title: A synergistic polyclonal response to dextran sulphate and lipopolysaccharide: immunoglobulin secretion and cell requirements.
abstract: The effects of the simultaneous addition of lipopolysaccharide (LPS) and dextran sulphate (DxS) were studied in a low-cell density culture system, which enables extensive cell proliferation and high immunoglobulin secretion. Using these two mitogens, a synergistic response was observed, with regard to both cell division and IgM secretion. However, only a very low IgG production could be detected. This was caused by the extensive cell proliferation, leading to suboptimal culture conditions. Thus, when the blasts were recultured at a lower density or when a lower initial cell concentration was used, a high IgG response was obtained. The synergistic response induced by LPS plus DxS was independent of T cells. Furthermore, no apparent need for phagocytic cells was found. Both the LPS- and the LPS plus DxS-induced activation led to a switch, preferentially to IgG2b and IgG3 secretion. This subclass pattern was not changed when the cultures were lacking functional T cells.
mesh_terms: D000818:Animals; D002450:Cell Communication; D016264:Dextran Sulfate; D003911:Dextrans / Q000494:pharmacology*; D005260:Female; D007074:Immunoglobulin G / Q000096:biosynthesis; D007075:Immunoglobulin M / Q000096:biosynthesis; D007136:Immunoglobulins / Q000096:biosynthesis*; D066298:In Vitro Techniques; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008213:Lymphocyte Activation; D008264:Macrophages / Q000276:immunology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D003911:Dextrans; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007136:Immunoglobulins; D008070:Lipopolysaccharides; D016264:Dextran Sulfate