The activation antigen BLAST-2, when shed, is an autocrine BCGF for normal and transformed B cells.
A shed form of the membrane-bound B cell activation marker, BLAST-2 (Epstein-Barr virus cell surface, CD 23) was immune-affinity purified from Epstein-Barr virus-transformed lymphoblast conditioned medium. SDS-PAGE analysis revealed a complex of two polypeptides, mol. wts 25,000 and 12,000, here termed s-BLAST-2. We show that this complex, when purified to homogeneity, can act as a growth factor for EBV-infected B lymphoblasts and normal receptor-stimulated B cell blasts. It has no effect on resting B or T cells. These data suggest that the BLAST-2 antigen has a role in autocrine B cell growth. Additionally, this complex is a co-mitogen for PHA-stimulated murine thymocytes, a property of interleukin-1.
D000944:Antigens, Differentiation, B-Lymphocyte; D000954:Antigens, Surface / Q000276:immunology* / Q000302:isolation & purification; D001402:B-Lymphocytes / Q000276:immunology*; D002472:Cell Transformation, Viral; D002478:Cells, Cultured; D006133:Growth Substances / Q000276:immunology*; D004854:Herpesvirus 4, Human / Q000276:immunology*; D006801:Humans; D015847:Interleukin-4; D008213:Lymphocyte Activation; D008222:Lymphokines / Q000276:immunology*; D008970:Molecular Weight; D013329:Structure-Activity Relationship
D000944:Antigens, Differentiation, B-Lymphocyte; D000954:Antigens, Surface; D006133:Growth Substances; D008222:Lymphokines; D015847:Interleukin-4