Pieters J
Basel Institute for Immunology, Grenzacherstrasse 487, Postfach CH-4005 Basel, Switzerland.
Curr Opin Immunol. 1997 Feb;9(1):89-96. doi: 10.1016/s0952-7915(97)80164-1.
Presentation of antigenic peptides by MHC class II molecules to CD4(+) T cells requires many events in both the biosynthetic and endocytic pathways that must all occur in a controlled and coordinated fashion. In recent years the roles of two important chaperones, the invariant chain and the HLA-DM dimer, in promoting the acquisition of peptides by MHC class II molecules have largely been elucidated. The different compartments within the endosomal/lysosomal pathway that are involved in peptide loading are now being characterized. In addition to the specialized MHC class II compartments that exist in antigen-presenting cells, other intracellular compartments may also be involved in peptide loading. The precise mechanisms and intracellular sites of MHC class II peptide loading appear to dictate the nature of the T-cell epitopes presented by the antigen-presenting cell.
MHC II类分子将抗原肽呈递给CD4(+) T细胞需要生物合成途径和内吞途径中的许多事件，这些事件都必须以可控且协调的方式发生。近年来，两种重要的伴侣蛋白——恒定链和HLA-DM二聚体，在促进MHC II类分子获取肽段方面的作用已基本阐明。参与肽段装载的内体/溶酶体途径中的不同区室目前正在被表征。除了抗原呈递细胞中存在的专门的MHC II类区室外，其他细胞内区室也可能参与肽段装载。MHC II类分子肽段装载的精确机制和细胞内位点似乎决定了抗原呈递细胞所呈递的T细胞表位的性质。
