CD40-activated human naive surface IgD+ B cells produce IgG2 in response to activated T-cell supernatant.
Human IgG2 is an isotype associated with immune responses to carbohydrates. While interleukin-10 (IL-10) induced CD40-activated naive surface (s)IgD+ human B cells to secrete IgG1 and IgG3, none of 20 recombinant cytokines tested alone, or in combination with IL-10, was able to induce these cells to produce IgG2. This was not due to a specific inability of these sIgD+ B cells, as they could be induced to secrete microgram amounts of IgG2, as well as the three other IgG subclasses, when cultured with an anti-CD3-activated CD4+ T-cell clone. The supernatant of this activated CD4+ T-cell clone contained a soluble factor(s) able to induce the secretion of IgG2 by CD40-activated sIgD+ B cells. Following activation, blood T cells also produced a factor(s) inducing CD40-activated naive B cells to secrete IgG2. This CD4+ T-cell clone will thus permit us ultimately to define the presently uncharacterized cytokine(s) inducing naive B cells to secrete IgG2. This will provide a new insight for the study of immunodeficiencies involving a selective defect in IgG2.
Servet-Delprat
C
C
Schering-Plough, Laboratory for Immunological Research, Dardilly, France.
Bridon
J M
JM
Blanchard
D
D
Banchereau
J
J
Brière
F
F
D001402:B-Lymphocytes / Q000276:immunology*; D017252:CD3 Complex / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D019013:CD40 Antigens / Q000276:immunology*; D002478:Cells, Cultured; D017077:Culture Media, Conditioned; D016207:Cytokines / Q000276:immunology; D006801:Humans; D007072:Immunoglobulin D / Q000032:analysis*; D007074:Immunoglobulin G / Q000096:biosynthesis*; D008213:Lymphocyte Activation; D011994:Recombinant Proteins / Q000276:immunology
D017252:CD3 Complex; D019013:CD40 Antigens; D017077:Culture Media, Conditioned; D016207:Cytokines; D007072:Immunoglobulin D; D007074:Immunoglobulin G; D011994:Recombinant Proteins