Evidence for an association between CD23 and the receptor for a low molecular weight B cell growth factor.
Low molecular weight B cell growth factor (BCGF) and a monoclonal antibody (MHM6) to the 45-kDa, B lineage-restricted, CD23 activation antigen (BLAST-2; EBVCS) were found to be indistinguishable in their biological effects. Individually, both augmented DNA synthesis in activated, but not resting, B lymphocytes while no additional enhancement resulted from using the two agonists in combination. Furthermore, by increasing the expression of Tac, both MHM6 and BCGF promoted activated B cells to respond more vigorously to the late addition of recombinant interleukin 2. The presence of BCGF during B cell activations was found to down-regulate the expression of the CD23 antigen while the coating of activated cells with MHM6 antibody diminished their capacity to absorb BCGF activity. The findings demonstrate that CD23 and a low molecular weight BCGF deliver a comparable growth-promoting signal to activated B cells. A possible relationship between CD23 and the receptor for the low molecular weight BCGF is discussed.
D000911:Antibodies, Monoclonal / Q000276:immunology; D000954:Antigens, Surface / Q000032:analysis; D001402:B-Lymphocytes / Q000187:drug effects; D002453:Cell Cycle; D006133:Growth Substances / Q000378:metabolism / Q000494:pharmacology*; D006801:Humans; D007376:Interleukin-2; D015847:Interleukin-4; D008213:Lymphocyte Activation; D008222:Lymphokines / Q000378:metabolism / Q000494:pharmacology*; D008970:Molecular Weight; D011971:Receptors, Immunologic / Q000032:analysis; D015375:Receptors, Interleukin-2; D019948:Receptors, Interleukin-4; D011975:Receptors, Mitogen / Q000032:analysis / Q000187:drug effects* / Q000276:immunology; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7
D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D006133:Growth Substances; D007376:Interleukin-2; D008222:Lymphokines; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2; D019948:Receptors, Interleukin-4; D011975:Receptors, Mitogen; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7; D015847:Interleukin-4