溶脲脲原体编码蛋白线性表位鉴定及多表位肽避孕疫苗的研究

Rapid growth of population and high rate of abortion due to unintended pregnancies are always major problems influencing the economic development, national health, and social harmony of our country. Therefore, seeking safe and effective contraceptive methods has been one of the important research directions in the field of human reproductive health. Ureaplasma urealyticum ( Uu ) infection，which can cause high level of serum and/or semen antisperm antibody, is closely related to male infertility. In order to research and produce multi-epitope peptide contraceptive vaccines, we choose three Uu encoding proteins named Uu474, UreG, and Uu436, which exist cross-reacting antigens with sperm protein Izumo, nuclear autoantigenic sperm protein (tNASP) and sperm equatorial segment protein (ESP) respectively, as target proteins to develop the linear epitomics. In this study, the improved biosynthetic peptide method will be performed to map all linear epitopes and their minimal motifs on three target proteins from Uu and to determine the conseved epitopes and/or antibody-neutralizing epitopes among mapped epitopes by comparison of homologous and above-mentioned sperm protein sequences. At the basis of above epitope mapping, two or three multi-epitope peptide vaccines will be constructed. Animal experiments will be carried out in vitro and in vivo for testing the immugenicity, effectiveness, safety and reversibility of the vaccines. This study will provide a new train of thought and new method for developing ideal contraceptive vaccine.

人口增长过快和因非意愿怀孕而导致的流产率居高不下,始终是影响我国经济发展、国民健康和社会和谐的重大问题。因此,寻求安全有效的避孕方法一直是人类生殖健康领域重要的研究方向之一。溶脲脲原体（Ureaplasma urealyticum，Uu）感染可导致不育患者血清和/或精液中抗精子抗体水平显著升高,与男性不育密切相关。本课题为了研制多表位肽避孕疫苗，选择Uu编码蛋白中与精子蛋白Izumo、细胞核自身抗原精子蛋白（tNASP）和精子赤道段蛋白（ESP）分别存在交叉反应抗原的Uu474、UreG和Uu436 作为靶蛋白，开展线性表位组学研究；鉴定出上述三个Uu靶蛋白的全部线性表位及其最小基序；通过同源蛋白找出其中保守性表位和/或抗体中和性表位；构建2-3个多表位肽疫苗，通过动物体内外实验研究疫苗的免疫原性及其免疫避孕的有效性、安全性和可逆性，为寻找理想的节育疫苗提供新思路和新方法。

人口增长过快和因非意愿怀孕而导致的流产率居高不下，始终是影响我国经济发展、国民健康与社会和谐的重大问题。因此，寻求安全有效的避孕方法一直是人类生殖健康领域重要的研究方向之一。溶脲脲原体（Ureaplasma urealyticum，Uu）感染可导致不育患者血清和/或精液中抗精子抗体水平显著升高，与男性不育密切相关。本项目原先申请金额80万，后批准为小额资助（一年期，16万）课题，故基于前期实验，我们选择Uu编码蛋白中与精子蛋白存在交叉反应抗原的UreG作为靶蛋白，开展线性表位组学研究，鉴定了UreG蛋白上的线性表位及其最小基序，它们分别为：KRPLIIG， RILLNT， DLAPY， LKSR和 RLQLAL，其中KRPLIIG表位免疫原性最强，LKSR表位免疫原性最弱；其次，通过生物信息学研究分析发现，表位LKSR与精子蛋白间存在交叉反应性表位；最后，经动物实验证实KRPLIIG表位和LKSR表位具有抗生育作用，可作为免疫避孕疫苗研究的靶抗原。