Enhancing HIV-specific CTL by CD27/CD70 costimulation

通过 CD27/CD70 共刺激增强 HIV 特异性 CTL

• 批准号: 7140587
• 负责人: Premlata Shankar
• 金额: $ 27.68万
• 依托单位: IMMUNE DISEASE INSTITUTE, INC.
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-06-01 至 2008-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7140587
• 关键词: CD antigens; RNA interference; SDS polyacrylamide gel electrophoresis; affinity chromatography; antigen presenting cell; blocking antibody; blood chemistry; cell growth regulation; clinical research; cytotoxic T lymphocyte; flow cytometry; green fluorescent proteins; human immunodeficiency virus 1; human subject; interferon gamma; leukocyte activation /transformation; western blottings

DESCRIPTION (provided by applicant): Although HIV infected individuals generate a large number of antigen-specific CD8 T cells, they are unable to control the virus and eventually develop clinical AIDS. We, and others have shown that freshly isolated HIV-specific CD8 T cells are functionally impaired. Further preliminary results suggest that HIV-specific T cells but not CMV-specific T cells from the same infected individual exhibit phenotypic features of immaturity. One striking phenotypic difference between HIV-specific CD8 T cells from CD8 T cells responding to other well-controlled chronic viruses such as CMV, is the failure to downmodulate the TNF family costimulatory molecule CD27. CD27 downmodulation normally occurs after interaction with its ligand CD70, and this interaction appears to be critical for the terminal maturation of T cells and expression of the key cytotoxic molecule perforin. Thus, the underlying defect in HIV infection may be a failure to express CD70, resulting in the failure to generate CD27 triggered costimulatory signals. To test this hypothesis, in Aim 1, we will investigate whether providing CD70 exogenously restores or enhances proliferation, cytotoxicity and IFN-gamma secretion of HIV-specific CD8 T cells. As EBV-transformed B lymphoblastoid cell lines (BLCLs) express CD70 abundantly, we will first test if blockade/abrogation of the molecule on autologous BLCLs diminishes their ability to stimulate HIV-specific CTL. We will also provide CD70 exogenously in soluble form or by lentiviral delivery during ex vivo culture of the cells with and without antigen stimulation, and test their ability to kill HIV-infected and peptide-pulsed targets and to produce cytokines. Because a small subpopulation of HIV-infected individuals, the long-term nonprogressors are able to control the virus in the absence of treatment, in the second specific aim, we will examine whether an intact CD70 costimulation pathway is responsible for maintenance of a functional virus-specific CD8 T cells in these subjects. We will block CD27/CD70 interactions during ex vivo stimulation using blocking antibody, CD27Ig chimera and RNAi and test if this treatment diminishes their responsiveness.

描述（由申请人提供）：尽管艾滋病毒感染的个体会产生大量抗原特异性CD8 T细胞，但他们无法控制该病毒并最终发展临床辅助物。我们和其他人已经表明，新鲜分离的HIV特异性CD8 T细胞在功能上受损。进一步的初步结果表明，来自相同感染的个体的HIV特异性T细胞而不是CMV特异性T细胞表现出不成熟的表型特征。来自CD8 T细胞的HIV特异性CD8 T细胞之间的一个显着的表型差异，这些CD8 T细胞响应其他良好控制的慢性病毒，例如CMV，是未能下调TNF家族共刺激分子CD27。 CD27下调通常发生在与配体CD70相互作用后，这种相互作用对于T细胞的终末成熟和关键细胞毒性分子穿孔的表达至关重要。因此，艾滋病毒感染中的潜在缺陷可能是无法表达CD70，导致未能产生CD27触发的共刺激信号。为了检验这一假设，在AIM 1中，我们将研究CD70外源恢复或增强HIV特异性CD8 T细胞的增殖，细胞毒性和IFN-GAMMA分泌。当EBV转换的B淋巴细胞细胞系（BLCLS）表达CD70时，我们将首先测试分子在自体BLCL上的封锁/废除会降低其刺激HIV特异性CTL的能力。我们还将在具有和没有抗原刺激的细胞的离体培养过程中以可溶性形式或慢病毒递送外源性CD70，并测试其杀死感染HIV感染和肽脉冲靶标并产生细胞因子的能力。 由于对感染HIV的个体的小亚群，因此长期的非促进者能够在没有治疗的情况下控制病毒，在第二个特定目的中，我们将检查完整的CD70 costimuntion途径是否负责维持这些受试者中功能性病毒特异性CD8 T细胞。我们将使用阻断抗体，CD27ig Chimera和RNAi在离体刺激过程中阻止CD27/CD70相互作用，并测试这种处理是否会降低它们的响应性。