title: Surface Ig isotypes on cells responding to lipopolysaccharide by IgM and IgG secretion.
abstract: 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.
mesh_terms: D000818:Animals; D000921:Antibody-Producing Cells / Q000276:immunology*; D002469:Cell Separation; D004306:Dose-Response Relationship, Immunologic; D005260:Female; D005455:Fluorescent Antibody Technique; D007072:Immunoglobulin D; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D011817:Rabbits; D051381:Rats; D011917:Rats, Inbred Lew; D011947:Receptors, Antigen, B-Cell / Q000276:immunology*; D013154:Spleen / Q000276:immunology; D013997:Time Factors
chemical_list: D007072:Immunoglobulin D; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D008070:Lipopolysaccharides; D011947:Receptors, Antigen, B-Cell