Perkins D L, Berriz G, Wang Y S, Smith J A, Gefter M L
Laboratory of Immunogenetics and Transplantation, Brigham and Women's Hospital, Boston, MA.
Eur J Immunol. 1991 Nov;21(11):2781-9. doi: 10.1002/eji.1830211120.
There is structural and functional evidence that both class I- and II-restricted T cells recognize short processed peptides bound to MHC molecules. Although the structural conformation of bound peptides remains unknown, no evidence of distinct structural motifs of class I- or class II-restricted peptides has been described. Conversely, two algorithms proposed to predict T cell epitopes, and based on primary amino acid sequence or tertiary structure, are both compatible with many observed class I- and class II-restricted peptides. We previously identified eight class I-restricted peptides which were also recognized by class II-restricted T cells. Based on functional and direct binding studies, additional examples of peptides with both class I and II restrictions have been identified. In this study, we have directly compared the fine specificity of T cell recognition of a single epitope in a single mouse strain in the context of both class I- and class II-restricted responses. Based on a panel of analogue peptides with amino acid substitutions and peptides of various lengths, we observed several striking similarities in the recognition patterns of both class I- and class II-restricted T cells. In addition, some characteristics of recognition were different in the two systems indicating that the recognition processes were similar but not identical.
有结构和功能方面的证据表明，I类和II类限制性T细胞都能识别与MHC分子结合的短加工肽段。尽管结合肽段的结构构象尚不清楚，但尚未有关于I类或II类限制性肽段独特结构基序的证据被描述。相反，两种基于一级氨基酸序列或三级结构提出的预测T细胞表位的算法，都与许多观察到的I类和II类限制性肽段兼容。我们之前鉴定出了8种I类限制性肽段，它们也能被II类限制性T细胞识别。基于功能和直接结合研究，已经鉴定出了更多具有I类和II类双重限制性的肽段实例。在本研究中，我们在I类和II类限制性反应的背景下，直接比较了单个小鼠品系中单个表位的T细胞识别精细特异性。基于一组具有氨基酸替代的类似肽段和不同长度的肽段，我们观察到I类和II类限制性T细胞的识别模式有几个显著的相似之处。此外，两个系统中的一些识别特征有所不同，这表明识别过程相似但并不完全相同。
