Mendoza L M, Paz P, Zuberi A, Christianson G, Roopenian D, Shastri N
Department of Molecular and Cell Biology, University of California, Berkeley 94720, USA.
Immunity. 1997 Oct;7(4):461-72. doi: 10.1016/s1074-7613(00)80368-4.
The products of minor histocompatibility (H) loci are serious barriers to tissue transplantation even among major histocompatibility complex (MHC) identical individuals, frequently causing chronic graft rejection and graft versus host disease. Over 50 minor H loci map to mouse autosomal chromosomes but none are known at the molecular level. By expression cloning, we identified the H13 locus, a classical minor H locus first detected 30 years ago by the trait of graft rejection. The H13a allele is located on chromosome 2 and encodes a novel protein that yields the rare naturally processed nonapeptide SSVVGVWYL (SVL9) for presentation by the Db MHC class I molecule. The SVL9 peptide binds Db MHC despite the absence of the consensus binding motif, and a conservative methyl group substitution (Valine 4 <--> Isoleucine) explains why reciprocal T cell responses are elicited in H13a and H13b congenic strains.
即使在主要组织相容性复合体（MHC）相同的个体之间，次要组织相容性（H）位点的产物也是组织移植的严重障碍，常常导致慢性移植排斥和移植物抗宿主病。超过50个次要H位点定位于小鼠常染色体，但在分子水平上均不为人所知。通过表达克隆，我们鉴定出了H13位点，这是一个经典的次要H位点，30年前首次通过移植排斥特性检测到。H13a等位基因位于2号染色体上，编码一种新型蛋白质，该蛋白质产生罕见的天然加工九肽SSVVGVWYL（SVL9），以供Db MHC I类分子呈递。尽管缺乏共有结合基序，SVL9肽仍能结合Db MHC，保守的甲基取代（缬氨酸4 <--> 异亮氨酸）解释了为什么在H13a和H13b同源系中会引发相互的T细胞反应。
