The Journal of Immunology · 1987 · 195 citations · 0 references
Life SciencesImmunologyCellular ImmunologyHypersensitivityImmunoregulationCell-mediated ImmunityCytokine BiologyHelper T Cell SubsetsImmune Cell PhysiologyT Cell ActivationT Cell BiologyMucosal Immunoglobulin A (Iga) ResponsesT Cell Cytokine ProductionT Cell ImmunologyT-cell Activation By CytokinesT-cell Modulation
Supernatants from a subset of helper T cell clones can enhance IgA, IgE, and IgG1 production in cultures of lipopolysaccharide-stimulated, T cell-depleted spleen cells. The lymphokine interleukin (IL)-4 has been shown to cause the IgE and IgG1 enhancement produced by these supernatants. IgA enhancement, however, is mediated by a factor distinct from IL-4, although IL-4 can potentiate the effect of the IgA-enhancing factor. IgA-enhancing factor is also distinct from IL-1, IL-2, IL-3, granulocyte-macrophage colony-stimulating factor, and interferon-gamma and acts directly on B cells. Purified IgA-enhancing factor enhances IgA production three- to sixfold yet causes less than a twofold increase in other isotypes. The IgA enhancing activity is not inhibited by concentrations of interferon-gamma that inhibit IL-4 activities. In the accompanying article, we show that this IgA enhancing activity is a novel property of the lymphokine IL-5.