Interleukin 4 acts on both high- and low-density murine B cell subpopulations to induce IgE and IgG1 synthesis in vitro.
Murine B cells were activated for 24 h with either lipopolysaccharide (LPS) or polyribosyl-ribitol-phosphate (PRP), followed by addition of interleukin 4 (IL-4) and the immunoglobulin isotypes secreted into the supernatant quantitated. Without IL-4, both LPS and PRP induced mainly IgM and IgG3 and no IgE secretion. Addition of IL-4 to both LPS- and PRP-activated cells decreased the IgM and IgG3 secretion and induced a large IgG1 production. In contrast to IgG1, only LPS-activated cells secreted large amounts of IgE, demonstrating that the nature of the polyclonal B cell activator also plays an important role in the IL-4 induced IgE formation. The effect of LPS and IL-4 on high- and low-density sIgM+/sIgD+ cells was also investigated. LPS and IL-4 induced IgG1 and IgE secretion by both populations. Low-density B cells from mice infected with the parasite Nippostrongylus brasiliensis formed more IgE than low-density B cells from normal mice, presumably because these mice have more in vivo preactivated B cells committed to IgE formation. The data show that IL-4 can act on both small high-density resting B cells as well as on in vivo preactivated low-density B cells to induce IgG1 and IgE secretion.
Lebrun
P
P
Department of Immunology, Research Institute of Scripps Clinic, La Jolla, Calif.
Lucas
A H
AH
McKenzie
D T
DT
Spiegelberg
H L
HL
D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology*; D002499:Centrifugation, Density Gradient; D007073:Immunoglobulin E / Q000096:biosynthesis*; D007074:Immunoglobulin G / Q000096:biosynthesis*; D015847:Interleukin-4; D007378:Interleukins / Q000494:pharmacology*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008213:Lymphocyte Activation; D051379:Mice
D007074:Immunoglobulin G; D007378:Interleukins; D008070:Lipopolysaccharides; D015847:Interleukin-4; D007073:Immunoglobulin E