Decreased expression of Ii-derived p25 and P67/69 in hairy leukemic cells

• Published in: Leukemia research Vol. 12; no. 10; pp. 787 - 794
• Main Authors: XIAO-RUI YAO, HUMPHREYS, R. E
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Science 1988
• Subjects: Antigen-Presenting Cells - immunology; Antigen-Presenting Cells - metabolism; Antigens, Differentiation, B-Lymphocyte; Antigens, Neoplasm - biosynthesis; B-Lymphocytes - immunology; Biological and medical sciences; Burkitt Lymphoma - immunology; Cell Line; Hematologic and hematopoietic diseases; Histocompatibility Antigens Class II - biosynthesis; Histocompatibility Antigens Class II - immunology; Humans; Leukemia, Hairy Cell - immunology; Leukemia, Hairy Cell - pathology; Leukemias. Malignant lymphomas. Malignant reticulosis. Myelofibrosis; Medical sciences; Neoplasm Proteins - biosynthesis; Neoplasm Proteins - deficiency; Protein Processing, Post-Translational; Human; Proteins; Antigen presentation; Hairy cell leukemia; Immunological investigation; Class II histocompatibility antigen; Hemopathy; B-Lymphocyte; Tumor cell
• ISSN: 0145-2126; 1873-5835
• DOI: 10.1016/0145-2126(88)90030-6

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.