title: RAB-1: a new monoclonal antibody to leukemic hairy cells.
abstract: RAB-1, a new monoclonal antibody (McAb) to human leukemic hairy cell (HC) was produced. Using indirect immunofluorescence methods and microscopic or flow cytometric analysis, it was found that the RAB-1 antigen was expressed on few resting B cells and not on resting T lymphocytes, platelets, monocytes, erythroid and myeloid cells. RAB-1 expression on malignant cells was as follows: strongly positive in 15/15 hairy cell leukemia (HCL), negative with non-T and T-acute lymphoblastic leukemia and T-chronic lymphocytic leukemia (CLL); weakly expressed on myeloma and Waldenstrom cells; moderately on 10-25% of the cells in 4/10 B-CLL and 6/10 B lymphomas and in 7/7 B-prolymphocytic leukemia (PLL). Amongst human cell lines that were tested, RAB-1 reacted strongly with one HC line, moderately with the EBV-lymphoblastoid Daudi and Raji Burkitt's lines and was not expressed on Ramos, ALL, myeloid and erythroid cell lines. Normal B cells activated with PWM or anti-mu beads, and malignant B cells activated with anti-mu and TPA did not show an increase of expression of RAB-1 antigen. Interestingly, 30-40% of T4-Class II antigen positive cloned cells and T cells activated with PHA and Con.A expressed RAB-1, suggesting that this McAb recognizes surface molecule, newly induced during T-cell activation and constitutively expressed on HC and some B-cell malignancies.
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology*; D000918:Antibody Specificity; D000951:Antigens, Neoplasm / Q000276:immunology*; D000954:Antigens, Surface / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology; D002454:Cell Differentiation; D002460:Cell Line; D002462:Cell Membrane / Q000276:immunology; D005455:Fluorescent Antibody Technique; D006801:Humans; D007163:Immunosorbent Techniques; D007943:Leukemia, Hairy Cell / Q000276:immunology*; D008213:Lymphocyte Activation; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm; D000954:Antigens, Surface