J亚型禽白血病病毒诱导鸡CD4+T细胞特异性应答反应机制

J亚型禽白血病病毒（ALV-J）在我国鸡群中普遍流行，造成的危害巨大。然而，抗ALV-J感染免疫应答机制一直都没有得到系统而深入的研究，尤其是ALV-J特异性CD4+T细胞免疫应答研究尚属空白。本项目拟在体外建立ALV-J全抗原特异性CD4+T细胞系，观察其对ALV-J单个病毒蛋白抗原应答的效应分子表达情况，阐明其在抗ALV-J感染免疫中的作用。采用步移重叠合成肽的方法，对ALV-J优势应答蛋白的优势表位进行筛选和鉴定，并在离体水平验证免疫优势应答谱。通过研究优势表位的MHC限制性，及ALV-J和表位特异性CD4+T细胞Th1和Th2类效应因子表型；揭示MHC-B单倍型SPF鸡对ALV-J抗性差异机制。本项目将明确ALV-J特异性CD4+T细胞免疫优势表位及表型，揭示ALV-J诱导鸡CD4+T细胞特异性应答反应机制，为建立有效的ALV-J防控技术和培育抗性品种提供数据和理论支持。

Avian Leukosis Subgroup J (ALV-J) is prevalent among various breeds of chickens in our country and causing huge harm. However, there is no thoroughly study on the mechanism of anti-ALV-J immune response. Especially, the study on ALV-J specific CD4+T cell immune response is still vacancy up to now. This project intends to establish the ALV-J antigen specific CD4+T cell line in vitro, then to observe their effector productions directing at ALV-J single antigen response, and to explore their potential effect in the anti-ALV-J infection immunity. Overlapping synthetic peptides will be used to identify the immunodominant epitopes of ALV-J immunodominant antigen. Then, the frequencies of epitope specific CD4+T cell would be verified in ex vivo. This project would elucidate the mechanism of the resistance difference among MHC-B haplotype restricted chicken lines to ALV-J, via analyzing the MHC restriction of immunodominant epitopes, and Th1 or Th2 phenotype of ALV-J and epitope specific CD4+ T cell. The research results would expound the immunodominant epitopes and phenotype of ALV-J specific CD4+ T cell response, and then uncover the mechanism of ALV-J-induced chicken CD4+T cell specific immune response. It would provide some data and theories support for making ALV-J control measures and breeding resistance varieties.