Transcutaneous and oral-transcutaneous cholera immunization with TcpA and Peru15

描述（由申请人提供）：霍乱弧菌是引起霍乱的B类病原体。人们对霍乱弧菌的保护性免疫知之甚少，而高效霍乱疫苗的开发一直存在问题。我们有初步证据表明，在野生型霍乱之后，针对毒素共调节菌毛（TcpA）的主要亚基的免疫反应是突出的，TcpA是霍乱弧菌在人类肠道定植所需的一种毒力因子。TcpA在体内感染时表达；肠外和口服灭活霍乱疫苗不含TcpA，肠外和口服灭活霍乱疫苗仅在相对较短的时间内（30-80%；3-6个月）对霍乱具有中等保护作用。此外，我们有初步证据表明，口服减毒霍乱活疫苗（如秘鲁15）免疫后，抗tcpa反应并不突出，尽管接种疫苗后可诱导显著的杀弧菌免疫反应。我们也有初步证据表明，经皮接种TcpA具有高度的免疫原性，并且联合免疫包括用减毒霍乱活疫苗接种粘膜（口服）疫苗，然后经皮接种纯化抗原增强，可诱导非常强大的粘膜和全身免疫反应。我们假设口服Peru15免疫和经皮经纯化TcpA增强会诱导显著的保护性粘膜和全身免疫反应，更接近于野生型霍乱后发生的情况。在这个修订后的R21开发项目中，我们有两个具体目标：(1)进一步研究经皮应用TcpA作为小鼠模型中预防霍乱的保护性免疫原的潜力（评估剂量、时间、间隔和安全性问题）。(2)研究口服Peru15和经皮经皮纯化TcpA联合免疫小鼠，在小鼠攻毒模型中测定全身和粘膜免疫应答和对霍乱的保护作用。该项目将提供关键的初步信息，以确定诱导抗tcpa反应是否可以补充目前可用的霍乱疫苗诱导的免疫反应，以及粘膜-经皮联合免疫策略是否可以诱导突出的粘膜和全身免疫反应，以保护粘膜病原体。本研究R21项目产生的数据将为更详细的联合免疫机制免疫学分析奠定基础，并为后续的人体评价提供便利，并有可能为针对粘膜病原体的联合免疫方案的新范式奠定基础。相关性：霍乱弧菌是引起霍乱的B类病原体。本项目将研究针对霍乱的粘膜-经皮联合免疫策略是否能诱导突出的粘膜和全身免疫反应，以保护黏膜病原体。本研究R21项目产生的数据将为更详细的联合免疫机制免疫学分析奠定基础，并为后续的人体评价提供便利，并有可能为针对粘膜病原体的联合免疫方案的新范式奠定基础。

DESCRIPTION (provided by applicant): Vibrio cholerae is the cause of cholera and a category B agent. Protective immunity to V. cholerae is poorly understood, and development of highly effective cholera vaccines has been problematic. We have preliminary evidence that following wild type cholera, immune responses are prominent against the main subunit of toxin co-regulated pilus (TcpA), a V. cholerae virulence factor required for intestinal colonization of humans. TcpA is expressed in vivo during infection; parenteral and oral killed cholera vaccines do not contain TcpA, and parenteral and killed oral cholera vaccines are only moderately protective against cholera for relatively short periods of time (30-80%; 3-6 months). In addition, we have preliminary evidence that anti-TcpA responses are not prominent following oral immunization with live attenuated cholera vaccines (such as Peru15), despite induction of prominent vibriocidal immune responses following vaccination. We also have preliminary evidence that transcutaneous immunization with TcpA is highly immunogenic, and that combination immunization that includes mucosal (oral) vaccination with live attenuated cholera vaccines followed by transcutaneous boosting with purified antigen induces very robust mucosal and systemic immune responses. We hypothesize that oral immunization with Peru15 and transcutaneous boosting with purified TcpA would induce prominent and protective mucosal and systemic immune responses that more closely mirror what occurs after wild type cholera. In this revised R21 developmental project, we have two Specific aims: (1) To further investigate the potential of transcutaneously applied TcpA to act as a protective immunogen against cholera in a mouse model (evaluating issues of dosing, timing, interval, and safety). (2) To investigate combination immunization of oral priming with Peru15 and transcutaneous boosting with purified TcpA in mice, measuring systemic and mucosal immune responses and protection against cholera in the mouse challenge model. This project would provide pivotal preliminary information on whether induction of anti-TcpA responses would complement immune responses induced by a currently available cholera vaccine, and whether mucosal-transcutaneous combination immunization strategies can induce prominent mucosal and systemic immune responses protective against a mucosal pathogen. Data generated by this developmental R21 project would lay the foundation for a more detailed mechanistic immunological analysis of combination immunization, as well as facilitate subsequent evaluation in humans, and could possibly lay the foundation for a new paradigm of combination immunization regimens against mucosal pathogens. Relevance: Vibrio cholerae is the cause of cholera and a category B agent. This project would investigate whether mucosal-transcutaneous combination immunization strategies against cholera can induce prominent mucosal and systemic immune responses protective against a mucosal pathogen. Data generated by this developmental R21 project would lay the foundation for a more detailed mechanistic immunological analysis of combination immunization, as well as facilitate subsequent evaluation in humans, and could possibly lay the foundation for a new paradigm of combination immunization regimens against mucosal pathogens.