Related Experiment Videos
Immunoglobulin isotype switching in xid mice
K A Brorson1, M V Krasnokutsky, K E Stein
1Division of Monoclonal Antibodies, Food and Drug Administration, Bethesda, MD 20892, USA.
Mice with the x-linked immunodeficiency mutation (xid) are unresponsive to polysaccharide antigens, lack a subset of B cells, and have low serum IgM (2-20% of normal) and IgG3 (3% of normal). Because of the disproportionate reduction of IgG3, the ability of B cells from xid mice to switch to gamma 3 was examined. Switching was indirectly measured by comparing IgG3 production and C gamma 3 mRNA steady state levels of purified B cells activated to switch to IgG3 by LPS in bulk culture. Direct measurement of switching was achieved by enumerating on a percentage basis switched cells in a filter disk culture assay and by FACS analysis. In both bulk culture and the filter disk assay, switching to gamma 3 was equivalent between xid and non-xid B cells.
Mice with the x-linked immunodeficiency mutation (xid) are unresponsive to polysaccharide antigens, lack a subset of B cells, and have low serum IgM (2-20% of normal) and IgG3 (3% of normal). Because of the disproportionate reduction of IgG3, the ability of B cells from xid mice to switch to gamma 3 was examined. Switching was indirectly measured by comparing IgG3 production and C gamma 3 mRNA steady state levels of purified B cells activated to switch to IgG3 by LPS in bulk culture. Direct measurement of switching was achieved by enumerating on a percentage basis switched cells in a filter disk culture assay and by FACS analysis. In both bulk culture and the filter disk assay, switching to gamma 3 was equivalent between xid and non-xid B cells.