FIG 9.

Model summarizing how miR-103 and miR-107 target CCR5 mRNA, leading to less CCR5-mediated HIV-1 entry in macrophages. The exposure of macrophages to the proinflammatory cytokine IL-1β (blue dots) triggers the expression of p53 (red dots). The resulting p53 response activates a set of p53-regulated genes, including miR-103 and miR-107 (yellow), which target CCR5 mRNAs (green) and downregulate their levels, presumably by inducing their degradation. The ensuing reduction of CCR5 expression at the cell surface (broken blue arrow and light green CCR5) limits HIV-1 entry and influences the permissiveness of macrophages to HIV-1 infection. This model highlights miR-103 and miR-107 as important p53-regulated effectors of the antiviral response triggered by the proinflammatory cytokine IL-1β in macrophages.