Role Of Cytokines In The Pathogenesis And Treatment Of A

细胞因子在 A 的发病机制和治疗中的作用

• 批准号: 6808556
• 负责人: ETHAN M. SHEVACH
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF ALLERGY AND INFECTIOUS DISEASES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6808556
• 关键词: autoimmune disorder; cell differentiation; cytokine; cytokine receptors; enzyme linked immunosorbent assay; flow cytometry; genetically modified animals; helper T lymphocyte; immunoregulation; immunotherapy; interferon gamma; interleukin 10; interleukin 12; interleukin 4; laboratory mouse; transforming growth factors

Studies in infectious disease and autoimmunity models have shown that immune responses to both self and foreign antigens are frequently dominated by induction of a particular Th1/Th2 subset with profound consequences for clinical outcome. Although the inflammatory effector function of Th1 cells is essential for the clearance of intracellular pathogens, it is also responsible for the tissue damage typical of organ-specific autoimmunity. Th2 cells which play an important role in the clearance of many helminthic infections function as suppressor cells or ineffectual bystanders in organ-specific autoimmune diseases. We have focused our efforts on identification of the cytokines that play critical roles in the induction of Th1 and Th2 responses. Previous studies have suggested that activation of CD4+ T cells in the presence of IL-10 results in the generation of or a population of T cells, termed T regulatory 1 (Tr1) cells, that primarily produce IL-10 and TGF-beta, but not IL-4. The relationship between Tr1 cells and conventional Th2 cells remains unclear. We have not been successful in our attempts to generate significant numbers of antigen-specific t cells that secreted IL-10, but not IL-4, by performing cultures in the presence of IL-10 alone. The small numbers of cells that produced IL-10 only were completely dependent on the presence of IL-4 and signal transducer and activator of transcription 6 for their generation. Studies with myelin basic protein-specific T cells derived from an IL-4 deficient mouse confirmed the absolute requirement for the generation of IL-10 producers under all culture conditions. These IL-10 producing Th2 cells failed to inhibit experimental allergic encephalomyelitis (EAE) in an adoptive transfer model and were pathogenic when transferred to immunodeficient mice. These studies raise doubts about the existence of a unique population of CD4+ regulatory T cells that can be generated in the presence of IL-10. Myelin oligodendrocyte glycoprotein (MOG) represents an important target autoantigen in multiple sclerosis and in EAE in animals. We have generated a T cell receptor (TCR) transgenic (Tg) mouse expressing a TCR derived from an encephalotigenic T cell clone specific for MOG 35-55. This TCR Tg line failed to develop EAE spontaneously and only developed mild EAE at late onset even when immunized with MOG in adjuvant. The TCR Tg T cells produced large amounts of IL-4 when stimulated in vitro with MOG in the absence of exogenous IL-4 and underwent FAS/FAS-L mediated activation induced cell death when stimulated with MOG in the presence of IL-12. this phenotype was acquired in the periphery and not during T cell differentiation in the thymus and was not secondary to the presence of regulatory T cells. The unique phenotype of these autoantigen-specific T cells may represent an important mechanism of protection against autoimmune disease. TGF-beta, a pleiotropic cytokine that has multiple effects on immune responses, has been shown to inhibit IL-4/GATA-3 expression as well as Th2 differentiation. Consistent with these reports, we found that priming T cells from DO11.10 transgenic mice with antigen in the presence of TGF-beta inhibited GATA-3 expression and the development of IL-4-producing T cells. Unexpectedly, the inhibition of Th2 development was accompanied by a substantial increase in the number of IFN-gamma-producing cells. T cells primed with TGF-beta secreted IFN-gamma in response to both TCR ligation and IL-12/IL-18 stimulation, and expressed high levels of T-bet and low levels of GATA-3. The TGF-beta mediated enhancement of Th1 priming was independent of IL-12 and STAT-4, but required endogenous IFN-gamma. The TGF-beta-mediated enhancement of the IFN-gamma dependent, IL-12-independent pathway of Th1 priming was mediated primarily by the inhibition of the production of IL-4 by memory/activated T cells in the unfractionated CD4+ responder population. Nevertheless, TGF-beta did not inhibit this pathway of Th1 differentiation when naive CD4+ T cells were used as responders. These data have important implications for strategies being considered for the use of TGF-beta producing T cells for the treatment of autoimmune disorders.

在传染病和自身免疫模型中的研究表明，对自我和外国抗原的免疫反应经常通过诱导特定的TH1/TH2子集而主导，对临床结果产生了深远的影响。尽管Th1细胞的炎症效应功能对于清除细胞内病原体至关重要，但它也负责典型的器官特异性自身免疫性的组织损伤。在清除许多蠕虫感染中起着重要作用的Th2细胞在器官特异性自身免疫性疾病中充当抑制细胞或无效旁观者。我们将精力集中在鉴定细胞因子中，这些细胞因子在诱导Th1和Th2反应中起着关键作用。先前的研究表明，在存在IL-10的情况下，CD4+ T细胞的激活导致T细胞的产生或群体，称为T调节1（TR1）细胞，主要产生IL-10和TGF-beta，而不是IL-4。 TR1细胞与常规TH2细胞之间的关系尚不清楚。我们并没有成功地通过仅在IL-10存在下进行培养物来产生大量分泌IL-10而不是IL-4的抗原特异性T细胞。产生IL-10的少数细胞仅完全取决于其产生的IL-4和信号传感器和转录6的激活因子的存在。 源自IL-4缺乏小鼠的髓磷脂碱性蛋白特异性T细胞的研究证实了在所有培养条件下生成IL-10生产者的绝对需求。这些产生Th2细胞的IL-10未能抑制过过敏性转移模型中的实验过敏性脑脊髓炎（EAE），并且当转移到免疫缺陷小鼠中时具有致病性。这些研究引起了人们对在IL-10存在下可以生成的CD4+调节T细胞的独特群体的怀疑。髓磷脂少突胶质细胞糖蛋白（MOG）代表多发性硬化症和EAE中的重要靶靶自身抗原。我们已经产生了一种T细胞受体（TCR）转基因（TG）小鼠，该小鼠表达了TCR，该TCR源自MOG 35-55特异的脑食难生性T细胞克隆。这条TCR TG系列未能自发发展，即使在佐剂中用MOG进行免疫时，也只能在发病迟到时出现轻度的EAE。当在没有外源性IL-4的情况下用MOG刺激MOG刺激TCR TG T细胞在IL-12的存在下用MOG刺激MOG时，在体外用MOG刺激了大量IL-4。该表型是在胸腺中的外围的，而不是在T细胞分化期间获得的，不是继发调节性T细胞的继发。这些自身抗原特异性T细胞的独特表型可能代表了保护自身免疫性疾病的重要机制。 TGF-β是一种对免疫反应有多种影响的多效细胞因子，已显示可抑制IL-4/GATA-3表达以及TH2分化。与这些报道一致，我们发现在TGF-β存在下，DO11.10转基因小鼠的T细胞抑制了GATA-3的表达，并发育IL-4产生的T细胞。出乎意料的是，对Th2发育的抑制作用伴随着产生IFN-gamma的细胞数量的大幅增加。用TGF-beta启动的T细胞响应TCR连接和IL-12/IL-18刺激，并表达高水平的T-bet和低水平的GATA-3。 TGF-β介导的Th1启动的增强与IL-12和STAT-4无关，但需要内源性IFN-GAMMA。 TGF-beta介导的IFN-γ依赖性，Th1启动的IL-12独立途径的增强主要是通过未质量的CD4+响应者种群中记忆/活化的T细胞抑制IL-4的产生IL-4的介导的。然而，当将幼稚的CD4+ T细胞用作响应者时，TGF-beta并未抑制Th1分化的途径。这些数据对考虑使用TGF-β产生T细胞来治疗自身免疫性疾病的策略具有重要意义。