Induction of IgE synthesis in normal human B cells. Sequential requirements for activation by an alloreactive T cell clone and IgE-potentiating factors.
Two human alloreactive T cell clones were established from a one-way mixed lymphocyte culture involving two nonatopic donors, and were assessed for their capacity to induce IgE synthesis by B cells obtained from the original stimulator. The two alloreactive T cell clones studied induced IgG but not IgE synthesis in normal B cells. However, one of the two clones, clone 2H6, induced IgE synthesis in the presence of supernatants from T cell lines derived from patients with the hyper-IgE syndrome (HIE), and enriched for T cells bearing receptors for IgE. These supernatants by themselves caused no IgE synthesis in nonatopic B cells. The potentiating factors in these supernatants were shown to bind to IgE. Time sequence experiments indicated that interaction of the B cells with the alloreactive clone 2H6 renders them responsive to the action of the IgE-potentiating factors. These results indicate that induction of IgE synthesis in normal B cells involves at least two sequential T cell derived signals. Furthermore, T cell clones are heterogenous in their capacity to provide these signals.
D001402:B-Lymphocytes / Q000276:immunology*; D002999:Clone Cells / Q000276:immunology; D006801:Humans; D007073:Immunoglobulin E / Q000096:biosynthesis*; D007074:Immunoglobulin G / Q000096:biosynthesis; D008213:Lymphocyte Activation; D008222:Lymphokines / Q000276:immunology; D029584:Prostatic Secretory Proteins; D011961:Receptors, Fc / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology
D007074:Immunoglobulin G; D008222:Lymphokines; D029584:Prostatic Secretory Proteins; D011961:Receptors, Fc; C043076:beta-microseminoprotein; C013059:immunoglobulin-binding factors; D007073:Immunoglobulin E