Pre－S_（2）蛋白T细胞识别的精细特异性

本文采用合成交叠肽扫描的方法在６种不同Ｈ－２单倍型小鼠确定了ｄ／ｙ二种亚型Ｐｒｅ－Ｓ＿（２）蛋白的Ｔ细胞识别部位。发现：（１）在所观察的６种同类系小鼠均存在对Ｐｒｅ－Ｓ＿（２）蛋白反应的亚型特异性，这可能与Ｐｒｅ－Ｓ＿（２）蛋白分子Ｃ末端的多态性有关；（２）Ｐｒｅ－Ｓ＿（２）蛋白的Ｔ细胞识别部位在５种同类系小鼠位于Ｃ末端３２个氨基酸残基顺序内，在另一种同类系小鼠则位于Ｎ末端顺序，这与我们先前的理论观测结果相一致；（３）进一步分析发现：不同Ｈ２单倍型小鼠对Ｐｒｅ－Ｓ＿（２）蛋白的Ｔ细胞识别是ＭＨＣ分子依赖的；（４）２４－５５肽段的圆二色性表明该肽段内存在一个α－螺旋，可能是其作为Ｔ细胞识别部位的结构基础。以上结果对于设计新一代乙型肝炎疫苗有意义。

The Fine Specificity of Murine T cell Recognition ofPre-S_(2)Region of HBsAg

The fine specificity of murine T cell recognition of the pre-S_(2)region were studide to examine the influ-ence of viral subtype and to identify specific T cell recognition sites in a panel of H-2 congenic strains.Immunization withPre-S_(2) contaning HBsAg particles of the adw_2and ayw subtypes indicated that T cell recognition of the Pre-S_(2)region is predominantiy subtype specific in murine strains of different six H-2 haplotypes.Furthermore.studies using overlapping synthetic peptidesillustrated that the C-terminal sequence of the Pre-S_(2) region is the dominant focus of T cell recognition in 5 murine strains The fine specificity of T cell recognition to the Pre-S_(2) region Lastly,it was the responding strain; T cell recognition of the C-terminal half was subtype specific, which is consistent with the fact thatthe C-terminal sequence is highly polymorphic between the d and the y subtypes of the Pre-S_(2) region. Lastly.it was shown that the ability of P14-55 to elicit T cells corss reactive with the native Pre-S_(2) region is poor. Those findings sug-gested that both subtypes should be increase the frequency of T cell response to the Pre-S_(2) region. and to ensure Th cell memory relavant to infection with HBV of either the d or the y subtype in the development of new vac-cines.The CD experiments were carried out on a Jasco-J500 model,and the CD spectra suggested that P23-55 contains ana-hilix which might be the structure basis of T cell recognition.