Differential effect of anti-HLA class I monoclonal antibodies on resting and in vivo-induced B lymphocytes.
The role of HLA class I antigens in B cell triggering was investigated by analyzing the effect of monoclonal antibodies (MAbs) directed to such molecules on the in vitro function of resting and in vivo-induced lymphoblastoid (LB) B cells. Staphylococcus aureus Cowan I (SAC)-induced proliferation of high-density B lymphocytes was markedly inhibited by W6/32 MAb (reactive with a monomorphic determinant contributed by an alpha-chain and beta 2-microglobulin) but not by FG2/2 MAb (reactive with beta 2-microglobulin). The inhibition was not due to either a toxic effect or a change in the response kinetics. In contrast, LB B cells' spontaneous DNA synthesis and IgG production was not altered by such MAb, although these cells possessed surface HLA class I antigens. These findings suggest that HLA class I molecules are involved in the activation process of resting but not mature B lymphocytes.
de la Sen
M L
ML
Servicio de Immunologia, Hospital Ramon y Cajal, Madrid, Spain.
Brieva
J A
JA
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology*; D002478:Cells, Cultured; D004247:DNA / Q000096:biosynthesis; D006680:HLA Antigens / Q000276:immunology*; D007136:Immunoglobulins / Q000378:metabolism; D008213:Lymphocyte Activation; D051379:Mice
D000911:Antibodies, Monoclonal; D006680:HLA Antigens; D007136:Immunoglobulins; D004247:DNA