The role of CD45RA on human B-cell function: anti-CD45RA antibody (anti-2H4) inhibits the activation of resting B cells and antibody production of activated B cells independently in humans.
Anti-CD45RA antibody defined by anti-2H4 monoclonal antibody has been reported to split CD4+T cells into two distinct subpopulations. CD45RA antigen is present on the surface of virtually more than 95% B lymphocytes in the purified tonsillar B-cell preparations. We examined the role of CD45RA antigen on human B-cell function using this antibody. The addition to anti-2H4 to tonsillar B cells inhibited the proliferative response induced by Staphylococcus aureus Cowan strain I(SAC) in a dose-dependent manner. Kinetic analysis indicated that anti-2H4 exerted its inhibitory effect when added within the first 24 h of culture initiation during a 72-h culture period. Anti-2H4 inhibited the transferrin receptor expression without interfering with the expression of the IL-2 receptor on SAC-stimulated B cells in a short-term culture. Anti-2H4 blocked the progress of SAC-stimulated B cells from the G1 to S phase of the cell cycle. These events suggested that anti-CD45RA MoAb inhibited the proliferative response by directly acting on B cells in the G1 phase. In addition, anti-CD45RA antibody also had a suppressive effect on early phase of B-cell differentiation. This effect appeared to be independent of its suppressive effect on proliferation, because anti-CD45RA did not inhibit the proliferative response of preactivated B cells with lymphokines. These studies suggested that the restricted epitope recognized by anti-2H4 antibody may be directly involved in regulatory function on B cells.
Morikawa
K
K
Department of Internal Medicine, Shimane Medical University, Japan.
Oseko
F
F
Morikawa
S
S
D000911:Antibodies, Monoclonal / Q000276:immunology*; D000917:Antibody Formation; D000918:Antibody Specificity; D015703:Antigens, CD / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology / Q000502:physiology*; D004247:DNA / Q000096:biosynthesis; D016193:G1 Phase; D006649:Histocompatibility Antigens / Q000276:immunology*; D006801:Humans; D007136:Immunoglobulins / Q000037:antagonists & inhibitors / Q000378:metabolism; D007700:Kinetics; D017493:Leukocyte Common Antigens; D008213:Lymphocyte Activation / Q000276:immunology*; D012313:RNA / Q000096:biosynthesis; D016196:S Phase; D013209:Staphylococcal Vaccines / Q000494:pharmacology; D013211:Staphylococcus aureus / Q000276:immunology; D013997:Time Factors
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D006649:Histocompatibility Antigens; D007136:Immunoglobulins; D013209:Staphylococcal Vaccines; D012313:RNA; D004247:DNA; D017493:Leukocyte Common Antigens