Generation of CD8+ Tissue-Resident Memory T cell response during Yersinia pseudotuberculosis foodborne infection

项目摘要/摘要 驻留在屏障组织中的组织驻留记忆T(TRM)细胞在病原体之后立即做出反应 相遇。诱导TRM细胞已成为对抗传染病和疫苗开发的优先事项 在癌症免疫治疗方面。减毒活革兰氏阴性杆菌假结核耶尔森菌(YPTB) 将在这里作为一种新的疫苗载体进行评估，以产生抗原特异性的肠道CD8+TRM细胞。作为稀有的 病原体Yptb在免疫能力强的人中主要引起自限性肠系膜淋巴结炎，并且是 可以用抗生素治疗的。Yptb亚致死感染C57BL/6小鼠后产生大的H-2kb限制性CD8+T细胞 细菌表位YopE69-77的特异性细胞反应。在食源性感染后，Yptb的两个不同亚群- 在肠道组织中发现了特异性的CD8+TRM细胞：散在分布的CD103+和聚集的CD103 细胞。CD103+细胞依赖于转化生长因子-b(TGFb)，CD103neg细胞需要 干扰素-b(IFNb)和白介素12(IL-12)，主要由CCR2依赖产生的炎性细胞因子 细胞。 Yptb的几个独特特征表明，这种以前被忽视的病原体处于有利地位 将其转化为疫苗载体的位置。Yptb利用3型分泌系统(T3SS)注射一组 6-7毒性效应蛋白，统称为YOP，从细菌直接进入真核细胞的胞浆 在感染期间。通过Yptb T3SS注入这些YOP效应器依赖于接触，并且 小鼠感染时，高比例的吞噬细胞是靶标。因此，基于Yptb的疫苗 载体将抗原蛋白直接导入吞噬细胞抗原提呈细胞的胞浆，而不需要 需要操纵真核细胞的基因组或转录组。建议在这里进行研究以启动 调查了解两种类型TRM代的细菌和细胞决定因素。此外, 由于YOP效应器干扰宿主免疫反应，因此将努力减弱Yptb- 以疫苗载体为基础，通过灭活相关的YOP效应器来增加其免疫原性。 此外，由于细胞毒性CD8+T细胞反应需要控制Yptb，即使在保护性存在的情况下 抗体反应，减毒的Yptb疫苗载体可以重复引入以诱导 具有额外抗原特异性的TRM细胞将被评估。完成这里提出的研究将设置 为开发肠道TRM细胞生成迫切需要的新型减毒活疫苗奠定了基础。

Project Summary/Abstract The tissue resident memory T (TRM) cells that reside at barrier tissues respond immediately following pathogen encounter. Eliciting TRM cells has become a priority in vaccine development to combat infectious diseases and in cancer immunotherapy. Live attenuated Gram-negative bacterial pathogen Yersinia pseudotuberculosis (Yptb) will be evaluated here as a new vaccine vector to produce antigen-specific intestinal CD8+ TRM cells. As a rare pathogen, Yptb causes mostly self-limited mesenteric lymphadenitis in immune competent humans and is treatable with antibiotics. Sub-lethal infection with Yptb in C57BL/6 mice elicits a large H-2Kb-restricted CD8+ T cell response specific to bacterial epitope YopE69-77. Following foodborne infection, two different subsets of Yptb- specific CD8+ TRM cells were identified in intestinal tissues: the scattered CD103+ and the clustered CD103neg cells. The CD103+ cells depend on transforming growth factor-b (TGFb) and the CD103neg cells require interferon-b (IFNb) and interleukin-12 (IL-12), inflammatory cytokines mostly generated from CCR2-dependent cells. Several unique characteristics of Yptb suggest that this previously overlooked pathogen is at an advantageous position to be transformed into a vaccine vector. Yptb utilizes a type 3 secretion system (T3SS) to inject a set of 6-7 toxic effector proteins, collectively called Yops, from the bacterium directly into the cytosol of eukaryotic cells during infection. Injection of these Yop effectors through the Yptb T3SS is contact dependent and following mouse infection, a high percentage of phagocytes are among the targets. Therefore, the Yptb-based vaccine vector introduces antigenic proteins directly into the cytosol of phagocytic antigen-presenting cells without the need to manipulate the genome or transcriptome of eukaryotic cells. Studies are proposed here to initiate investigation to understand the bacterial and cellular determinants of the two types of TRM generation. In addition, because the Yop effectors interfere with host immune responses, efforts will be made to attenuate the Yptb- based vaccine vector and increase its immunogenicity through inactivation of the relevant Yop effectors. Moreover, because cytotoxic CD8+ T cell response is required to control Yptb even in the presence of protective antibody response, the possibility that the attenuated Yptb vaccine vector can be introduced repeatedly to elicit TRM cells with additional antigenic specificity will be evaluated. Accomplishing the studies proposed here will set the foundation to develop a new type of live attenuated vaccine that is urgently needed for gut TRM cell generation.