Eastman S, Deftos M, DeRoos P C, Hsu D H, Teyton L, Braunstein N S, Hackett C J, Rudensky A
Howard Hughes Medical Institute, University of Washington School of Medicine, Seattle 98195, USA.
Eur J Immunol. 1996 Feb;26(2):385-93. doi: 10.1002/eji.1830260218.
Complexes of major histocompatibility complex (MHC) class II molecules containing invariant chain (Ii)-derived peptides, known as class II-associated invariant chain peptides (CLIP), are expressed at high levels in presentation-deficient mutant cells. Expression of these complexes in mutant and wild-type antigen-presenting cells suggests that they represent an essential intermediate in the MHC class II antigen-presenting pathway. We have generated a monoclonal antibody, 30-2, which is specific for these complexes. Using this antibody, we have found quantitative differences in CLIP:MHC class II surface expression in mutant and wild-type cells. Our experiments also show that CLIP:MHC class II complexes are preferentially expressed on the cell surface similar to total mature MHC class II molecules. These complexes are found to accumulate in the endosomal compartment in the process of endosomal Ii degradation. Analysis of the fine specificity of the antibody indicates that these complexes have Li peptide bound to the peptide-binding groove.
含有恒定链（Ii）衍生肽的主要组织相容性复合体（MHC）II类分子复合物，即II类相关恒定链肽（CLIP），在呈递缺陷型突变细胞中高水平表达。这些复合物在突变型和野生型抗原呈递细胞中的表达表明，它们代表MHC II类抗原呈递途径中的一个重要中间体。我们制备了一种针对这些复合物的单克隆抗体30-2。使用该抗体，我们发现突变型和野生型细胞中CLIP:MHC II类分子表面表达存在定量差异。我们的实验还表明，CLIP:MHC II类复合物与总成熟MHC II类分子相似，优先在细胞表面表达。发现这些复合物在内体Ii降解过程中在内体区室中积累。对该抗体精细特异性的分析表明，这些复合物的肽结合槽中结合有Ii肽。
