B cell-dependent anti-tumor immunity in ovarian cancer

摘要 在肿瘤床内，T和B细胞经常相互作用，形成类似于 淋巴结，称为三级淋巴结构(TLS)，与更好的 在许多肿瘤中的结果。TFH细胞对生发中心的形成和 体液反应，我们的新数据表明，TFH细胞成为主要的产生 CXCL13和TNFS14/LIGH。TLS的组装和维护应 因此，要依赖TFH的反应。我们的新数据表明，特殊的AT-Rich 在T细胞中特异性地去除序列结合蛋白-1(Satb1)导致TFH增强 分化和增强的Ag特异性体液反应，这与 同时抑制ICOS和PD-1的表达。因此，我们的中心假设是 轻CXCL13 TFH细胞的形成，以及随后TLS在癌症中的编排，是 通过抑制TFH细胞和TFH细胞中ICOS抑制CD4T细胞中的Satb1沉默 通过PD-1抑制Foxp3 PD-1HighCXCR5 T滤泡调节细胞的形成 上调监管。因此，转化生长因子-β矛盾地促进了TFH细胞的生成和 通过Satb1抑制形成TLS。 在目标1中，我们将确定SATB1依赖的ICOS表达在TFH中的作用 差异化。通过芯片聚合酶链式反应和功能分析，比较了Satb1与Satb1的同源性。 在体内缺乏T细胞，我们将证实一种新的表观遗传机制，即大师 基因组组织者Satb1调控ICOS表达，导致TFH分化增强 Satb1的缺席。 在目标2中，我们将确定SATb1在转化生长因子β驱动的、Treg依赖的TFH中的作用 差异化。在这里，我们将结合地质操纵和现有的转基因模型来 确定转化生长因子-β诱导的促甲状腺激素分化机制在多大程度上是sATB-1和PD-1- 依赖，以一种需要减少TFR形成的方式。 在目标3中，我们将概述导致形成和保护活性的机制 TLS在卵巢癌体内的表达。通过利用独特的转基因模型，我们的卵巢癌- 从新鲜分离的卵巢中提取的特异性CAR T细胞和我们的活性单细胞悬液 癌症，我们将定义一个新的转化生长因子-β→-Satb1沉默→细胞形成轴驱动 相关的抗肿瘤体液反应。 我们的工作将通过阐明表观遗传程序如何在该领域产生深远的影响 SATb1调控转化生长因子-β依赖性肿瘤细胞在肿瘤床上的生成 举止。在体内重述这些机制将为更有效地 免疫疗法旨在促进体液和T细胞的联合反应，通过 TLS在不可切除/转移性肿瘤中的协调，并可能导致识别 在肿瘤床上自发产生的具有抗肿瘤活性的抗体。

ABSTRACT Within tumor beds, T and B cells often interact to form highly organized structures similar to lymph nodes, termed tertiary lymphoid structures (TLS), which are associated with better outcomes in many tumors. TFH cells are crucial for the formation of germinal centers and humoral responses, and our new data show that TFH cells become the main producers of CXCL13 and TNFS14/LIGHT upon vaccination. The assembly and maintenance of TLS should be therefore dependent on TFH responses. Our new data demonstrate that Special AT-rich sequence-binding protein-1 (Satb1) ablation specifically in T cells leads to enhanced TFH differentiation and augmented Ag-specific humoral responses, which is associated with concurrent ICOS and PD-1 de-repression. Accordingly, our central hypothesis is that LIGHT+CXCL13+ TFH cell formation and, subsequently, the orchestration of TLS in cancer, is governed by Satb1 silencing in CD4 T cells by both de-repressing ICOS in TFH cells and suppressing Foxp3+PD-1highCXCR5+ T follicular regulatory (TFR) cell formation through PD-1 up-regulation. Therefore, TGF-β paradoxically enhances the generation of TFH cells and the formation of TLS through Satb1 repression. In Aim 1, we will define the role of SATB1-dependent ICOS expression during TFH differentiation. Through ChIP-PCR and functional analysis of Satb1-competent vs. Satb1- deficient T cells in vivo, we will substantiate a novel epigenetic mechanism whereby the master genomic organizer Satb1 governs ICOS expression, leading to enhanced TFH differentiation in the absence of Satb1. In Aim 2, we will determine the role of SATB1 in TGF-β-driven, Treg-dependent TFH differentiation. Here, we will combine geentic manipulation and existing transgenic models to establish to what extent the mechanism of TGF-β-driven TFH differentiation is Satb1- and PD-1- dependent, in a manner that requires decreased TFR formation. In Aim 3, we will recapitulate the mechanisms leading to the formation and protective activity of TLS in vivo in ovarian cancer. By leveraging unique transgenic models, our ovarian cancer- specific CAR T cells and our viable single-cell suspensions from freshly dissociated ovarian carcinomas, we will define a novel TGF-β → Satb1 silencing → TFH cell formation axis driving relevant anti-tumor humoral responses. Our work will exert a profound effect in the field by elucidating how epigenetic programs controlled by SATB1 govern the generation of TFH cells at tumor beds in a TGF-β-dependent manner. Recapitulating these mechanisms in vivo will pave the way for more effective immunotherapies aimed to promote combined humoral and T cell responses through the orchestration of TLS in irresectable/metastatic tumors, and could lead to the identification of antibodies with anti-tumor activity spontaneously produced at tumor beds.