Defining a novel role for B cells in imprinting CD8 T cells with potent antitumor activity

项目摘要 使用肿瘤浸润性T淋巴细胞(TIL)的过继细胞转移(ACT)治疗癌症患者 未能充分发挥其潜力，主要是由于耗尽的、短暂的CD8+T细胞的转移。最近，我们 发现在含有Toll样受体9的TIL培养中，通过激活B细胞可以改善T细胞的适应性 (TLR)激动剂CpG。理解和操纵维持T细胞持久性的TLR通路将 潜在地解锁了对肿瘤的持久反应。此外，关于B和CD8+T细胞如何相互作用的研究很少 促进T细胞肿瘤免疫。在这项建议中，我们试图阐明T细胞 从CpG处理的培养中产生，能够在体内消除已建立的肿瘤，而不需要IL-2或 疫苗接种。我们的初步数据显示，经CpG处理的B细胞有明显的CD40(共刺激 蛋白)，同时CD8+T细胞表达CD40L。我们发现，在这个时候，CD8+T细胞获得了T 以CXCR5、ICOS和PD-1表达为标志的滤泡记忆样(TFML)表型。我们假设CD40 CpG处理后B细胞中的信号转导与CD8+TFML细胞的发育有关 抗肿瘤活性。经CpG处理后产生的CD8+T细胞获得一种独特的表型，表示为高 IL-2细胞因子受体IL-2R？和CD39的微弱表达？我的合作导师马克·鲁宾斯坦博士 最近发表的IL-2R的重要性？在ACT模型中促进T细胞的植入。 相反，CD39只在CpG产生的T细胞上最低限度地表达，与赋形剂处理的T细胞相比 细胞，是与病毒和癌症模型中“终末耗尽”的CD8+T细胞相关的标志。因此，我寻求 研究CpG如何诱导这种强大的细胞产物的机制以及IL-2R的作用？和CD39 在获得强大的抗肿瘤反应方面。总体而言，我假设TLR9激动剂CpG能激活B细胞。 抗肿瘤T细胞培养，通过CD40信号在B细胞中促进T细胞印迹TFML表型。我 我将在目标1中检验这一想法。此外，我假设IL-2R？和CD39，受TLR9信号反向调节， 负责增强过继转移的CD8+T细胞的抗肿瘤特性。这一概念将 将在目标2中进行分析。揭示CpG如何激活B细胞成为有效的抗原提呈物 AIM 1中细胞向CD8+T细胞转化将为Toll样受体激动剂治疗癌症建立新的范例 中央警卫队。此外，这些研究的发现将为了解具有很强免疫力的T细胞的产生提供洞察力 对肿瘤的记忆，将对癌症患者具有重要的临床意义。整体而言，建议的 研究有望证明，通过CpG激活TLR9通路可能足以诱导 对晚期肿瘤的生长和复发具有持久的免疫力。

Project Summary Adoptive cell transfer (ACT) therapies using tumor infiltrating T lymphocytes (TIL) for cancer patients have failed to fulfill their full potential, mostly due to the transfer of exhausted, short-lived CD8+ T cells. Recently, we discovered that T cell fitness can be improved by activating B cells in a TIL culture with the Toll-like receptor 9 (TLR) agonist CpG. Understanding and manipulating the TLR pathways that sustain T cell persistence will potentially unlock durable responses to tumors. Further, there is little research on how B and CD8+ T cells interact to promote T cell tumor immunity. In this proposal we seek to elucidate the mechanism by which T cells generated from a CpG-treated culture, are able to abolish established tumors in vivo without the need of IL-2 or vaccine administration. Our preliminary data shows B cells treated with CpG have overt CD40 (costimulatory protein) and concomitantly CD8+ T cells express CD40L. We found that at this time CD8+ T cells acquire a T follicular memory-like (TFML) phenotype denoted by CXCR5, ICOS, and PD-1 expression. We posit that CD40 signaling in B cells post CpG-treatment is responsible for the development of CD8+ TFML cells and potentiated antitumor activity. CD8+ T cells generated from CpG-treated cultures gain a unique phenotype denoted by high expression of the IL-2 cytokine receptor IL-2R? and dim expression of CD39? My co-mentor Dr. Mark Rubinstein recently published the importance of the IL-2R? in promoting engraftment of T cells in an ACT model. Conversely, CD39 which is only minimally expressed on CpG-generated T cells compared to vehicle treated T cells, is a marker associated with “terminally exhausted” CD8+ T cells in viral and cancer models. Thus, I seek to study the mechanisms underlying how CpG induces this potent cell product and the roles of IL-2R? and CD39 in achieving robust antitumor responses. Overall, I hypothesize that TLR9 agonist CpG activates B cells in an antitumor T cell culture, promoting T cells to be imprinted with a TFML phenotype via CD40 signaling in B cells. I will examine this idea in Aim 1. Moreover, I posit that IL-2R? and CD39, inversely regulated by TLR9 signaling, are responsible for augmenting the antitumor properties of adoptively transferred CD8+ T cells. This concept will be analyzed in Aim 2. Uncovering how B cells can be activated by CpG to become potent antigen presenting cells to CD8+ T cells in Aim 1 will establish a new paradigm for cancer therapy with Toll-like receptor agonist CpG. Also, findings from these studies will provide insight into the generation of T cells with strong immunological memory to tumors and will have important clinical implications for patients with cancer. Overall, the proposed research is expected to demonstrate that activation of the TLR9 pathway with CpG may sufficiently induce durable immunity against the growth and recurrence of advanced tumors.