Since phagocytosis of Selleckchem Androgen Receptor Antagonist bacilli by normal and by PKC-α deficient cells was different, we presented the selleck products survival of BCG as fold increase in the number of intracellular bacilli as compared to the initial phagocytosis (Fig. 2C). The specifiCity of PKC-α SiRNA was confirmed by transfecting mouse macrophage cell line, J774A.1 and showing that SiRNA blocked PKC-α, only in THP-1 cells (data not shown). Figure 2 Phagocytosis and survival of BCG in PKC-α deficient THP-1 cells. THP-1 cells were incubated
in the presence of 30 nM PMA for 24 h. Then cells were transfected with 20 nM SiRNA and level of PKC-α were determined by immunoblotting. (A) 24 h after transfection, level of PKC-α and PKC-δ in cells transfected with SiRNA targeting PKC-α or scrambled SiRNA, (B) 24 h after transfection, (ΔA) cells transfected with SiRNA targeting PKC-α and (S) cells transfected with scrambled SiRNA and control cells (C) were infected with BCG (MOI = 1:10) for 2 h, washed and remaining extracellular bacilli were killed by amikacin treatment selleck chemicals llc for 1 h and lysed in 0.05% SDS and plated. Colony forming units (cfu) were determined after 4 week of incubation. Tukey (T) test was performed for statistical analysis of data (C) Survival of BCG in THP-1 cells transfected with either SiRNA targeting PKC-α (ΔA) or scrambled
SiRNA (S) after 24 and 48 h, since phagocytosis of BCG in control and PKC-α deficient cells was different, CFU at 0 Baf-A1 chemical structure h was considered 1 and survival of BCG is presented as fold increase in the number of cfu as compared to the initial phagocytosis. Data are means ± standard deviations from three independent experiments each performed in 4 replicates. (** = p < 0.005). To clearly understand the specific role of PKC-α in the phagocytosis and survival of mycobacteria,
we used MS (which does not downregulate PKC-α) for infection. Knockdown of PKC-α resulted in the significant (p < 0.0001) decrease in the phagocytosis of MS by macrophages (Fig. 3A). Results show that phagocytosis of MS is 2.6 fold less in PKC-α deficient cells as compared to normal cells. Inhibition of phagocytosis was specific to the inhibition of PKC-α as knockdown of PKC-δ did not inhibit the phagocytosis or survival (Fig. 3A, 3B and 3C). When survival of MS in macrophages deficient in PKC-α was compared with normal cells, we found that survival of MS was increased in the PKC-α deficient macrophages. Since phagocytosis of MS by normal and PKC-α deficient cells was different, we expressed intracellular survival of MS as percentage of the initial bacilli uptake. In normal macrophages, only 25% of initial bacilli survived as contrast to 65% survival in PKC-α deficient cells (Fig. 3B). The results were confirmed with J774A.1 cells using Go6976 (inhibitor of PKC-α) which represented similar level of inhibition in phagocytosis (Fig. 3D). Figure 3 Phagocytosis and survival of MS in PKC-α deficient THP-1 cells.