title: Interferon-gamma suppresses B cell stimulation factor (BSF-1) induction of class II MHC determinants on B cells.
abstract: The data presented in this manuscript extend our previous observations that recombinant interferon-gamma (reIFN-gamma) can suppress anti-immunoglobulin (anti-Ig)-stimulated B cell proliferation, and demonstrate that reIFN-gamma can also suppress B cell stimulation factor type 1 (BSF-1)-stimulated increases in expression of MHC class II molecules (Ia) on B cells. This suppression is most effective when relatively low concentrations of BSF-1 are employed, but is still very substantial even when optimal concentrations of BSF-1 were used. This suppression is also observed when size-separated small B cells which are devoid of detectable macrophages or NK cells are cultured with BSF-1 and reIFN-gamma, thus suggesting that IFN-gamma-mediated inhibition is a consequence of a direct effect on the B cells. Incubation of B cells with reIFN-gamma for 24 hr before their culture with BSF-1 did not prevent BSF-1-stimulated increases in sIa. This finding supports the contention that the effect of IFN-gamma is not mediated via the stimulation of "suppressor" influences in these cell cultures. The inhibition of B cell activation by IFN-gamma occurs within the first 3 hr after the onset of culture, as demonstrated by the inability of antibody to IFN-gamma to totally reverse the IFN-gamma-mediated suppressive effects on B cell proliferation if it is added later than 3 hr after the onset of culture. These results suggest a role for IFN-gamma in down-regulating the ability of B cells to function as antigen-presenting cells in non-cognate T cell-dependent responses.
mesh_terms: D000818:Animals; D000954:Antigens, Surface / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology*; D002469:Cell Separation; D006131:Growth Inhibitors; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D007371:Interferon-gamma / Q000494:pharmacology*; D015847:Interleukin-4; D008213:Lymphocyte Activation; D008222:Lymphokines / Q000037:antagonists & inhibitors*; D051379:Mice
chemical_list: D000954:Antigens, Surface; D006131:Growth Inhibitors; D000949:Histocompatibility Antigens Class II; D008222:Lymphokines; D015847:Interleukin-4; D007371:Interferon-gamma