CCR5 and infection: Furthermore, transfection of HOS-CD4-CCR5 cells with increasing amounts of pEZX-miR-155 plasmid, but not with pEZX-scrambled control plasmid, resulted in a dose-dependent decrease in infection with both HIV-1 envelope- and VSV-G-pseudotyped viruses, which correlated with a dose-dependent increase in miR-155 levels (Figure 5C–D).