Fig. 4.

Interference of LAMP-3 expression inhibits intracellular proliferation of Salmonella typhimurium. (A) Stable control (Scrambled) or LAMP-3 knockdown HeLa cell line was checked for the level of down-regulation of LAMP-3 expression by western blotting using antibody against LAMP-3. GAPDH expression was checked as a loading control. (B) Intracellular proliferation of Salmonella was assayed according to the procedure in the materials and methods. The 2, 6 and 12 h after infection, the cells were lyzed with lysis buffer to isolate live bacteria in the LB agar plate containing 100 ug/ml of Ampicillin. After, overnight, the number of bacteria colonies was counted and compared to that of control cell line. Data are the average of three independent experiments. Error bars represent standard deviation. (C) LAMP-2 knockdown HeLa cell line was established and the level of LAMP-2 down-regulation was checked by Western blotting with anti-LAMP-2 antibody. (D) Intra cellular survival assay was performed with LAMP-2 K/D cell line and scrambled control cell line at 2 and 6 h after the Salmonella infection.