Enhancing CD8 T Cell Function by Abrogating Inhibition by Regulatory Proteins

描述（由申请人提供）：大量体外扩增抗原特异性CDS T细胞的过继免疫治疗有可能成为癌症或病毒感染的一种新的安全治疗方式，但疗效通常有限。一个障碍是供体T细胞在体内的存活和功能保留不足，这通常可以通过CD4辅助T细胞的共转移或通过IL-2替代CD4辅助T细胞来维持。然而，许多肿瘤尚未发现特异性辅助性CD4 T细胞，CD4 T细胞通常是限制性的，并且在治疗HIV感染期间可能会造成额外的问题，并且长时间的高剂量IL-2补充可能既低效又有毒。过继性免疫治疗的另一个主要障碍可能是转移的T细胞在体内不能被病毒和肿瘤靶点有效激活。肿瘤特异性T细胞通常具有低亲和力的tcr，恶性或感染的靶标可具有受损的抗原加工机制或辅助信号，并且对靶标细胞的长时间识别可诱导T细胞耐受。因此，增加CDS T细胞产生IL-2和自分泌IL-2介导的增殖能力，降低CDS T细胞活化的阈值，或防止抗原特异性CDS T细胞耐受的诱导，应显著提高过继免疫治疗策略的疗效。增加CDS T细胞活性和功能或维持自分泌IL-2增殖和存活的一种潜在手段是减少由细胞内调节蛋白介导的转移CDS T细胞中的抑制信号。我们已经确定了cl -b、SHP-1和SOCS-1作为增强CDS T细胞活力和功能的潜在靶点。缺乏这些基因的小鼠的CDS T细胞导致T细胞反应性和共刺激独立的IL-2产生增加。该项目的主要目标是确定通过表达显性阴性版本的ccl -b、SHP-1或SOCS-1来降低CDS T细胞中激活信号的负调控，或通过表达特定siRNA来降低内源性这些蛋白质的水平，是否可以改善T细胞的活性和功能，并使这些细胞在小鼠模型中更有效地治疗慢性病毒感染或恶性肿瘤。此外，我们将在临床前研究中确定取消这些调节蛋白的抑制是否可以增强人类CDS T细胞的贪婪性、增殖和存活。

DESCRIPTION (provided by applicant): Adoptive immunotherapy with large numbers of in vitro expanded antigen-specific CDS T cells has the potential to become a novel and safe treatment modality for cancer or viral infections, but efficacy is often limited. One obstacle is insufficient in vivo survival and retention of function by donor T cells, which can often be sustained by cotransfer of CD4 helper T cells or by IL-2 administration to substitute for CD4 help. However, specific helper CD4 T cells have not been identified for many tumors, CD4 T cells are often limiting and can be pose additional problems during treatment of HIV infection, and prolonged high-dose IL-2 supplementation can be both inefficient and toxic. Another major obstacle to adoptive immunotherapy can be the failure of transferred T cells to be effectively activated by viral and tumor targets in vivo. T cells specific for tumors often have low affinity TCRs, malignant or infected targets can have impaired antigen processing machinery or accessory signals, and prolonged recognition of target cells can induce T cell tolerance. Thus, increasing the capacity of CDS T cells for IL-2 production and autocrine IL-2 mediated proliferation, reducing the threshold for CDS T cell activation, or preventing induction of tolerance in antigen-specific CDS T cells should significantly enhance the efficacy of adoptive immunotherapeutic strategies. One potential means to increase CDS T cell avidity and function or sustain autocrine IL-2 proliferation and survival is to reduce inhibitory signals in transferred CDS T cells mediated by intracellular regulatory proteins. We have identified Cbl-b, SHP-1, and SOCS-1 as potential targets to enhance CDS T cell aviditiy and function. CDS T cells from mice deficient in these genes results in increased T cell reactivity and costimulation independent IL-2 production. The major goals of this project are to determine if decreasing the negative regulation of activation signals in CDS T cells by Cbl-b, SHP-1, or SOCS-1 by expression of dominant negative versions of these proteins, or by reducing endogenous levels of these proteins via expression of specific siRNA, can improve T cell avidity and function and render these cells more effective in therapy of chronic viral infections or malignancy in mouse models. Additionally, we will determine if abrogating inhibition by these regulatory proteins can enhance the avidity, proliferation and survival of human CDS T cells in preclinical studies. Chronic viral infections and cancer represent major public health concerns. Adoptive immunotherapy with T cells has the potential to become an effective and broadly applicable approach for the treatment of viral infections and malignancy. However, the efficacy of transferred T cells is limited by insufficient in vivo survival and function. These studies will determine if genetically modifying T cells to improve function and survival can enhance adoptive immunotherapy approaches in mouse models of chronic viral infection or malignancy as well as the survival and function of human virus and tumor specific T cells in preclinical studies.