（CD25）存在于外周，体内体外均可抑制效应性T细胞的增殖和功能；其次是产生于正常的免疫应答过程中的诱导性Tr亚群，包括Tr1和Th3通过分泌细胞因子如IL-10和TGF—β发挥抑制作用。除此之外，也有报道CD8^＋Tr、双阴性T（DNT）细胞和NKT细胞在移植耐受的不同模型中亦发挥重要作用。因而研究各种Tr亚群的生物学特征、调节机制及其在移植耐受中的作用非常必要。     

CD4+CD25+调节T细胞在免疫耐受及自身免疫病中的作用

越来越多的研究表明调节T细胞是外周免疫耐受的关键。CD4^＋CD25^＋调节T细胞在免疫耐受、自身免疫病、移植、肿瘤等方面均有着极其重要的作用,并需要TGF-β参与。在很多自身免疫性疾病如SLE、炎症性肠病中,CD4^＋CD25^＋调节T细胞的数量和,或功能存在显著异常,且多与疾病活动正相关。通过对自身免疫病外周血T细胞亚群进行修饰再自体回输可能是治疗这类疾病新的突破。     

IL-21在Th17细胞炎症反应中的作用

Th17细胞是新近发现的T淋巴细胞亚群.作为不同于Th1、Th2的细胞亚群,已经被证实在自身免疫病、感染、炎症等疾病中发挥重要作用.IL-21作为Th17细胞的自分泌调节因子,在Th17细胞功能的维持、抑制Th1、调节性T细胞(Treg)分化等方面发挥关键作用.Th17细胞能够自分泌产生IL-21,从而促进自身分化过程...     

Induction of peripheral blood T follicular helper cells expressing ICOS correlates with antibody response to hepatitis B vaccination

T follicular helper (TFH) cells, a critical subset of CD4⁺ T cells, provide help to B cells during the procession of the humoral immune response in the germinal center (GC) and extrafollicular sites. CXCR5⁺CD4⁺ T cells in human circulating blood, referred to herein as peripheral TFH (pTFH) cells, share phenotypes and functional properties with TFH cells in GC. Hepatitis B vaccine protects about 60% of the chronic hepatitis C patients from hepatitis B. The immunological bases that lead to the induction of protective antibody response is not well understood. In the present study, the pTFH cells subsets were determined in 18 healthy controls (anti-HBs ≥ 100 mIU/mL; HC), 21 nonresponders (anti-HBs < 10 mIU/mL; NR), and 23 weak responders (10 mIU/mL ≤ anti-HBs < 100 mIU/mL; WR) of chronic hepatitis patients upon routine hepatitis B vaccination. Though the frequency of the pTFH cell was equivalent in HC, WR, and NR, ICOS⁺pTFH cells in HC underwent expansion with increased IL-21 secretion and production of serum anti-HBs response at 4 weeks after a full course of hepatitis B vaccination. These changes were not shown in both NR and WR. Analysis of ICOS⁺pTFH cells represents a novel cellular determinant of the hepatitis B vaccine–induced humoral immune response, which may have relevance for design of hepatitis B vaccine.     

Regulation of T follicular helper cell formation and function by antigen presenting cells

CD4+ T cells can differentiate into numerous subsets characterized by expression of a suite of cytokines and effector molecules that endow them with specialized functions. By mediating the differentiation of B cells into memory and plasma cells following exposure to T-dependent antigens (Ag), T follicular helper (TFH) cells have emerged as the predominant subset of CD4+ T cells responsible for regulating humoral immunity. The generation of TFH cells from na?ve precursors typically involves sequential cognate interactions with distinct populations of Ag-presenting cells (APCs): dendritic cells within the T-cell zone of lymphoid tissues, and activated B cells at the border of the T-zone and follicle, and then within a germinal center. Recent studies have illuminated the key roles of APCs in TFH development, and have also re-defined the role of B cells in this process.     

IL-21在滤泡辅助性T细胞分化发育及功能中的作用

抗原刺激B细胞产生抗体需要T细胞辅助,近年来人们逐渐认识到一个命名为滤泡辅助性T细胞（Tfh）的CD4^＋T细胞亚群在B细胞诱导的免疫应答中具有重要作用。Tfh细胞的主要特征包括表达趋化因子受体与（CXCR5）,迁移定位于B细胞滤泡辅助B细胞产生抗体。Tfh细胞产生的细胞因子IL-21能够促进B细胞分化为抗体形成细胞,这种辅助性细胞因子在Tfh细胞的分化发育、效应发挥及Tfh细胞功能失调相关的疾病中具有重要意义。     

IL-21在滤泡辅助性T细胞分化发育及功能中的作用

抗原刺激B细胞产生抗体需要T细胞辅助,近年来人们逐渐认识到一个命名为滤泡辅助性T细胞(Tfh)的CD4+T细胞亚群在B细胞诱导的免疫应答中具有重要作用.Tfh细胞的主要特征包括表达趋化因子受体与(CXCR5),迁移定位于B细胞滤泡辅助B细胞产生抗体.Tfh细胞产生的细胞因子IL-21能够促进B细胞分化为抗体形成细胞,这种辅助性细胞因子在Tfh细胞的分化发育、效应发挥及Tfh细胞功能失调相关的疾病中具有重要意义.     

Combined immunodeficiency due to the selective absence of CD4 inducer T lymphocytes

Selective congenital deficiency of the CD4 inducer T lymphocyte subset is a recently described variant of combined immunodeficiency. To further characterize the cellular and molecular mechanisms which lead to the profound T and B cell immunodeficiency in this condition, we examined in vitro immunoregulatory T lymphocyte activation and effector function, interleukin-2 (IL-2) synthesis, IL-2 receptor generation, and CD4 gene structure. Immunophenotyping of T lymphocytes demonstrated a selective deficiency of CD4+ cells, with normal numbers of CD2+ and CD3+ T cells, nearly all of which expressed the CD8+ determinant. Mitogen- and alloantigen-induced blastogenesis was profoundly decreased. B lymphocytes were present in normal numbers but there was a functional dysgammaglobulinemia (low IgG, normal IgM, low IgA) with no antibody response to in vivo immunization. T cells from the patient did not provide help to normal B cells for in vitro immunoglobulin synthesis; however, the patient's B cells were capable of synthesizing normal amounts of IgG when provided help from normal T cells. Concanavalin A failed to activate suppressor-inducer function in the patient's T cells. However, CD8+ T cell-mediated suppression was expressed if the patients T cells were cocultured with normal CD4+ T cells in a pokeweed mitogen-stimulated IgG secretion assay. IL-2 secretion and IL-2 receptor expression were both markedly reduced. Southern blot analysis of genomic DNA revealed no obvious abnormality in CD4 gene structure. The global defects in T cell activation, effector function, immunoregulation, and lymphokine generation observed in CD4+ inducer lymphocyte deficiency emphasizes the central role that the CD4 T lymphocyte plays in the activation and regulation in vivo immune responses.     

Higher frequencies of circulating ICOS+, IL-21+ T follicular helper cells and plasma cells in patients with new-onset membranous nephropathy

Background: T follicular helper (TFH) cells and B cells are known to regulate humoral immune responses. This study is aimed at examining the putative contribution of different subsets of circulating of TFH cells and B cells to membranous nephropathy (MN).

Methods: A total of 45?MN patients and 19 healthy controls (HCs) were examined for the number of TFH cells and B cells by flow cytometry. The level of 24-h urinary protein and eGFR were calculated, and the level of serum cytokines was examined. The potential association among these measures was analyzed.

Results: Compared to the HCs, MN patients had significantly higher numbers of circulating CD4⁺CXCR5⁺, CD4⁺CXCR5⁺ICOS⁺, CD4⁺CXCR5⁺CD154⁺, CD4⁺CXCR5⁺IL-21⁺, and CD4⁺CXCR5⁺CD28⁺ TFH cells, as well as IgD⁺CD27^?CD19⁺ and CD138⁺CD19⁺ B cells. However, the number of IgD⁺CD27⁺CD19⁺ B cells was significantly lower in MN patients than in the HC. The levels of serum IL-21, IL-2, IL-4, IL-10, IL-17A, and IFN-γ were significantly higher in MN patients than in the HC. Furthermore, the numbers of CD4⁺CXCR5⁺, CD4⁺CXCR5⁺ICOS⁺, CD4⁺CXCR5⁺CD154⁺, CD4⁺CXCR5⁺IL-21⁺, CD4⁺CXCR5⁺CD28⁺ TFH cells, CD138⁺CD19⁺ B cells, and the level of sera IL-21 were negatively correlated with the values of eGFR, but positively correlated with the levels of 24-h urinary proteins. Following treatment, the numbers of CD4⁺CXCR5⁺, CD4⁺CXCR5⁺ICOS⁺, CD4⁺CXCR5⁺CD154⁺, CD4⁺CXCR5⁺IL-21⁺, CD4⁺CXCR5⁺CD28⁺ TFH cells, CD138⁺CD19⁺ B cells, and the levels of IL-21 were significantly reduced. In contrast, IL-4 and IL-10 levels were noticeably increased after treatment.

Conclusions: Data suggest that activated TFH and plasma cells may contribute to the pathogenesis of MN.