Interleukin (IL) 4 counteracts the helper effect of IL2 on antigen-activated human B cells.
We tested the effect of interleukin (IL) 4 on the specific IgM antibody response induced by trinitrophenylated-polyacrylamide beads (TNP-PAA) in cultures of human B cells. T cell help was provided by exogeneous IL2. IL4 profoundly suppressed the response to optimal concentrations (50 U/ml) of IL2, with a 50% inhibitory concentration of 6 U/ml. This was due neither to a shift in the kinetics nor to a switch to an IgG response. The production of anti-TNP antibody (as measured by an enzyme-linked immunosorbent assay in the culture supernatant) was inhibited to the same extent as the generation of plaque-forming cells. The effect of IL4 was completely abolished by a neutralizing antibody toward IL4. Kinetic studies showed that IL4 had to be present during the first 48 h of culture to fully inhibit the response. The sequential stimulation of B cells by antigen and by IL2 showed that IL4 does not negatively interfere with signaling through membrane Ig but counteracts the effect of IL2 on antigen-activated B cells.
Llorente
L
L
INSERM U131, Clamart, France.
Crevon
M C
MC
Karray
S
S
Defrance
T
T
Banchereau
J
J
Galanaud
P
P
D000917:Antibody Formation / Q000187:drug effects*; D000937:Antigen-Antibody Reactions; D001402:B-Lymphocytes / Q000276:immunology*; D004334:Drug Administration Schedule; D006801:Humans; D066298:In Vitro Techniques; D007376:Interleukin-2 / Q000037:antagonists & inhibitors*; D015847:Interleukin-4; D007378:Interleukins / Q000008:administration & dosage / Q000494:pharmacology*; D013997:Time Factors; D014301:Trinitrobenzenes / Q000276:immunology
D007376:Interleukin-2; D007378:Interleukins; D014301:Trinitrobenzenes; D015847:Interleukin-4