Surface immunoglobulins of lipopolysaccharide-stimulated spleen cells. The behavior of IgM, IgD and IgG.

The nature of Ig receptors carried by lipopolysaccharide (LPS)-stimulated mouse spleen B cells was analyzed by surface iodination, direct antiserum precipitation and polyacrylamide gel electrophoresis. LPS activation led to a rapid decrease of surface IgD to 20 % and 80 % of the original level on days three and five of culture, respectively. Efficiency of iodination of cells doubled after culture but the proportional radioactivity in IgM reace of cells, but only in small amounts (1 % of total surface Ig) and this expression of IgG remained constant during 5 days of culture. We could definitively identify gamma-chains on the surface of cells, but only in small amounts (1% of total surface Ig) and this expression of IgG remained constant during 5 days of culture.