滤泡辅助性T细胞(Tfh)是辅助体液免疫的一种新型CD4 T细胞亚群,可刺激B细胞增殖、分化 ,并在抗体亲和力成熟、高频突变、类别转换以及记忆性B细胞形成等过程中发挥了重要作用。目前几乎所有的人类疫苗都是基于保护T细胞依赖性的抗体反应,因此正确理解Tfh细胞的功能对于合理设计疫苗具有重要意义,为近年来免疫及疫苗学研究的热点。基于目前对其在HIV感染中的作用模式和机制尚不完全明了,本项目将通过多色流式细胞分析和分选技术, 系统地对不同强度中和抗体谱和产生中和抗体时间长短不同的HIV-1感染者Tfh和B细胞亚群的数量、表型和功能的差异进行研究，同时对B细胞产生中和抗体尤其是广谱中和抗体有决定性作用的Tfh细胞亚群，细胞因子和细胞通路进行检测。这些数据将为艾滋病疫苗和抗病毒免疫调节制剂的研制提供科学依据。

T follicular helper (Tfh) cells are new CD4 T cell subset specialized for providing help to B cells. They are selectively provide help to high-affinity B cells and promote their survival and differentiation into memory cells and plasma cells. Recently, nearly all the human vaccines are based on the protective T cell mediated antibody response, understanding function of Tfh is important to the vaccine design and becoming the focus of the immunology and vaccine research. As the function and anti-virus mechanism of Tfh in HIV infection is not clear, we intend to systemically analyze Tfh and B cell frequency, phenotype and function in HIV infected patients with different neutralizing antibody spectrum and neutralizing antibody producing time. Meanwhile, Tfh cell subsets, cytokines and cell pathways which is critical to neutralizing antibody production were also evaluated to understanding HIV pathogenesis and regulation mechanism, facilitating anti-virus drugs development and vaccine evaluation.