title: IL-4 induces co-expression of intrinsic membrane IgG1 and IgE by murine B cells stimulated with lipopolysaccharide.
abstract: IL-4 promotes IgG1 and IgE secretion by murine B cells stimulated with bacterial LPS. We show that stimulation of unprimed resting splenic B cells with LPS and 10(4) U/ml rIL-4 results in the expression of membrane (m) IgG1 and mIgE on 40 to 50% and 15 to 25% of the total B cell population, respectively, on day 4 of culture. The possibility of a significant contribution to cell surface staining by cytophilic, secreted Ig isotypes was eliminated by either the addition of anti-Fc gamma or anti-Fc epsilon R mAb during the culture or by acid treatment before staining. A similar proportion of IgE-expressing B cells are also found, after stimulation with LPS and 10(4) U/ml IL-4, by cytoplasmic staining using fluorescence microscopy. Cell sorting analysis further indicates that B cell populations that express mIgG1 and mIgE secrete these respective Ig isotypes. In addition, such cells show striking diminution in IgM secretion compared to mIgG1- or mIgE- sorted B cells. Stimulation with LPS and IL-4 (10(4) U/ml) induces co-expression of mIgG1 and mIgE on LPS-stimulated B cells; up to 75% of mIgE+ B cells co-express mIgG1 and up to 19% of mIgG1+ B cells express mIgE. This striking co-expression of mIgG1 and mIgE is mirrored by the co-expression of mIgG1 with mIgG3 and mIgG2b by B cells stimulated with LPS and 200 U/ml IL-4. Cell sorting analysis demonstrates that the B cell population that co-expresses mIgG1 and mIgE secretes both IgG1 and IgE. However, "two-color" cytoplasmic staining fails to demonstrate any B cells that simultaneously secrete both IgG1 and IgE.
authors.affiliation: Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, Bethesda, MD 20892.
authors.forename: C M
authors.initials: CM
authors.lastname: Snapper
authors.forename: F D
authors.initials: FD
authors.lastname: Finkelman
authors.forename: D
authors.initials: D
authors.lastname: Stefany
authors.forename: D H
authors.initials: DH
authors.lastname: Conrad
authors.forename: W E
authors.initials: WE
authors.lastname: Paul
mesh_terms: D000085:Acetates; D000818:Animals; D000921:Antibody-Producing Cells / Q000378:metabolism; D001402:B-Lymphocytes / Q000145:classification / Q000276:immunology / Q000378:metabolism*; D003593:Cytoplasm / Q000276:immunology; D005260:Female; D007073:Immunoglobulin E / Q000032:analysis / Q000096:biosynthesis*; D007074:Immunoglobulin G / Q000032:analysis / Q000096:biosynthesis*; D007132:Immunoglobulin Isotypes / Q000032:analysis / Q000096:biosynthesis; D015847:Interleukin-4; D007378:Interleukins / Q000494:pharmacology*; D007700:Kinetics; D008070:Lipopolysaccharides; D008213:Lymphocyte Activation; D051379:Mice; D008811:Mice, Inbred DBA; D011947:Receptors, Antigen, B-Cell / Q000032:analysis / Q000096:biosynthesis*; D013234:Stem Cells / Q000378:metabolism
chemical_list: D000085:Acetates; D007074:Immunoglobulin G; D007132:Immunoglobulin Isotypes; D007378:Interleukins; D008070:Lipopolysaccharides; D011947:Receptors, Antigen, B-Cell; D015847:Interleukin-4; D007073:Immunoglobulin E