FIG. 4.

Secretion of the tumor necrosis factor (TNF)-α and interleukin-10 (IL-10) in U937 infected with recombinant M. smegmatis strains measured by ELISA. (A, B) U937 were infected at an MOI of 10:1 with M. smegmatis containing vector only (□), PE_PGRS 17 (▪) and incubated for different time duration. Culture supernatants were collected at indicated intervals and used to quantify the production of TNF-α and IL-10 by the ELISA kit. (A) The secretion of TNF-α is significantly higher by macrophages infected with M. smegmatis expressing PE_PGRS 17 than the control group at 24 h and 30 h post-infection. (B) The release of IL-10 in macrophages is much higher by the control group at 6 h after infection. Each treatment was repeated three times.