Morkowski S, Raposo G, Geuze H J, Rudensky A Y
Howard Hughes Medical Institute, University of Washington School of Medicine, Seattle, Wash., USA.
J Biomed Sci. 1999 Jan;6(1):53-63. doi: 10.1007/BF02256424.
In a combination of biochemical and immunoelectron-microscopical approaches we studied intracellular trafficking and localization of the endoplasmic-reticulum (ER)-formed complexes of murine MHC class II molecule I-Ab and an antigenic peptide Ealpha52-68 covalently linked to its beta-chain. The association with the peptide in the ER leads to sharp acceleration of the intracellular trafficking of the complexes to the plasma membrane. Within the cells, Ealpha52-68:I-Ab complexes accumulate in the multivesicular MHC class II compartment (MIIC), but not in denser multilaminar or intermediate type MIICs. The changes in the trafficking of ER-formed complexes result solely from the presence of the tethered peptide, since wild-type class II molecules traffic similarly in bare lymphocyte syndrome cells and in wild-type antigen-presenting cells.
我们采用生物化学与免疫电子显微镜相结合的方法，研究了内质网（ER）形成的小鼠MHC II类分子I-Ab与共价连接在其β链上的抗原肽Ealpha52-68复合物的细胞内运输和定位。在内质网中与肽的结合导致复合物向质膜的细胞内运输急剧加速。在细胞内，Ealpha52-68:I-Ab复合物积聚在多囊泡MHC II类区室（MIIC）中，但不在更致密的多层或中间型MIIC中积聚。内质网形成的复合物运输的变化仅源于连接肽的存在，因为野生型II类分子在裸淋巴细胞综合征细胞和野生型抗原呈递细胞中的运输方式相似。
