Mycobacterium tuberculosis Complex Enhances Susceptibility of CD4 T Cells to HIV through a TLR2-Mediated Pathway
Figure 4
Silencing of TLR2 expression attenuates the increased susceptibility to HIV.
Expression of TLR2 increases at the transcription level in cells stimulated with M. bovis BCG when compared to cells stimulated with M. smegmatis (A). The expression levels of TLR4 and TLR9 do not show a significant difference in cells stimulated with different strains of mycobacteria as evidenced by RT-PCR. Comparison of HIV infectivity of CD4+ cells transfected with scrambled siRNA and subsequently stimulated with M. bovis BCG to CD4+ cells transfected with TLR2 siRNA and subsequently stimulated with M. bovis BCG (B) **p<0.005. TLR2 expression on CD4+ cells after stimulation with M. bovis BCG, M. tuberculosis, and M. smegmatis compared to TLR2 expression on CD4+ cells transfected with TLR2 siRNA and subsequently stimulated with M. bovis BCG (C). The expression showed similar trends for the four samples tested. Dot plots comparing the percentage of surface expression of TLR2 on unstimulated CD4+ cells and CD4+ cells stimulated with M. bovis BCG, M. tuberculosis (CDC1551), M. smegmatis (MC2155), and CD4+ cells transfected with TLR2 siRNA and subsequently stimulated with M. bovis BCG (D).