Mucosal Chemokines and CD8+ T Cell Immunity to Genital Herpes

项目总结/摘要 粘液组织是持续暴露于感染性病原体的前线屏障。发展中国家和 维持保护性粘膜组织驻留记忆T细胞（TRM细胞）对于免疫监视是必需的。 然而，控制粘膜TRM细胞归巢和维持的机制是未知的， 与调节常规循环效应记忆（TEM）和中枢记忆（TCM）细胞的那些不同。一 目前接受的范例是粘膜趋化因子（即，CCL 25、CCL 28、CXCL 14和CXCL 17）发挥 在动员粘膜组织中的TRM细胞中起关键作用，并且可能独立于局部抗原识别而发生。 然而，仍然存在几个主要的差距，包括：（1）涉及的粘膜趋化因子的身份;（2）它们的作用机制。 细胞来源;和（3）细胞和分子机制，通过它们调节动员抗- 病毒粘膜CD 8 + TRM细胞。该建议使用单纯疱疹病毒2型（HSV-2）作为模型病毒病原体 阐明调节阴道中HSV特异性CD 8 + TRM细胞动员的潜在机制， 粘膜组织我们发表的和初步的数据表明：（A）HSV特异性记忆的数量增加 CD 62低CCR 7低CD 103高CD 8 + TRM细胞和CXCR 8 + CD 8 + T细胞存在于HSV-1感染者的阴道粘膜中。 与有症状的小鼠相比，2只感染的无症状小鼠;（B）粘液样细胞趋化因子CXCL 17和CCL 28 在HSV-2感染的无症状小鼠的阴道粘膜组织中高度表达， 生殖器疱疹疾病;（C）存在于无症状小鼠阴道粘膜中的CD 8 + TRM细胞表达CXCR 3 (the T细胞吸引趋化因子CXCL 9和CXCL 10的受体）、CXCR 8和CCR 10（T细胞吸引趋化因子CXCL 9和CXCL 10的受体）。 （D）阴道内施用T细胞吸引趋化因子CXCL 9和CXCL 28）; CXCL 10与CXCR 8 + CD 8+、CCR 10 + CD 8 + TRM细胞向阴道粘膜的募集增加相关 （E）外源性CXCL 9和CXCL 10显著增加CXCR 3的表达， CXCR 8和CCR 10受体。基于这些发现，我们 假设CXCL 17和CCL 28在阴道粘膜组织归巢和维持中起关键作用- 常驻CD 8 + TRM细胞，可预防生殖器疱疹。我们的具体目标包括：目标1将确定 阴道粘膜中CXCL 17和CCL 28的细胞来源以及调节其表达的介质。目的 2将研究CXCL 17和CCL 28粘膜趋化因子的作用，并研究是否需要局部病毒抗原 在阴道粘膜内发育、维持和扩增CD 8 + TRM细胞中的表达。目标3将 开发一种新的“初免、拉取和保留”疫苗策略，以增加阴道粘膜的大小和维持， 常驻CD 8 + TRM细胞可预防生殖器疱疹。这是基于阴道内注射的三个连续步骤 施用：（1）CD 8 + T细胞表位（初免）;（2）CXCL 9和/或CXCL 10 T细胞吸引趋化因子（拉取）; 和（3）CXCL 17和/或CCL 28粘膜趋化因子（keep）。成功完成这一基本和 转化研究项目将为开发有效的粘膜疱疹疫苗铺平道路。

PROJECT SUMMARY/ABSTRACT Mucosal tissues are frontline barriers that are continuously exposed to infectious pathogens. Developing and maintaining protective mucosal tissue-resident memory T cells (TRM cells) is necessary for immune surveillance. However, the mechanisms controlling homing and maintenance of mucosal TRM cells are unknown and likely distinct from those regulating conventional circulating effector memory (TEM) and central memory (TCM) cells. A currently accepted paradigm is that mucosal chemokines (i.e., CCL25, CCL28, CXCL14, and CXCL17) play a crucial role in mobilizing TRM cells in mucosal tissues, and may occur independent of local antigen recognition. However, several major gaps remain, including: (1) the identity of the mucosal chemokines involved; (2) their cellular source; and (3) the cellular and molecular mechanisms through which they regulate mobilization of anti- viral mucosal CD8+ TRM cells. This proposal uses herpes simplex virus type 2 (HSV-2) as a model viral pathogen to elucidate the underlying mechanisms that regulate mobilization of HSV-specific CD8+ TRM cells in the vaginal mucosal tissue. Our published and preliminary data indicate that: (A) Elevated numbers of HSV-specific memory CD62LlowCCR7lowCD103highCD8+ TRM cells and CXCR8+CD8+ T cells are present in the vaginal mucosa of HSV- 2 infected asymptomatic mice as compared to symptomatic mice; (B) Mucosal chemokines CXCL17 and CCL28 are highly expressed in the vaginal mucosal tissues of HSV-2-infected asymptomatic mice, with no apparent genital herpes disease; (C) CD8+ TRM cells that reside in vaginal mucosa of asymptomatic mice express CXCR3 (the receptor for T cell-attracting chemokines CXCL9 and CXCL10),CXCR8, and CCR10 (the receptors for CXCL17 and CCL28, respectively); (D) Intravaginal administration of T cell-attracting chemokines CXCL9 and CXCL10 is associated with increased recruitment of CXCR8+CD8+, CCR10+CD8+ TRM cells to the vaginal mucosa of asymptomatic mice; and (E) Exogenous CXCL9 and CXCL10 significantly increased expression of CXCR3, CXCR8, and CCR10 receptors on vaginal mucosa-resident CD8+ TRM cells. Based on these findings, we hypothesize that CXCL17 and CCL28 play a crucial role in homing and maintenance of vaginal mucosal tissue- resident CD8+ TRM cells, which protect from genital herpes. Our Specific Aims include: Aim 1 will identify the cellular sources of CXCL17 and CCL28 in vaginal mucosa and the mediators that regulate their expression. Aim 2 will investigate the role of CXCL17 and CCL28 mucosal chemokines and study the need for local viral antigen expression in developing, maintaining, and expanding CD8+ TRM cells within the vaginal mucosa. Aim 3 will develop a novel “prime, pull, and keep” vaccine strategy to increase the size and maintenance of vaginal mucosa- resident CD8+ TRM cells to protect against genital herpes. This is based on three sequential steps of intravaginal administration of: (1) CD8+ T cell epitopes (prime); (2) CXCL9 and/or CXCL10 T-cell attracting chemokines (pull); and (3) CXCL17 and/or CCL28 mucosal chemokines (keep). Successful completion of this basic and translational research project will pave the way towards the development of an effective mucosal herpes vaccine.