In this study, we found that stimulation of normal human monocyte-derived macrophages (MDMs) from multiple donors with poly(I∶C) or LPS, but not with the ligands for TLR7 (Imiquimod) or TLR9 (CpG), consistently abrogates their susceptibility to infection by CCR5-using, macrophage-tropic HIV-1, and by vesicular stomatitis virus glycoprotein (VSV-G)-pseudotyped virions, suggesting a post-entry restriction mechanism. This evidence concerns the gene TLR9 and infection.