IFN-GAMMA STIMULATES IGG(2) PRODUCTION FROM BOVINE B-CELLS COSTIMULATED WITH ANTI-MU AND MITOGEN

The effect of interferon-gamma (IFN-gamma) antibody production by anti-p or pokeweed mitogen-stimulated bovine B cells was studied. IFN-gamma induced IgG(2) secretion in isolated bulk B cell populations and in B cells sorted for IgM expression. IgM production was suppressed by the presence of IFN-gamma alone but this effect was antagonized by interleukin 2 (IL2). The effects of IFN-gamma on secreted levels of IgM, IgG(1), and IgC(2) correlated with the frequencies of cells expressing transcripts of the respective isotypes when stimulated with IFN-gamma-containing T cell supernatants. These results indicate that IFN-gamma plays a key role in IgG(2) production in the bovine by directly affecting suitably stimulated B cells. The ability of IL2 to synergize with IFN-gamma to augment both the IgM and IgG(2) responses implicates a T(H)1-like subset in regulation of this isotype. (C) 1994 Academic Press, Inc.