RNASEL and HIV-1 infection: HIV-1 5' UTR RNA binds 2-5OAS resulting in RNAseL activity in vitro. HIV-1 infection is associated with reduced interferon production and reduced 2-5A:RNAseL binding, allowing HIV-1 mRNA to evade cleavage by RNaseL. HTLV-1 RxRE activates 2-5OAS in vitro.