Abstract：
Interleukin (IL)18 is a potent pro-inflammatory cytokine that is activated upon caspase 1 cleavage of the latent precursor, pro-IL18. Therapeutic T cell armoring with IL18 promotes autocrine stimulation and positive modulation of the tumor microenvironment (TME). However, existing strategies are imperfect since they involve constitutive/poorly regulated activity or fail to modify the TME. Here, we have substituted the caspase 1 cleavage site within pro-IL18 with that preferred by granzyme B, yielding GzB-IL18. We demonstrate that GzB-IL18 is constitutively released but remains functionally latent unless chimeric antigen receptor (CAR) T cells are activated, owing to concomitant granzyme B release. Armoring with GzB-IL18 enhances cytolytic activity, proliferation, interferon (IFN)-γ release, and anti-tumor efficacy by a similar magnitude to constitutively active IL18. We also demonstrate that GzB-IL18 provides a highly effective armoring strategy for γδ CAR T cells, leading to enhanced metabolic fitness and significant potentiation of therapeutic activity. Finally, we show that constitutively active IL18 can unmask CAR T cell-mediated cytokine release syndrome in immunocompetent mice. By contrast, GzB-IL18 promotes anti-tumor activity and myeloid cell re-programming without inducing such toxicity. Using this stringent system, we have tightly coupled the biological activity of IL18 to the activation state of the host CAR T cell, favoring safer clinical implementation of this technology.
摘要：
白细胞介素（IL）18是一种有效的促炎细胞因子，在潜伏前体的半胱天冬酶1裂解后被激活，亲IL18。具有IL18的治疗性T细胞铠装促进肿瘤微环境(TME)的自分泌刺激和正调节。然而,现有的策略是不完善的，因为它们涉及构成性/监管不力的活动，或无法修改TME。这里,我们将pro-IL18中的caspase1切割位点替换为颗粒酶B优选的位点，产生GZB-IL18。我们证明GzB-IL18是组成型释放的，但仍然是功能潜伏的，除非CAR-T细胞被激活。由于伴随的颗粒酶B的释放。使用GzB-IL18增强细胞溶解活性，扩散,IFN-γ释放和抗肿瘤功效与组成型活性IL18相似。我们还证明GzB-IL18为γδCAR-T细胞提供了一种高效的铠装策略，导致代谢适应性增强和治疗活性的显着增强。最后,我们表明,在免疫活性小鼠中,具有组成活性的IL18可以揭示CAR-T细胞介导的细胞因子释放综合征.相比之下,GzB-IL18促进抗肿瘤活性和骨髓细胞重编程而不诱导这种毒性。使用这个严格的系统，我们已经将IL18的生物活性与宿主CAR-T细胞的活化状态紧密耦合，有利于更安全的临床实施这项技术。
