Teyton L
Laboratoire d'Immunogénétique Moléculaire, CJF INSERM, Paris, France.
Nouv Rev Fr Hematol (1978). 1994;36 Suppl 1:S33-6.
The transport of MHC molecules is largely determined by the completion of their folding. This critical step is dependent upon the acquisition of immunogenic peptides able to stabilize the structure of the terminal part of the molecule which is exposed to the T cell receptor. The association with chaperone-like molecules allows the loading to take place in specific compartments: ER for MHC class I molecules, and endocytotic pathway for MHC class II molecules. Different affinities for different chaperone molecules split antigen presentation into two different pathways: endogenous (for MHC class I molecules), and exogenous (for MHC class II molecules). The MHC class II chaperone molecule is the invariant chain. This polypeptide regulates the transport of MHC class II molecules towards the endosomal pathway. It also governs the accessibility of the peptide binding groove of MHC class II molecules.
MHC分子的转运很大程度上取决于其折叠的完成。这一关键步骤依赖于获取能够稳定分子末端结构（该结构暴露于T细胞受体）的免疫原性肽段。与伴侣样分子的结合使得加载过程能够在特定的区室中发生：MHC I类分子在内质网，MHC II类分子在内吞途径。对不同伴侣分子的不同亲和力将抗原呈递分为两种不同的途径：内源性途径（针对MHC I类分子）和外源性途径（针对MHC II类分子）。MHC II类伴侣分子是恒定链。这种多肽调节MHC II类分子向内体途径的转运。它还控制MHC II类分子肽结合槽的可及性。
