U01 Proposal Transfer - 2021

我们研究的目标是产生强大和持久的肿瘤特异性T细胞反应 化疗耐药上皮性卵巢癌(EOC)患者的持久肿瘤消退。虽然 使用免疫检查点阻断、过继T细胞疗法或溶瘤病毒的免疫疗法已经产生 在其他几种肿瘤类型中效果显著，但在卵巢癌患者中，长期肿瘤控制一直很少见。 我们小组的研究已经确定了支撑免疫疗法有限疗效的关键绊脚石 在EOC中，这包括：(I)肿瘤来源的CXCL12的产生，招募肿瘤内的T调节细胞和 抑制性髓系细胞：(II)肿瘤浸润性T淋巴细胞上多种共抑制受体的表达 (TIL)，(Iii)阻断一条途径后免疫检查点的代偿性上调，(Iv)低内在 肿瘤的免疫原性部分依赖于干扰素β产生的减少，(V)TIL无法抵抗免疫 转化生长因子β等抑制性细胞因子介导的抑制和(Vi)免疫适应性上调 抑制检查站。虽然组合免疫治疗策略有可能克服这些 固有的和获得性免疫抵抗机制，它们通常与令人无法接受的高发病率有关 对病人的毒副作用。我们的建议使用创新的、临床可翻译的、 最先进的策略，同时重新编程肿瘤微环境(TME)和T细胞，同时 将高系统性毒性的可能性降至最低。 我们之前已经证明，携带CXCR4拮抗剂的溶瘤牛痘病毒 (OV-CXCR4-Fc)可导致直接肿瘤溶解，但由于以下原因而无法预防肿瘤复发 多种免疫检查点受体上调和T细胞在TME中的持久性不足 增加免疫抑制的TGFb水平。为了克服这些限制，我们建议测试一下疗效 一种含有CXCR4拮抗剂和多个检查点抑制剂的多方面溶瘤病毒， 然后过继转移肿瘤抗原特异性T细胞，以抵抗转化生长因子β。我们假设 多能溶瘤病毒对体内肿瘤的破坏将限制免疫反应的抑制 TME，从而进一步促进转移的T细胞的侵袭和持续的抗肿瘤功能 经设计可抵抗转化生长因子β。为了验证这一假设，我们提出了三个具体目标： 目的1.筛选溶瘤痘苗病毒载体免疫检查点抑制剂的最佳组合 这将有效地增强OV-CXCR4-FC的疗效。 目的2.确定OV-CXCR4-Fc-MICB与过继转移的T细胞的治疗协同作用。 对转化生长因子β不敏感。 目的3.制备和鉴定重组溶瘤剂的主病毒库(MVB)和最终产物(FP 在AIMS 1和AIMS 2中选择的痘苗病毒，用于IND资格。

The goal of our studies is to generate robust and long-lasting tumor-specific T cell responses for durable tumor regression in patients with chemotherapy-resistant epithelial ovarian cancer (EOC). Although immunotherapy using immune checkpoint blockade, adoptive T cell therapy, or oncolytic viruses has generated remarkable results in several other tumor types, long-term tumor control has been infrequent in EOC patients. Studies by our group have identified key stumbling blocks underpinning the limited efficacy of immunotherapy in EOC, which include: (i) tumor-derived CXCL12 production that recruits intra-tumoral T regulatory cells and suppressive myeloid cells, (ii) expression of multiple co-inhibitory receptors on tumor infiltrating T lymphocytes (TIL), (iii) compensatory upregulation of immune checkpoints upon blockade of one pathway, (iv) low intrinsic tumor immunogenicity partially dependent on reduced IFNβ production, (v) inability of TIL to resist immune suppression mediated by inhibitory cytokines such as TGFβ, and (vi) adaptive upregulation of immune inhibitory checkpoints. While combinatorial immunotherapy strategies have the potential to overcome these intrinsic and adaptive immune resistance mechanisms, they are often associated with unacceptably high rates of toxicities in patients. Our proposal addresses these stumbling blocks using innovative, clinically translatable, state-of-the-art strategies to concomitantly reprogram the tumor microenvironment (TME) and T cells, while minimizing the potential for high rates of systemic toxicities. We have previously demonstrated that an oncolytic vaccinia virus armed with a CXCR4 antagonist (OV-CXCR4-Fc) results in direct tumor oncolysis but is incapable of preventing tumor recurrence due to upregulation of multiple immune checkpoint receptors and insufficient persistence of T cells in the TME due to increasing levels of immunosuppressive TGFb. To overcome these limitations, we propose to test the efficacy of a multifaceted oncolytic virus incorporating the CXCR4 antagonist and multiple checkpoint inhibitors, followed by adoptive transfer of tumor antigen-specific T cells engineered to resist TGFβ. We hypothesize that in vivo tumor destruction by the multipotent oncolytic virus will limit dampening of the immune response in the TME and thus further promote the infiltration and sustained anti-tumor function of the transferred T cells engineered to resist TGFβ. To test this hypothesis, we propose three specific aims: Aim 1. To select the optimal combination of oncolytic vaccinia virus-delivered immune checkpoint inhibitors that would effectively augment the efficacy of OV-CXCR4-Fc. Aim 2. Determine the therapeutic synergy of OV-CXCR4-Fc-MICB with adoptively transferred T cells that are rendered insensitive to TGFβ. Aim 3. To manufacture and certify a Master Viral Bank (MVB) and Final Product (FP) of recombinant oncolytic vaccinia virus selected in Aims 1 and 2 for IND qualification.