EpoxySEAKER and onSEAKER: CAR T-Cell Systems for Targeted Local Biosynthesis of Therapeutic Warheads

Epoxyseaker和Onseaker：用于靶向细胞生物合成的CAR T细胞系统 治疗弹头 我们的实验室已经开发出新型SEAKER（合成酶武装杀手）CAR T细胞， 其从全身给药的无毒前药中裂解掩蔽基团。SEAKER的本地化 细胞转化为肿瘤允许前药在目的部位特异性转化为抗癌剂。这些 SEAKER细胞克服了CAR T细胞疗法的局限性，如T细胞耗竭、免疫抑制和免疫抑制。 通过T细胞增殖、酶的组成性分泌产生级联效应， 和催化生成活性药物。这些酶继续在肿瘤处产生细胞毒性化合物 即使在T细胞功能耗尽后，也能在该部位发挥作用。我们将设计这个系统， “epoxySEAKER”和“onSEAKER”细胞，其表达细菌生物合成酶并转化非生物合成酶。 通过酶介导的治疗弹头将毒性前药底物转化为细胞毒性化合物 安装.通过消除对掩蔽部分的需要来限制前药的庞大性，我们预期更大的 前药的药理学性质。将弹头部分安装到前药上而不是裂解 掩蔽基团将消除细胞毒性剂的非特异性活化， 与目标化合物相关的毒性。 我们计划使用我们的两种新型SEAKER系统来靶向肿瘤环境，引发免疫反应， 并随后分泌EpnF或TsnB 9，其将酶促激活FDA批准的 毒品在现场我们将为两个SEAKER系统生成多种前药，并评估其转化为 活性化合物使用重组酶在体外。化合物如卡非佐米和帕比司他 当施用用于治疗多发性骨髓瘤时，与靶向非部位毒性相关。肿瘤 靶向“epoxySEAKER”或“onSEAKER”细胞将使合成酶的分泌定位于细胞内。 肿瘤部位，允许全身施用无毒前药，随后原位化合物 合成和降低的非现场毒性所证明的目标化合物。添加剂治疗 CAR-T细胞和小分子的作用将增加治疗的有效性，并可能扩大 CAR-T细胞疗法的靶向范围。

EPOXYSEAKER AND ONSEAKER: CAR T-CELL SYSTEMS FOR TARGETED LOCAL BIOSYNTHESIS OF THERAPEUTIC WARHEADS Our labs have developed novel SEAKER (Synthetic Enzyme-Armed KillER) CAR T-cells that express enzymes that cleave masking groups from systemically administered non-toxic prodrugs. The localization of SEAKER cells to tumors allows for specific conversion of the prodrug to anticancer agent at the site of interest. These SEAKER cells overcome limitations of CAR T-cell therapy such as T-cell exhaustion, immunosuppression and antigen variance by creating a cascade effect through proliferation of T-cells, constitutive secretion of enzymes and catalytic generation of the active drugs. The enzymes continue to produce cytotoxic compounds at the tumor site even after the T-cells functionally exhaust. We will engineer this system to produce novel “epoxySEAKER” and “onSEAKER” cells that express bacterial biosynthetic enzymes and convert non- toxic prodrug substrates into cytotoxic compounds through an enzyme-mediated therapeutic warhead installation. Limiting the bulkiness of the prodrug by eliminating the need for masking moieties we expect greater pharmacological properties of the prodrugs. Installing the warhead moiety onto the prodrug rather than cleaving a masking group will eliminate the non-specific activation of cytotoxic agents and reduce the on-target, off-site toxicity associated with the target compounds. We plan to use our two novel SEAKER systems to target the tumor environment, elicit immunologic responses, and subsequently secrete EpnF or TsnB9 which will enzymatically activate prodrug variants of FDA approved drugs in situ. We will generate multiple prodrugs for the two SEAKER systems and evaluate their conversion to the active compounds using recombinant enzymes in vitro. Compounds such as carfilzomib and panobinostat are associated with on-target off-site toxicity when administered for the treatment of multiple myeloma. Tumor targeting “epoxySEAKER” or “onSEAKER” cells will localize the secretion of synthetic enzyme to the tumor site, allowing systemic administration of non-toxic prodrug, subsequent in situ compound synthesis and reduced off-site toxicity demonstrated by the target compounds. The additive therapeutic effect of the CAR-T cells and small-molecules will increase the effectiveness of treatment and may expand the target scope of CAR-T cell therapy.