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高度组织化的结构，类似于 淋巴结，称为三级淋巴结构（TLS），这是与更好的 许多肿瘤的结果。TFH细胞对于生发中心的形成至关重要， 体液反应，我们的新数据表明，TFH细胞成为主要的生产者， CXCL 13和TNFS 14/LIGHT。TLS的组装和维护应 因此，这取决于TFH的反应。我们的新数据表明， 序列结合蛋白-1（Satb 1）在T细胞中特异性消融导致TFH增强 分化和增强的Ag特异性体液反应，这与 同时进行ICOS和PD-1去阻遏。因此，我们的中心假设是， LIGHT+ CXCL 13 + TFH细胞的形成以及随后TLS在癌症中的协调， CD 4 T细胞中Satb 1沉默通过TFH细胞中的ICOS去抑制和 通过PD-1抑制Foxp 3 +PD-1highCXCR 5 + T滤泡调节（TFR）细胞形成 上调因此，TGF-β矛盾地增强了TFH细胞的生成， 通过Satb 1抑制形成TLS。 在目标1中，我们将定义在TFH过程中SATB 1依赖性ICOS表达的作用。 分化通过ChIP-PCR和Satb 1-competent vs. Satb 1- 在体内缺乏T细胞，我们将证实一种新的表观遗传机制， 基因组组织者Satb 1控制ICOS表达，导致TFH分化增强， 没有satb 1。 在目标2中，我们将确定SATB 1在TGF-β驱动的、Treg依赖的TFH中的作用。 分化在这里，我们将结合联合收割机基因操作和现有的转基因模型， 确定TGF-β驱动TFH分化的机制在多大程度上是Satb 1-和PD-1-。 依赖性，以需要减少TFR形成的方式。 在目标3中，我们将概括导致形成和保护活性的机制。 TLS在卵巢癌中的应用通过利用独特的转基因模型，我们的卵巢癌- 特异性CAR T细胞和我们的来自新鲜分离的卵巢癌细胞的活单细胞悬浮液 我们将定义一个新的TGF-β → Satb 1沉默→ TFH细胞形成轴驱动的肿瘤， 相关的抗肿瘤体液应答。 我们的工作将通过阐明表观遗传程序是如何 由SATB 1控制，以TGF-β依赖的方式控制肿瘤床处TFH细胞的产生。 方式在体内重述这些机制将为更有效的 免疫疗法旨在通过免疫抑制剂促进体液和T细胞联合应答。 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.