TLR2 and HIV-1 infection: It was reported that commensal bacteria such as Escherichia coli, Veillonella parvula, and Neisseria mucosa suppressed HIV-1 expression by stimulating TLR4 signaling, whereas other commensal bacteria such as Lactobacillus acidophilus, Prevotella melaninogenica, P. bivia, and Mycobacterium smegmatis enhanced HIV-1 infection by stimulating TLR2 signaling[5].