CPAF induced CD4+ T cell mediated immunity against Chlamydia

描述（由申请人提供）：目前还没有针对沙眼衣原体的许可疫苗，沙眼衣原体是全世界细菌性传播疾病的主要原因。未经治疗的生殖器衣原体感染会导致严重的后遗症，例如盆腔炎、宫外孕和不孕症。衣原体分泌的蛋白质，称为 CPAF（衣原体蛋白酶/类蛋白酶体活性因子），负责宿主 MHC 转录因子 RFX5 和 USF1 的降解。因此，抑制 CPAF 活性将是阻止衣原体逃避免疫识别的可行疫苗接种策略。我们现在提供了直接证据来证明在鼻内 (i.n.) 递送系统中使用重组 (r)CPAF 和 IL-12 的这种方法的有效性。与模拟免疫 (PBS) 小鼠相比，鼻内接种 rCPAF 和 IL-12 诱导了强劲的抗原特异性 IFN-3 产生，显着减少了阴道内 (i.vag.) 衣原体攻击时的细菌脱落，并显着加速了感染的消退。重要的是，接种 rCPAF IL-12 的小鼠表现出对衣原体感染病理后果的保护作用，包括输卵管系膜炎症、输卵管积水和输卵管扩张。 rCPAF IL-12 介导的衣原体感染消退和炎症病理保护高度依赖于内源性 IFN-3 的产生和抗原特异性 CD4 T 细胞的作用。基于我们的大量证据，我们假设“CPAF 疫苗接种可在局部吞噬细胞的参与下，通过分泌抗原特异性 IFN-3 的 CD4 T 细胞增强上生殖道内的细菌清除，从而促进生育能力的保存并减少生殖器衣原体感染后的炎症病理”。我们将通过以下方式检验这一假设： (1) 检查 i.n 的直接影响。 CPAF 疫苗接种对生殖器衣原体攻击后保留生育能力的影响； (2)确定CPAF疫苗接种诱导的上生殖道内衣原体生物的减少与抗原特异性CD4 T细胞浸润之间的关系； (3) 研究产生 IFN-3 的 CPAF 特异性 CD4 T 细胞增强细菌清除并预防与衣原体感染相关的泌尿生殖病理学发展的机制。公共卫生相关性：目前还没有针对沙眼衣原体的许可疫苗，沙眼衣原体是全球细菌性传播疾病的主要原因。使用生殖器衣原体感染的小鼠模型，鼻内接种（重组衣原体蛋白酶/蛋白酶体样活性因子）CPAF和IL-12可诱导强劲的抗原特异性IFN-3产生，显着减少细菌脱落并诱导预防衣原体感染的病理后果，包括输卵管系膜炎症以及输卵管积水和输卵管扩张的发生。该提案将进一步检验 CPAF 疫苗接种预防不孕不育的功效，并为这种保护性免疫的本质提供机制上的见解。

DESCRIPTION (provided by applicant): There currently is no licensed vaccine against Chlamydia trachomatis, the leading cause of bacterial sexually transmitted disease worldwide. Untreated genital chlamydial infection cause serious sequelae such as pelvic inflammatory disease, ectopic pregnancy, and infertility. A Chlamydia-secreted protein, designated as CPAF (chlamydial protease/proteasome-like activity factor), is responsible for degradation of the host MHC transcription factors RFX5 and USF1. Inhibiting CPAF activity will therefore be a feasible vaccination strategy for blocking chlamydial evasion of immune recognition. We have now provided direct evidence to demonstrate the effectiveness of such an approach using recombinant (r)CPAF and IL-12 in an intranasal (i.n.) delivery system. Intranasal vaccination with rCPAF and IL-12 induced robust antigen-specific IFN-3 production, significantly reduced bacterial shedding upon intravaginal (i.vag.) chlamydial challenge and significantly accelerated the resolution of infection compared to mock-immunized (PBS) mice. Importantly, rCPAF+IL-12 vaccinated mice exhibited protection against pathological consequences of chlamydial infection, including mesosalpingeal inflammation and development of hydrosalpinx and oviduct dilation. The rCPAF+IL-12-mediated resolution of chlamydial infection and protection against inflammatory pathology was highly dependent on endogenous IFN-3 production and the action of antigen-specific CD4+ T cells. Based on our notable body of evidence, we hypothesize that "CPAF vaccination promotes preservation of fertility and reduces inflammatory pathology after genital Chlamydia infection by enhancing bacterial clearance within the upper genital tract via antigen-specific IFN-3 secreting CD4+ T-cells with the participation of local phagocytic cells". We will test this hypothesis by; (1) Examining the direct effect of i.n. CPAF vaccination on the preservation of fertility after genital chlamydial challenge; (2) Determine the relationship between the reduction in chlamydial organisms and the infiltration of antigen-specific CD4+ T cells within the upper genital tract induced by CPAF vaccination; (3) Investigating the mechanism(s) by which IFN-3 producing CPAF specific CD4+ T cells enhance bacterial clearance and prevent the development of urogenital pathology associated with chlamydial infection. PUBLIC HEALTH RELEVANCE: There currently is no licensed vaccine against Chlamydia trachomatis, the leading cause of bacterial sexually transmitted disease worldwide. Using a murine model of genital chlamydial infection, intranasal vaccination with (recombinant chlamydial protease/proteasome-like activity factor) CPAF and IL-12 induced robust antigen-specific IFN-3 production, significantly reduced bacterial shedding and induced protection against pathological consequences of chlamydial infection, including mesosalpingeal inflammation and development of hydrosalpinx and oviduct dilation. This proposal will further examine the efficacy of CPAF vaccination against the prevention of infertility and provide mechanistic insight into the nature of this protective immunity.