Vaccine Targeting of RCC Blood Vessels to Promote TME Normalization and Enhance TIL Recruitment

摘要 尽管肾细胞癌通常被归类为免疫原性肿瘤，但最近的侧写研究表明 CD8TIL在这种类型的癌症中的存在是预后不良的指标。这些发现强调了 在肿瘤微环境中评价免疫环境/免疫细胞网络的重要性 解释肿瘤免疫的运行状态及其对疾病进展和应答的可能影响 到介入性治疗。事实上，如果人们转而考虑CD8T细胞和成熟DC的有组织的集群- 树突状细胞(DC)在肿瘤的三级淋巴结构(TLS)内，这些淋巴“器官”是 肾癌患者总存活率/PFS的阳性预后指标。与肿瘤相关的TLS已经被 建议作为免疫“绿洲”，为表现出较少耗尽表型的淋巴细胞渗透，以及 作为原位DC介导的不同治疗性CD8 T细胞库的交叉启动的位点。我们有 最近研究表明，接种肿瘤相关血管抗原(TBVA)可导致血管 正常化(VN；即血管修剪，减少血管渗漏/缺氧/间质液体压)和De 以介入性疫苗为基础的肿瘤内TLS在小鼠和人体内的新发展 免疫疗法。值得注意的是，我们还观察到这些疫苗的抗肿瘤效果。 深刻的性别/性二态，女性(或被阉割的男性)对完整男性的反应率更高， 这表明性激素及其受体具有调节作用。我们的中心假设是：i.) 联合免疫治疗促进肾癌VN将促进TLS的发展和AFP的产生 广泛反应的治疗性CD8 T细胞谱系，表现出卓越的“适合性”和抗肿瘤效果，以及ii。) 联合应用雄激素合成/AR可避免疫苗接种引起的性别二态反应 对抗者。考虑到慢性肾细胞癌的男性和女性发病率为2：1，这些后一项研究预计将显著 扩大以TBVA为靶点的肾癌疫苗的治疗作用。我们将首先进行一次探索性 以口服低剂量α为靶点的自体TBVADc1/多肽疫苗的临床试验 卡波赞替尼对新近确诊的原发肿瘤患者VN、TLS形成和肿瘤浸润性T细胞适合性的影响 CcRCC在计划手术切除(目标1)之前，然后进行动物模型以验证假说 这是我。)在小鼠肾细胞癌(RencA，RENCA.VHL-/-)肿瘤中能够促进VN的药物将与 针对RCC和/或TBVA抗原的疫苗/-检查点封锁促进TLS的发展， 改善肿瘤浸润性T细胞(TIL)的适合性，扩大TIL谱系和卓越的治疗效益(AIM 2)和ii.)能够阻断雄激素合成/雄激素受体信号转导的药物将得到改善 VN诱导免疫疗法对BALB/c雄性/雌性小鼠肾细胞癌的治疗效果(目标3)。

ABSTRACT Although RCC is typically classified as an immunogenic tumor, recent profiling studies instead suggest that presence of CD8+ TIL in this form of cancer is an indicator of poor prognosis. These findings emphasize the importance of appreciating immune context/immune cell networking in the tumor microenvironment when interpreting the operational status of tumor immunity and its likely impact on disease progression and response to interventional therapy. Indeed, if one instead considers organized clusters of CD8+ T cells and mature DC- LAMP+ dendritic cells (DC) within tertiary lymphoid structures (TLS) in tumors, these lymphoid “organs” are positive prognostic indicators for overall survival/PFS in RCC patients. Tumor-associated TLS have been suggested to serve as an immune “oasis” for infiltrating lymphocytes exhibiting less-exhausted phenotypes, and as sites for in situ DC-mediated cross-priming of a diversified therapeutic CD8+ T cell repertoire. We have recently shown that vaccination against tumor-associated blood vessel antigens (TBVA) results in vascular normalization (VN; i.e. vascular trimming, reduced vascular leak/hypoxia/interstitial fluid pressure) and the de novo development of TLS within tumors in mice and humans responding to interventional vaccine-based immunotherapy. Remarkably, we have also observed that the anti-tumor efficacy of these vaccines exhibits profound gender/sexual dimorphism, with higher response rates in females (or castrated males) vs. intact males, suggesting a regulatory role for sex steroids and their receptors. Our central hypotheses are that: i.) combination immunotherapy promoting VN in RCC will enhance TLS development and the generation of a broadly-reactive therapeutic CD8+ T cell repertoire exhibiting superior “fitness” and anti-tumor efficacy, and ii.) gender dimorphic response to vaccination can be circumvented by co-administration of androgen synthesis/AR antagonists. Given a 2:1 male:female incidence of ccRCC, these latter studies are expected to dramatically expand the therapeutic utility of TBVA-targeted vaccines against RCC. We will initially perform an exploratory clinical trial to determine the impact of an autologous αDC1/peptide vaccine targeting TBVA + oral low-dose cabozantinib on VN, TLS formation and tumor-infiltrating T cell fitness in patients with recently-diagnosed primary ccRCC prior to planned surgical resection (Aim 1), before then pursuing animal models to test the hypotheses that i.) agents capable of promoting VN in murine RCC (RENCA, RENCA.VHL-/-) tumors will synergize with vaccines targeting RCC and/or TBVA antigens +/- checkpoint blockade in promoting the development of TLS, improved tumor-infiltrating T cell (TIL) fitness, an expanded TIL repertoire and superior therapeutic benefit (Aim 2) and ii.) agents capable of interrupting androgen synthesis/androgen receptor-signaling will improve therapeutic efficacy of VN-inducing immunotherapies in male/female BALB/c mice bearing RCC tumors (Aim 3).