Aberrant T Cell Function and Immunopathogenesis of CMV Immune Recovery Uveitis

描述(申请人提供)：在艾滋病和巨细胞病毒视网膜炎(CMVR)患者中，通过抗逆转录病毒治疗获得免疫储存，并可以停止抗CMV治疗而不会进一步发展视网膜炎，出现了一个导致视力障碍的新原因--免疫恢复性葡萄膜炎(IRU)。本研究的目的是探讨T细胞功能异常在CMV IRU免疫发病机制中的作用。我们建议用自身免疫性葡萄膜炎和感染后葡萄膜炎的动物模型来检验以下假设：1)CMV特异性的CD4+和CD8+T细胞细胞因子反应之间的失衡和/或调节性CD4+T细胞(Treg)缺陷在CMV IRU患者的PBMC中比免疫储存的未发生IRU的CMVR患者中更常见；2)用流式细胞仪测量这种异常的T细胞反应可能具有潜在的临床实用价值，作为一种筛查试验，以确定免疫储存的CMVR患者发生IRU的风险。这项建议采用病例对照设计。已经在NEI赞助的多中心CMVR自然历史观察研究中收集的储存的PBMC将被解冻，并通过流式细胞术检测CMV特异性的CD4+T细胞IL-2和CD8+T细胞干扰素？、TNFa和CD107a/b的反应和Treg含量。检测结果将比较病例和匹配对照组的结果，这些病例和匹配的对照组都被诊断为艾滋病和CMVR，并通过抗逆转录病毒治疗进行了免疫存储，在父母的纵向研究中，谁(病例)或没有(对照组)被诊断为IRU。为了了解Treg功能在病例和对照中影响CMV特异性CD8+T细胞效应的机制，我们还将研究去除PBMC中的Treg和向去除Treg的PBMC中添加回流分选的Treg细胞对CMV特异性和抗CD3诱导的CD8+T细胞功能反应的影响。在后面的实验中，抗IL-10和/或抗转化生长因子抗体也将被用来测试CMV特异性CD8+T细胞反应的调节是否依赖于这些细胞因子。巨细胞病毒视网膜炎(CMVR)在美国和欧洲仍然是艾滋病的重要并发症，在国际上，特别是在亚洲，正在成为艾滋病的重要并发症。在美国，巨细胞病毒免疫恢复性葡萄膜炎(IRU)现在占长期存在CMVR和抗逆转录病毒治疗介导的免疫恢复的艾滋病患者视力丧失的50%。目前还没有有效的治疗CMV IRU的方法。因此，了解CMV IRU的致病机制有助于开发有效的CMV IRU治疗方法或预防CMV IRU的诊断或治疗策略。

DESCRIPTION (provided by applicant): Among patients with AIDS and cytomegalovirus retinitis (CMVR) who have become immunorestored by antiretroviral therapy and can discontinue anti-CMV therapy without further retinitis progression, a new cause of visual impairment has emerged-- immune recovery uveitis (IRU). The aim of this proposal is to investigate the role that aberrant T cell function may have in the immunopathogenesis of CMV IRU. We propose to test the following hypotheses, which are suggested by our preliminary data and by recent reports with animal models of autoimmune and post-infectious uveitis: 1) that an imbalance between CMV-specific CD4+ and CD8+ T cell cytokine responses and/or a deficit in regulatory CD4+ T cells (Treg) are more common in PBMC of patients with CMV IRU than in immunorestored CMVR patients who do not develop IRU and 2) that measuring such aberrant T cell responses by flow cytometry may have potential clinical utility as a screening test to identify immunorestored CMVR patients at risk for developing IRU. This proposal has a case-control design. Stored PBMC that have already been collected in an NEI-sponsored, multicenter, observational study of CMVR natural history will be thawed and assayed by flow cytometry for CMV-specific CD4+ T cell IL-2 and CD8+ T cell IFN?, TNFa and CD107a/b responses and Treg content. Assay results will be compared from case and matched controls who were all diagnosed with AIDS and CMVR and were immunorestored by antiretroviral therapy and who did (cases) or did not (controls) have IRU diagnosed during the parent longitudinal study. The effect of depleting Treg from PBMC and of adding back flow-sorted Treg cells to Treg-depleted PBMC specimens on CMV-specific, as well as anti-CD3-induced, CD8+ T cell functional responses will also be examined in order to understand the mechanism by which Treg function may impact on CMV-specific CD8+ T cell effector responses in cases and controls. In these latter experiments, anti-IL-10 and/or anti-TGF¿ antibodies will also be used to test whether regulation of CMV-specific CD8+ T cell responses depends on these cytokines. Cytomegalovirus retinitis (CMVR) remains an important complication of AIDS in the US and Europe and is emerging as an important AIDS complication internationally, especially in Asia. In the US, CMV immune recovery uveitis (IRU) now accounts for 50% of incident vision loss in AIDS patients with longstanding CMVR and antiretroviral treatment-mediated immune recovery. There is no effective therapy for CMV IRU. Thus, understanding the disease mechanism of CMV IRU could facilitate development of effective therapy for CMV IRU or diagnostic or treatment strategies to prevent CMV IRU.