Inhibition of HIV and M. tuberculosis by 1,25D3 is CAMP and autophagy dependent.
MDM were transduced with non-specific scrambled shRNA (shNS) or CAMP shRNA (shCAMP) and selected using puromycin resistance. Five days later, cells were incubated with 100 pmol/L 1,25D3 or vehicle control for 4 h before infection with HIV and/or M. tuberculosis (TB) for 3 h. Cells were then washed and incubated with 100 pmol/L 1,25D3 or vehicle control for 7 days. (A) Immunoblot analysis performed using antibodies raised to CAMP or β-actin after initial pathogen exposure (Day 0) or after 7 days. (B) Day 7 HIV-1Ba-L and TB co-infected cells were harvested and stained for saponin-resistant LC3B-II at day 7. A representative histogram from three donors are shown. (C) ELISA performed for HIV p24 antigen release over 7 d. (D) Intracellular mycobacteria were harvested and assayed for mycobacterial growth by cfu enumeration at day 0 and day 7. All bar and line graphs are reported as mean ± s.e.m. of three independent experiments performed in triplicate. * P<0.001.