Sanderson F, Thomas C, Neefjes J, Trowsdale J
Human Immunogenetics Laboratory, Imperial Cancer Research Fund, London, United Kingdom.
Immunity. 1996 Jan;4(1):87-96. doi: 10.1016/s1074-7613(00)80301-5.
The exchange of HLA class II-associated invariant chain peptides (CLIP) for cognate peptide is catalyzed by HLA-DM under acidic conditions in vitro by an unknown mechanism. Here, we show an association between HLA-DM and HLA-DR in vivo by coprecipitation of the two heterodimers. The association is favored at low pH and in the nonionic detergent digitonin. Most DM-DR complexes are isolated from dense subcellular fractions. Recovery of HLA-DM by the conformation-dependent DR3 monoclonal antibody 16.23 suggests an association with HLA-DR heterodimers beyond the stage at which CLIP is released. The additional N-linked glycan on mutant DR3 molecules isolated from the 10.24.6 cell line, which interferes with DM-enhanced CLIP release from DR3 in vitro, also affects the DM-DR interaction.
在体外酸性条件下，HLA - DM通过未知机制催化HLA II类相关恒定链肽（CLIP）与同源肽的交换。在此，我们通过两种异二聚体的共沉淀展示了体内HLA - DM与HLA - DR之间的关联。这种关联在低pH值和非离子去污剂洋地黄皂苷存在的情况下更易发生。大多数DM - DR复合物是从致密的亚细胞组分中分离出来的。依赖构象的DR3单克隆抗体16.23对HLA - DM的回收表明，在CLIP释放阶段之后，HLA - DM仍与HLA - DR异二聚体存在关联。从10.24.6细胞系分离出的突变DR3分子上额外的N - 连接聚糖，在体外会干扰DM增强的CLIP从DR3的释放，它也会影响DM - DR的相互作用。
