The role of the transcriptional regulator Lmo4 in CD8+ T cell stemness, memory formation and antitumor immunity

转录调节因子Lmo4在CD8 T细胞干性、记忆形成和抗肿瘤免疫中的作用

• 批准号: 421981137
• 负责人: Dr. Roland Schelker
• 金额: --
• 依托单位: Klinik und Poliklinik für Innere Medizin III
• 依托单位国家: 德国
• 项目类别: Research Fellowships
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/421981137?language=en
• 关键词: role; transcriptional; regulator; Lmo4; CD8+

Similar to other organ systems, the CD8+ T cell compartment includes cells, which are at different phases of differentiation. In a primary immune response, naive T cells (TN) proceed to T memory stem cells (TSCM), central memory T cells (TCM) and effector memory T cells (TEM), culminating in the genesis of short-lived effector T cells (TEFF). Several pieces of evidence suggest that TSCM have stem cell-like features, more than any other memory T cell population. At the same time, the capability of memory T cells to induce tumor reduction progressively diminishes from TSCM to TCM and TEM. Therefore, discovering strategies that generate and expand TSCM is crucial for the development of the next generation of T cell-based immunotherapies. Various transcriptional networks are used by T cells to facilitate the generation and maintenance of TSCM and to restrict terminal effector differentiation. A potential candidate gene is the transcriptional regulator LIM domain only 4 (Lmo4), which will be the topic of the proposed project. The host laboratory has found that Lmo4 is overexpressed in culture conditions favoring the induction of TSCM. Moreover, they demonstrated that by enforcing the expression of Lmo4 in CD8+ T cells, T cell expansion and memory formation in virus-infected mice was enhanced. Based on the preliminary data, I propose to dissect the role of the transcriptional regulator Lmo4 in CD8+ T cell stemness, memory formation and antitumor immunity. First, the effect of Lmo4 on proliferation and apoptosis of transferred antigen-specific CD8+ T cells will be evaluated following infection of recipient mice with a recombinant strain of vaccinia virus encoding the cognate antigen gp100 (gp100-VV). Furthermore, the frequency of memory precursors and TEFF at peak of the acute immune response and the expression of various cytokines, which are differently expressed in the course of differentiation, will be analyzed. Moreover, the impact of Lmo4 expression on T cell metabolism will be tested and it will be explored if the generation of TSCM could be increased by amplifying Lmo4 expression. Afterwards, the plan is to elucidate downstream effectors of Lmo4 and to evaluate how the genetic manipulation of Lmo4 would affect expression of these genes in the context of CD8+ T cell differentiation. Next, I will evaluate if the enhanced generation of TSCM will promote stronger recall responses after re-challenging mice with an adenovirus encoding gp100 antigen (gp100-Adv) and will determine the efficacy of Lmo4-overexpressing cells adoptively transferred into mice bearing subcutaneous melanomas. To evaluate if the Lmo4-overexpression cohort develop long-lasting antitumor immune responses the animals will be re-challenged with tumors.

与其他器官系统类似，CD 8 + T细胞区室包括处于不同分化阶段的细胞。在初次免疫应答中，初始T细胞（TN）继续发展为T记忆干细胞（TSCM）、中枢记忆T细胞（TCM）和效应记忆T细胞（TEM），最终形成短寿命效应T细胞（TEFF）。一些证据表明，TSCM具有干细胞样特征，比任何其他记忆T细胞群体都多。同时，记忆T细胞诱导肿瘤缩小的能力从TSCM到TCM和TEM逐渐减弱。因此，发现产生和扩展TSCM的策略对于开发下一代基于T细胞的免疫疗法至关重要。T细胞使用各种转录网络来促进TSCM的产生和维持并限制末端效应物分化。一个潜在的候选基因是转录调节因子LIM结构域仅4（Lmo 4），这将是拟议项目的主题。宿主实验室发现，Lmo 4在有利于诱导TSCM的培养条件下过表达。此外，他们证明，通过加强CD 8 + T细胞中Lmo 4的表达，病毒感染小鼠的T细胞扩增和记忆形成得到增强。基于初步的数据，我建议解剖的作用，转录调节Lmo 4在CD 8 + T细胞干细胞，记忆形成和抗肿瘤免疫。首先，在用编码同源抗原gp 100（gp 100-VV）的重组牛痘病毒株感染受体小鼠后，评价Lmo 4对转移的抗原特异性CD 8 + T细胞的增殖和凋亡的影响。此外，将分析急性免疫应答峰值时记忆前体和TEFF的频率以及在分化过程中不同表达的各种细胞因子的表达。此外，将测试Lmo 4表达对T细胞代谢的影响，并将探索是否可以通过扩增Lmo 4表达来增加TSCM的产生。之后，该计划是阐明Lmo 4的下游效应子，并评估Lmo 4的遗传操作如何在CD 8 + T细胞分化的背景下影响这些基因的表达。接下来，我将评估增强的TSCM一代是否会促进更强的回忆反应后，再用腺病毒编码的gp 100抗原（gp 100-Adv）的小鼠，并将确定过继转移到小鼠皮下黑色素瘤Lmo 4过表达细胞的疗效。为了评估Lmo 4过表达组群是否产生持久的抗肿瘤免疫应答，将用肿瘤再攻击动物。