Avva R R, Cresswell P
Section of Immunobiology, Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, Connecticut 06510.
Immunity. 1994 Dec;1(9):763-74. doi: 10.1016/s1074-7613(94)80018-9.
HLA-DR molecules associated with class II-associated invariant chain peptides (CLIP) are generated in vivo as an intermediate in class II maturation. Such complexes can be produced in vitro by proteolytic digestion of DR alpha beta I complexes, suggesting that CLIP is a residual fragment that remains associated with class II molecules following I chain degradation. In vitro, CLIP dissociation from DR alpha beta dimers occurs at different rates depending on the allele, and is facilitated by low pH and by detergents containing 8-10 carbon unbranched hydrocarbons, or by primary aliphatic amines or carboxylic acids. The accumulation of DR alpha beta CLIP complexes in HLA-DM-negative antigen-processing mutant cells argues that a functionally similar mechanism, dependent on HLA-DM expression, catalyzes in vivo CLIP dissociation and generation of normal class II-peptide complexes.
与II类相关恒定链肽（CLIP）相关的HLA - DR分子在体内作为II类成熟过程中的中间体产生。这种复合物可以通过对DRαβI复合物进行蛋白水解消化在体外产生，这表明CLIP是I链降解后仍与II类分子相关的残留片段。在体外，CLIP从DRαβ二聚体上解离的速率因等位基因而异，并受到低pH值、含有8 - 10个碳的直链烃的去污剂、伯脂肪胺或羧酸的促进。HLA - DM阴性抗原加工突变细胞中DRαβCLIP复合物的积累表明，一种功能上类似的机制（依赖于HLA - DM表达）在体内催化CLIP解离并产生正常的II类 - 肽复合物。
