The Journal of Immunology, Vol 143, Issue 10 3303-3308, Copyright © 1989 by American Association of Immunologists

ARTICLES

The early B lineage antigen BP-1 and the transformation-associated antigen 6C3 are on the same molecule

Q Wu, GF Tidmarsh, PA Welch, JH Pierce, IL Weissman and MD Cooper
Division of Developmental and Clinical Immunology, University of Alabama, Birmingham 35294.

Biochemical similarities and cellular distribution patterns of the early B lineage-specific BP-1 alloantigen and the B lineage transformation-associated 6C3 Ag prompted this comparative study of the reactivities of the BP-1 and 6C3 mAb. Both Ag were found to be expressed on the same cells in normal tissues, and on the same cell lines when a large panel was analyzed. The Ag are both phosphorylated and have identical m.w., which may vary in different cell types because of differences in glycosylation. Immunoprecipitation of pre-B cell lysates with the BP-1 antibody removed the 6C3-reactive molecules and vice versa. However, the 6C3 antibody did not inhibit binding of the BP- 1 antibody to viable cells and, in fact, enhanced immunofluorescence staining was observed when both antibodies were added together. These results indicate that the BP-1 and 6C3 antibodies react with different epitopes on the same molecule that is expressed in relatively low levels on normal early B lineage cells, and in relatively high levels on most neoplastic pre-B cells, pre-B cells in long term bone marrow cultures and certain stromal cell lines.

This article has been cited by other articles:

				Q. Lin, I. Taniuchi, D. Kitamura, J. Wang, J. F. Kearney, T. Watanabe, and M. D. Cooper T and B Cell Development in BP-1/6C3/Aminopeptidase A-Deficient Mice J. Immunol., May 15, 1998; 160(10): 4681 - 4687. [Abstract] [Full Text] [PDF]