IFN-gamma enhances secretion of IgG2a from IgG2a-committed LPS-stimulated murine B cells: implications for the role of IFN-gamma in class switching.
IFN-gamma is a pleiotropic lymphokine that influences the isotypes of immunoglobulin secreted by B cells. IFN-gamma inhibits the secretion of IgG3, IgG2b, IgG1, and IgE, and enhances the secretion of IgG2a. We have examined the mechanism of IFN-gamma-mediated enhancement of IgG2a secretion in sorted populations of B cells and find that IFN-gamma reproducibly stimulates a twofold increase in the precursor frequency of IgG2a-secreting cells in the sIgG2a+ population. Additionally, we find that IFN-gamma does not induce an increase in the clone size of IgG2a-secreting cells. IFN-gamma stimulates a twofold increase in the precursor frequency of IgG2a-secreting cells from sIgG- and unsorted B cells which can be attributed to an increase in IgG2a secretion from IgG2a-committed cells in these populations. Hence, under the culture conditions utilized in these studies. IFN-gamma enhances IgG2a secretion from IgG2a-committed cells and does not induce a class switch.
Bossie
A
A
Department of Microbiology, University of Texas Southwestern Medical Center, Dallas.
Vitetta
E S
ES
D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D002478:Cells, Cultured; D003429:Cross Reactions; D005260:Female; D006041:Goats; D007074:Immunoglobulin G / Q000276:immunology / Q000378:metabolism*; D007132:Immunoglobulin Isotypes / Q000378:metabolism*; D007371:Interferon-gamma / Q000494:pharmacology*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D051379:Mice; D008807:Mice, Inbred BALB C
D007074:Immunoglobulin G; D007132:Immunoglobulin Isotypes; D008070:Lipopolysaccharides; D007371:Interferon-gamma