Characterization of human B lymphocyte specific antigens.

Anti-human B cell serum (ABS) was developed by sequentially absorbing a rabbit anti-human tonsil serum (AHTS) with human red cells, liver, serum, and thymocytes. AHTS was also absorbed quantitatively with tissues and cells from different sources. ABS was nontoxic for thymocytes but lysed the majority of chronic lymphocytic leukemia (CLL) cells. This also killed a number of tonsil and blood lymphocytes which bound erythrocyte-antibody-complement complexes but not sheep erythrocytes. In further studies, it was shown that phytohemagglutin-responsibility of peripheral blood lymphocytes was not affected by treating them with ABS and complement. Anti-B cell activity of AHTS was not changed by absorption with thymus, liver, kidney, and brain tissues but absorbed with tonsil and CLL cells. These data confirm the B cell specificity of ABS. Indirect immunofluorescence was carried out on tissue sections of human tonsils and lymph nodes, which indicated that ABS-reactive cells were concentrated in lymphoid follicles including germinal centers, while plasma cells and cells located in the thymus-dependent area were essentially devoid of immunofluorescence.