Mucosal Chemokines and CD8+ T Cell Immunity to Genital Herpes

项目摘要/摘要 粘膜组织是持续接触感染性病原体的前线屏障。正在开发和 维持保护性的粘膜组织驻留记忆T细胞(TRM细胞)对于免疫监测是必要的。 然而，控制粘膜TRM细胞归巢和维持的机制尚不清楚，而且很可能 不同于传统的循环效应记忆细胞和中央记忆细胞的调控。一个 目前公认的范式是粘膜趋化因子(即CCL25、CCL28、CXCL14和CXCL17)发挥作用 在粘膜组织中动员TRM细胞的关键作用，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)所涉及的粘膜趋化因子的身份；(2)它们的 细胞来源；以及(3)它们调节抗-DNA动员的细胞和分子机制。 病毒黏膜CD8+TRM细胞。该方案使用单纯疱疹病毒2型(HSV-2)作为模型病毒病原体 阐明HSV特异性CD8+TRM细胞在阴道内动员的潜在机制 粘膜组织。我们已发表的和初步的数据表明：(A)HSV特异性记忆的数量增加 CD62低CCR7lowCD103高CD8+TRM细胞和CXCR8+CD8+T细胞存在于HSV阴道黏膜中。 2感染的无症状小鼠与有症状的小鼠比较；(B)粘膜趋化因子CXCL17和CCL28 在HSV-2感染的无症状小鼠的阴道粘膜组织中高表达，但没有明显的 生殖器疱疹疾病；(C)无症状小鼠阴道黏膜中CD8+TRM细胞表达CXCR3 (T细胞趋化因子受体CXCL9和CXCL10)、CXCR8和CCR10(趋化因子受体 分别为CXCL17和CCL28)；(D)阴道内注射吸引T细胞的趋化因子CXCL9和 CXCL10与CXCR8+CD8+、CCR10+CD8+TRM细胞向阴道粘膜募集增加有关 和(E)外源性CXCL9和CXCL10显著增加CXCR3的表达， CXCR8和CCR10受体在阴道粘膜驻留的CD8+TRM细胞上的表达。基于这些发现，我们 假设CXCL17和CCL28在阴道粘膜组织的归巢和维持中起关键作用- 常驻CD8+TRM细胞，保护生殖器疱疹。我们的具体目标包括：目标1将确定 CXCL17和CCL28在阴道粘膜中的细胞来源及调节其表达的介质目标 2将研究CXCL17和CCL28粘膜趋化因子的作用，并研究对局部病毒抗原的需求 在阴道粘膜内CD8+TRM细胞的发育、维持和扩张中的表达。目标3将 开发一种新的“优质、拉动和保持”疫苗策略，以增加阴道粘膜的大小和维护- 常驻CD8+TRM细胞，防止生殖器疱疹。这是基于阴道内的三个连续步骤 给予：(1)CD8+T细胞表位(PRIME)；(2)CXCL9和/或CXCL10 T细胞趋化因子(Pull)； (3)CXCL17和/或CCL28粘膜趋化因子(Keep)。顺利完成这项基本和 翻译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.