Table I.

Effect of IFNγ Neutralization on IL-4 Production in Several Mouse Strains

Strain	C57BL/6	129S6/SvEv	B10.A	C57BL/6 IFNγ−/−
Priming
IL-4	34.5	26.3	23.7	13.5
IL-4 and anti-IFNγ	21.1	9.2	15.4	13.9

LN-derived CD4⁺ T cells derived from indicated mouse strains were stimulated for 4 d with 5 μg/ml of plate-bound anti-CD3⁺ anti-CD28 in the presence of 10 U/ml IL-2 and IL-4 at 1,000 U/ml without or with 10 μg/ml IFNγ-blocking mAbs. Cells were restimulated for 6 h with 5 μg/ml plate-bound anti-CD3 and anti-CD28. Percentages of IL-4 in the cultures were evaluated by intracellular staining and FACS^®. Cultures of CD4 cells derived from the IFNγ-deficient strain served as a control.