Lang T, Antoine J C
Département de Biologie Moléculaire, Institut Pasteur, Paris, France.
Immunology. 1991 Feb;72(2):199-205.
The localization of MHC class II molecules (Ia) was studied by ultrastructural immunocytochemistry in murine bone marrow-derived macrophages stimulated by recombinant interferon-gamma (rIFN-gamma). Ia molecules were detected on the plasma membrane and on the limiting membrane and internal structures of vesicular acidic compartments. Some of these vesicules also contained cathepsin B and/or cathepsin D. The use of BSA-gold, a marker of fluid phase endocytosis, allowed the identification of Ia-positive organelles as endocytic compartments. The first to be labelled with BSA-gold also contained the cation-independent mannose 6-phosphate receptor (MPR) but not the 120,000 molecular weights lysosomal glycoprotein (lgp 120). Later on, BSA-gold appeared in Ia+, MPR+, lgp 120+ compartments. Collectively these data suggest that intracellular Ia molecules are mainly present in early and late endosomes.
采用超微结构免疫细胞化学方法，研究了重组γ干扰素（rIFN-γ）刺激的小鼠骨髓来源巨噬细胞中II类主要组织相容性复合体分子（Ia）的定位。在质膜以及囊泡酸性区室的界膜和内部结构上检测到了Ia分子。其中一些囊泡还含有组织蛋白酶B和/或组织蛋白酶D。利用牛血清白蛋白-金（BSA-金），一种液相内吞作用的标志物，可将Ia阳性细胞器鉴定为内吞区室。最先被BSA-金标记的细胞器也含有不依赖阳离子的甘露糖6-磷酸受体（MPR），但不含有120,000分子量的溶酶体糖蛋白（lgp 120）。随后，BSA-金出现在Ia+、MPR+、lgp 120+区室中。这些数据共同表明，细胞内Ia分子主要存在于早期和晚期内体中。
