Remotely controlled listerial bactodrones for cancer immunotherapy

项目摘要 通过静脉注射递送的减毒和无毒的单核细胞增生李斯特菌（Lm）菌株， 在原发性肿瘤和转移瘤中积累和传播，同时从健康组织中快速清除。 我们打算将这些菌株用作远程控制的肿瘤特异性抗癌有效载荷运载工具， bactodrones。在这个项目中，我们将工程Lm合成和分泌环状二核苷酸（c-di-NMPs）， 肿瘤微环境内的强效先天免疫系统刺激物。c-di-NMP的原位蓄积 将通过STING先天免疫途径诱导I型干扰素的产生。这将改善 Lm诱导免疫原性肿瘤细胞死亡并导致肿瘤相关抗原释放的能力， 这将促进肿瘤特异性CD 8 T细胞的募集。持续的肿瘤局部c-di-NMP 生产将保持T细胞和其他抗癌免疫细胞激活。评估的可行性和有效性 通过基因工程Lm递送肿瘤内c-di-NMP，我们将追求两个目标。在目标1中， 工程化Lm以分泌用于在免疫和肿瘤细胞中合成c-di-NMP的酶。在aim 2中， Lm将通过称为细菌转染的过程递送编码c-di-NMP酶的质粒。两 这些方法有望将肿瘤微环境中的感染细胞转化为产生c-di-NMP的细胞， 工厂并确保持久的STING激活。重要的是，Lm介导的c-di-NMP递送系统将是 用良性化学诱导剂进行诱导，这将能够暂时控制STING激活， 限制与全身c-di-NMP暴露相关的毒性。在Lm bactodrones的优化之后， 在体外和乳腺癌细胞系中，我们将测试周期性bactodrone注射在小鼠转移瘤中的功效。 乳腺癌模型。我们预计Lm bactodrones将成为肿瘤定位的有效载体， 用于各种抗肿瘤活性的遗传有效载荷的时间受控和廉价的递送。

PROJECT SUMMARY Attenuated and avirulent strains of Listeria monocytogenes (Lm), that are delivered via intravenous injections, accumulate and propagate in primary tumors and metastases while being quickly cleared from healthy tissues. We intend to use these strains as remotely controlled, tumor-specific anticancer payload delivery vehicles, bactodrones. In this project we will engineer Lm to synthesize and secrete cyclic dinucleotides (c-di-NMPs) as potent innate immune system stimulators inside tumor microenvironments. On-site accumulation of c-di-NMPs will induce production of type I interferon via the STING innate immunity pathway. This will improve the capacity of Lm to induce immunogenic tumor cell death and lead to the release of tumor-associated antigens, which will facilitate recruitment of tumor-specific CD8 T cells. The sustained tumor-localized c-di-NMP production will keep T cells and other anticancer immune cells activated. To assess feasibility and efficacy of delivering intratumoral c-di-NMP via genetically engineered Lm, we will pursue two aims. In aim 1, we will engineer Lm to secrete enzymes for c-di-NMP synthesis in immune and tumor cells. In aim 2, the engineered Lm will deliver plasmids encoding a c-di-NMP synthases, via a process known as bactofection. Both approaches are expected to turn infected cells in the tumor microenvironment into c-di-NMP producing factories and ensure durable STING activation. Importantly, Lm-mediated c-di-NMP delivery systems will be made inducible with a benign chemical inducer, which will enable temporal control of STING activation and limit toxicity associated with systemic c-di-NMP exposure. Following optimization of the Lm bactodrones in vitro, and in breast cancer cell line, we will test efficacy of periodic bactodrone injections in a mouse metastatic breast cancer model. We anticipate that Lm bactodrones will become efficient vehicles for tumor-localized, temporally controlled and inexpensive delivery of genetic payloads for various antitumor activities.