CPAF induced CD4+ T cell mediated immunity against Chlamydia

描述（由申请人提供）：目前尚无针对沙眼衣原体的许可疫苗，而沙眼衣原体是全球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引起严重的后遗症，如盆腔炎、异位妊娠和不孕症。一种衣原体分泌的蛋白，被称为CPAF（衣原体蛋白酶/蛋白酶体样活性因子），负责降解宿主MHC转录因子RFX5和USF1。因此，抑制CPAF活性将是阻断衣原体逃避免疫识别的一种可行的疫苗接种策略。我们现在已经提供了直接证据来证明这种方法的有效性，使用重组(r)CPAF和IL-12在鼻内（in）给药系统中。与模拟免疫（PBS）小鼠相比，鼻内接种rCPAF和IL-12诱导了大量抗原特异性IFN-3的产生，显著减少了阴道内（阴道）衣原体攻击时的细菌脱落，并显著加速了感染的消退。重要的是，接种rCPAF+IL-12疫苗的小鼠对衣原体感染的病理后果有保护作用，包括输卵管系膜炎症、输卵管积水和输卵管扩张。rCPAF+ il -12介导的衣原体感染的解决和对炎症病理的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。基于我们值得注意的证据，我们假设“CPAF疫苗通过抗原特异性IFN-3分泌CD4+ t细胞在局部吞噬细胞的参与下增强上生殖道内的细菌清除，从而促进生殖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；(1)检验接种CPAF疫苗对生殖道衣原体感染后生殖力保存的直接影响；(2)确定CPAF接种诱导的上生殖道内抗原特异性CD4+ T细胞浸润与衣原体生物减少的关系；(3)探讨IFN-3产生CPAF特异性CD4+ T细胞增强细菌清除和预防衣原体感染相关泌尿生殖道病理发展的机制。公共卫生相关性：目前尚无针对沙眼衣原体的许可疫苗，而沙眼衣原体是世界范围内细菌性传播疾病的主要原因。利用小鼠生殖器衣原体感染模型，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诱导了抗原特异性IFN-3的产生，显著减少了细菌的脱落，并诱导了对衣原体感染病理后果的保护，包括输卵管系膜炎症、输卵管积水和输卵管扩张的发展。该建议将进一步研究CPAF疫苗接种对预防不孕症的功效，并为这种保护性免疫的性质提供机制见解。

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.