Fig. 4. Effect of overexpression of CD40 on the induction of NO production in BV-2 microglial cells.

Cells plated at 50–60% confluence in six-well plates were transfected with different amounts of either CD40 cDNA or an empty vector using LipofectAMINE Plus as described under “Materials and Methods.” After 24 h of transfection, cells were stimulated with anti-CD40 (1 μg/ml) in the presence or absence of IFN-γ (10 units/ml) under serum-free conditions. After 24 h of stimulation, supernatants were used for the nitrite assay. Data are expressed as the mean of two separate experiments.