Sette A, Buus S, Colon S, Miles C, Grey H M
Department of Medicine, National Jewish Center for Immunology and Respiratory Medicine, Denver, CO.
J Immunol. 1989 Jan 1;142(1):35-40.
The Ia binding regions were analyzed for three unrelated peptide Ag (sperm whale myoglobin 106-118, influenza hemagglutinin 130-142, and lambda repressor protein 12-26) for which binding to more than one Ia molecule has previously been demonstrated. By determining the binding profile of three separate series of truncated synthetic peptides, it was found that in all three cases the different Ia reactivities mapped to largely overlapping regions of the peptides; although, for two of the peptides, the regions involved in binding the different Ia specificities were distinct. Moreover, subtle differences were found to dramatically influence some, but not other, Ia reactivities. Using a large panel of synthetic peptides it was found that a significant correlation exists between the capacity of peptides to interact with different alleles of the same molecule (i.e., IAd and IAk), but no correlation was found with the capacity of peptides to interact with different isotypes within the same haplotype (i.e., IAd and IEd). These data suggest that different alleles of the same MHC molecule may actually recognize closely related structures, whereas different isotypes may recognize unrelated, albeit non-mutually exclusive, structures on an Ag molecule.
对三种不相关的肽抗原（抹香鲸肌红蛋白106 - 118、流感血凝素130 - 142和λ阻遏蛋白12 - 26）的Ia结合区域进行了分析，此前已证明这些抗原可与多种Ia分子结合。通过确定三个独立系列的截短合成肽的结合谱，发现所有三种情况下，不同的Ia反应性映射到肽的大部分重叠区域；不过，对于其中两种肽，参与结合不同Ia特异性的区域是不同的。此外，还发现细微差异会显著影响某些而非其他的Ia反应性。使用大量合成肽发现，肽与同一分子的不同等位基因（即IAd和IAk）相互作用的能力之间存在显著相关性，但与肽与同一单倍型内不同同种型（即IAd和IEd）相互作用的能力之间未发现相关性。这些数据表明，同一MHC分子的不同等位基因实际上可能识别密切相关的结构，而不同同种型可能识别抗原分子上不相关但并非相互排斥的结构。
