Expression of membrane-bound burst-promoting activity is mediated by allogeneic effector cells.
To investigate whether "self" and "non-self" recognition processes are involved in murine erythropoiesis, the expression of membrane-bound burst-promoting activity (mBPA) was determined for B lymphocytes purified from spleens of CF-1, C57 BL/6J, B6021-7115, and CAF-1J mice using syngeneic and allogeneic bone marrow cultures. Addition of B lymphocyte conditioned medium (LCM), shed membrane-derived vesicles, or intact plasma membranes prepared from syngeneic murine cells stimulated erythroid burst-forming unit (BFU-E) proliferation by two- to three-fold above control levels. BFU-E proliferation was increased by six- to eight-fold, however, when LCM, shed membrane vesicles, or plasma membranes purified from allogenic B lymphocytes were used as sources of growth-stimulatory activity. Bioactivity was immunoprecipitated from detergent extracts of membranes purified from both allogeneic and syngeneic lymphocytes with a monoclonal antibody that specifically recognizes mBPA, suggesting that the factors expressed by these cells share antigenic determinants. The results indicate that allogeneic effector cells are a more potent source of mBPA-like molecules than are syngeneic cells, suggesting that immune mechanisms may be involved in inducing erythroid growth factor expression at the B cell surface.
Guha
A
A
Connecticut Cancer Institute, University of Connecticut Health Center, Farmington 06032.
Tuck
D
D
Sorba
S
S
Dainiak
N
N
D000818:Animals; D000911:Antibodies, Monoclonal; D001402:B-Lymphocytes / Q000378:metabolism* / Q000648:ultrastructure; D001854:Bone Marrow Cells; D002455:Cell Division; D002462:Cell Membrane / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D002478:Cells, Cultured; D017077:Culture Media, Conditioned; D015672:Erythroid Precursor Cells / Q000166:cytology*; D004920:Erythropoiesis; D005260:Female; D016298:Hematopoietic Cell Growth Factors / Q000378:metabolism* / Q000494:pharmacology; D007074:Immunoglobulin G; D007163:Immunosorbent Techniques; D051379:Mice; D008810:Mice, Inbred C57BL; D013154:Spleen / Q000166:cytology
D000911:Antibodies, Monoclonal; D017077:Culture Media, Conditioned; D016298:Hematopoietic Cell Growth Factors; D007074:Immunoglobulin G