Host Immune Responses to Chlamydia trachomatis Candidate Vaccine Antigens and their Association with Clinical Correlates of Protective Immunity in Women

预防沙眼衣原体(CT)感染是公共卫生的优先事项，因为它会导致生殖 后遗症。由于CT控制程序并未降低感染率，因此需要接种CT疫苗。我们的长期合作 目标是产生将推动CT疫苗开发的知识。CT疫苗的一个障碍 研究进展已经确定了人类免疫和临床保护的相关性。我们展示了CT- 特异性系统CD4IFN-g是女性免疫保护和自发清除 治疗前CT感染和治疗后无再感染是预防的临床相关因素。使用 关于女性CT特异性粘膜细胞免疫反应的稀疏数据，我们开发了一种新的方法 使用来自月经血(MB)的粘膜单个核细胞(MMC)研究这些反应。另一个 CT疫苗开发的障碍一直是识别诱导保护性免疫的CT抗原。使用 免疫蛋白质组学方法，Brunham博士的实验室发现了五种CT外膜蛋白(OMP) 引起强烈的T辅助细胞1型(Th1)反应。他们测试了一种CT和鼠疫杆菌亚单位疫苗 将这些OMPS与Th1极化佐剂相结合，发现它加速了小鼠的感染清除。 这些CT OMP的潜在免疫原性和对CT疫苗的需求为以下方面提供了强有力的理由 将这些有希望的CT抗原和其他抗原的免疫研究扩展到人类。我们的主要目标是 建议(针对FOA PA-19-096)研究对前景看好的CT疫苗的细胞和抗体反应 候选抗原。我们的假设是针对候选CT抗原的Th1细胞因子反应将是 与临床保护相关，并可能与抗CT的功能性抗体反应相关 生物体(EBS)。我们的研究有三个目标：目标1-研究全身细胞和体液免疫反应 目的：探讨CT疫苗候选抗原及其与预防女性CT感染的临床相关性。 自然清除与持续感染沙眼衣原体感染者外周血单个核细胞的比较 没有CT再感染的女性与有CT再感染的女性相比，很有希望的CT疫苗候选将在体外受到刺激 通过细胞内细胞因子染色(ICS)检测抗原和CD4、CD8T细胞应答。Sera将会是 检测针对CT的免疫球蛋白抗原和对CT EBS的功能性抗体反应。目的2-评估粘膜T细胞 CT疫苗候选抗原诱导的抗体应答及其与临床相关性的研究 保护女性免受CT感染。从Aim 1参与者开始，MB来源的MMC将通过CT进行体外刺激 免疫印迹法检测抗原和CD4、CD8T细胞应答。针对CT抗原的粘膜抗体将是 测试过。目的3-使用体外人树突状细胞/CD4T细胞共培养方法(模拟系统)证实 女性CT疫苗候选抗原的抗原性和免疫原性来自CT天真的PBMC 妇女将在模拟系统中用于评估抗原性和免疫原性(当给予佐剂时)。 候选CT抗原。研究结果可能导致一期研究的CT疫苗配方。

Prevention of Chlamydia trachomatis (CT) infection is a public health priority because it causes reproductive sequelae. Since CT control programs have not reduced infection rates, a CT vaccine is needed. Our long-term goal is to generate knowledge that will advance CT vaccine development. One obstacle to CT vaccine development had been identifying immune and clinical correlates of protection in humans. We showed that CT- specific systemic CD4+ IFN-g is a correlate of immune protection in women and that spontaneous clearance of CT infection before treatment and absence of reinfection after treatment are clinical correlates of protection. With sparse data on CT-specific mucosal cellular immune responses in women, we developed a novel approach for studying these responses using mucosal mononuclear cells (MMCs) from menstrual blood (MB). Another obstacle in CT vaccine development has been identifying CT antigens that induce protective immunity. Using an immunoproteomic approach, Dr. Brunham’s laboratory identified five CT outer membrane proteins (OMPs) that elicited strong T helper type 1 (Th1) responses. They tested a CT and C. muridarum subunit vaccine that combined these OMPs with a Th1 polarizing adjuvant and found it accelerated infection clearance in mice. The potential immunogenicity of these CT OMPs and need for a CT vaccine provides strong rationale for extending immune studies of these promising CT antigens and others to humans. The major objective of our proposal (in response to FOA PA-19-096) is to study cellular and antibody responses to promising CT vaccine candidate antigens. Our hypothesis is that Th1 cytokine responses against candidate CT antigens will be associated with clinical correlates of protection and may correlate with functional antibody responses against CT organisms (EBs). Our study has 3 aims: Aim 1 - Investigate systemic cellular and humoral immune responses to candidate CT vaccine antigens and their association with clinical correlates of protection against CT in women. Peripheral blood mononuclear cells (PBMCs) from women with spontaneously cleared vs. persisting CT infection and women without vs. with CT reinfection will be stimulated ex vivo with promising CT vaccine candidate antigens and CD4+ and CD8+ T cell responses measured by intracellular cytokine staining (ICS). Sera will be tested for IgG to CT antigens and functional antibody responses to CT EBs. Aim 2 - Evaluate mucosal T cell and antibody responses induced by candidate CT vaccine antigens and their association with clinical correlates of protection against CT in women. From Aim 1 participants, MMCs from MB will be stimulated ex vivo with CT antigens and CD4+ and CD8+ T cell responses measured by ICS. Mucosal antibodies to CT antigens will be tested. Aim 3 - Use an in vitro human dendritic cell / CD4+ T cell co-culture method (MIMIC system) to confirm antigenicity and immunogenicity of promising candidate CT vaccine antigens in women. PBMCs from CT naïve women will be used in the MIMIC system to evaluate antigenicity and immunogenicity (when given with adjuvant) of the candidate CT antigens. Study findings may lead to a CT vaccine formulation for a phase I study.