Ceppellini R, Frumento G, Ferrara G B, Tosi R, Chersi A, Pernis B
Istituto Nazionale per la Ricerca sul Cancro, Genova, Italy.
Nature. 1989 Jun 1;339(6223):392-4. doi: 10.1038/339392a0.
T cells recognize protein antigens as fragments (peptides) held in a defined binding site of class I or class II major histocompatibility (MHC) molecules. The formation of complexes between various immunologically active peptides and different MHC molecules has been demonstrated directly in binding studies between the peptides and solubilized, purified molecules of class II MHC. Studies with intact cells, living or fixed, have not directly demonstrated the binding of the peptides to MHC molecules on antigen-presenting cells, but the formation of such complexes has been shown indirectly through the capacity of antigen-presenting cells to stimulate specific T cells. Here we report evidence that supports directly the binding of radiolabelled influenza matrix peptide 17-29 to products of the human class II MHC locus HLA-DR, on living homozygous B-cell lines, and we show that the kinetics of such binding is much faster with living cells than with fixed cells. Furthermore, whereas the peptide reacts with HLA-DR molecules of all alleles, it binds preferentially to DR1, the restricting element in antigen presentation.
T细胞将蛋白质抗原识别为结合在I类或II类主要组织相容性（MHC）分子特定结合位点上的片段（肽段）。各种具有免疫活性的肽段与不同MHC分子之间复合物的形成，已在肽段与可溶解、纯化的II类MHC分子的结合研究中得到直接证明。使用完整细胞（活细胞或固定细胞）进行的研究，尚未直接证明肽段与抗原呈递细胞上的MHC分子的结合，但通过抗原呈递细胞刺激特异性T细胞的能力，已间接表明了此类复合物的形成。在此，我们报告了支持放射性标记的流感病毒基质肽17 - 29与人类II类MHC基因座HLA - DR产物在活的纯合B细胞系上直接结合的证据，并且我们表明这种结合在活细胞中的动力学比在固定细胞中快得多。此外，虽然该肽段与所有等位基因的HLA - DR分子都发生反应，但它优先结合DR1，即抗原呈递中的限制元件。
