title: Endocytosis of class II histocompatibility antigens and formation of intracytoplasmic granules at the final differentiation stage of human B lymphocytes.
abstract: The expression of histocompatibility antigens was investigated using several human lymphoid cell lines representative of different maturation stages of the B-cell lineage. Class II HLA antigens were found at the surface of all cell lines. However, in the myeloma cell line U266, an intracellular macrovesicular pool of these antigens was found in some cells. It originated from microvesicular endocytosis of the surface antigen, subsequently leading to cells bearing HLA class I but not class II antigens. Since the latter play a major role in cellular interactions regulating B-cell differentiation, this phenomenon may be linked to the final stage of maturation of B lymphocytes into plasma cells.
mesh_terms: D000954:Antigens, Surface; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology*; D002454:Cell Differentiation; D002460:Cell Line; D003594:Cytoplasmic Granules / Q000276:immunology*; D004705:Endocytosis; D006680:HLA Antigens; D006801:Humans
chemical_list: D000954:Antigens, Surface; D006680:HLA Antigens