Decreased expression of Ii-derived p25 and of P67/69 in hairy leukemic cells.
Hairy leukemic cells had altered expressions of accessory proteins (Ii, Ip, p70, p25) which associated intracellularly with class II MHC molecules. Immunoprecipitates from [35S]methionine, pulse-chase labeled leukemic cells, B-lymphoblastoid cells, and Burkitt's lymphoma cells were examined after 2-dimensional, polyacrylamide gel electrophoresis. The class II MHC-associated Ii chain was present in all three cell types, but the Ii-derived p25 protein was not found in HCL cells. Ip, the sialic acid-derivatized form of Ii, was well expressed in BLCL and Raji cells, but weakly in HCL cells. P70 was strongly expressed in BLCL and Raji cells, but negligibly in HCL cells. These alterations might reflect deficient mechanisms for antigen processing and presentation by these leukemic cells.
Yao
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Department of Pharmacology, University of Massachusetts Medical School, Worcester 01655.
Humphreys
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D000938:Antigen-Presenting Cells / Q000276:immunology / Q000378:metabolism*; D000944:Antigens, Differentiation, B-Lymphocyte; D000951:Antigens, Neoplasm / Q000096:biosynthesis*; D001402:B-Lymphocytes / Q000276:immunology; D002051:Burkitt Lymphoma / Q000276:immunology; D002460:Cell Line; D000090266:Chromobox Protein Homolog 5; D000949:Histocompatibility Antigens Class II / Q000096:biosynthesis / Q000276:immunology*; D006801:Humans; D007943:Leukemia, Hairy Cell / Q000276:immunology* / Q000473:pathology; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000172:deficiency*; D011499:Protein Processing, Post-Translational
D000944:Antigens, Differentiation, B-Lymphocyte; D000951:Antigens, Neoplasm; C000715594:CBX5 protein, human; D000949:Histocompatibility Antigens Class II; D009363:Neoplasm Proteins; C045084:invariant chain; D000090266:Chromobox Protein Homolog 5