FIG. 1.

Effect of CD40L-293 cells and CD40LT on intracellular growth of M. avium in MDM. M. avium-infected MDM were cocultured with CD40L-293 cells or CD40LT in the presence and absence of MAbs against CD40L and CD40 for up to 7 days. Intracellular growth of M. avium was assessed by the CFU assay on days 1, 3, and 7 after infection. Each condition was tested in triplicate, and results are expressed as mean CFU per well ± SD. (A) M. avium-infected MDM cultured with CD40L-293 cells; (B) M. avium-infected MDM cultured with CD40L-293 cells or control pcDNA-293 cells in the presence and absence of MAb against CD40L (10 μg/ml), CD40 (10 μg/ml), or control mouse IgG κ chain (10 μg/ml); (C) M. avium-infected MDM cultured with recombinant CD40LT at 1 or 5 μg/ml or medium alone; (D) M. avium-infected MDM cultured with CD40LT in the presence and absence of MAb against CD40L (10 μg/ml), CD40 (10 μg/ml), or control mouse IgG κ chain (10 μg/ml). Results shown are representative of three experiments.