Surface Ig isotypes on cells responding to lipopolysaccharide by IgM and IgG secretion
Gronowicz, E.S.; Doss, C.; Assisi, F.; Vitetta, E.S.; Coffman, R.L.; Strober, S.
Journal of Immunology 123(5): 2049-2056
1979
ISSN/ISBN: 0022-1767 PMID: 385776 Document Number: 144852
Using the fluorescence-activated cell sorter (FACS), we have investigated the Ig isotypes present on murine B cells, which can be polyclonally activated by lipopolysaccharide (LPS) in low cell density cultures. The LPS response was partly inhibited as a result of staining with anti-IgD and anti-IgM reagents, but not with anti-IgG reagents. The IgM+, IgD+, or IgG- fractionated cell populations gave both an IgM and an IgG response comparable to controls, whereas the response of the IgM-, IgD- cells was 5- to 20-fold lower. IgG- cells separated 1 day after LPS stimulation could still mount an IgM and IgG response indistinguishable from controls at the peak of the response. It is concluded that IgM+, IgD+, IgG- cells constitute the major LPS-sensitive cell population in the low cell density culture system and that IgG is not a necessary cell surface isotype for precursors of IgG-secreting cells.