Rev-derived peptides inhibit HIV-1 replication by antagonism of Rev and a co-receptor, CXCR4

Rev, a viral regulatory protein of HIV-1, binds through its arginine-rich domain to the Rev-responsive element (RRE), a secondary structure in transcribed HIV-1 RNA. Binding of Rev to RRE mediates export of singly spliced or unspliced mRNAs from the nucleus to the cytoplasm. It has been previously shown that a certain arginine-rich peptide exhibits not only RRE-binding ability but also cell permeability and antagonism of CXCR4, one of the major coreceptors of HIV-1. Here we designed and synthesized arginine-rich peptides derived from the RNA-binding domain of Rev (Rev34-50) and evaluated their anti-HIV-1 activities. Rev34-50-A4C, comprising Rev34-50 with AAAAC at the C-terminus to increase the α-helicity, inhibited HIV-1 entry by CXCR4 antagonism and virus production in persistently HIV-1-infected PM1-CCR5 cells. Interestingly, similar motif of human lymphotropic virus type I Rex (Rex1-21) also exerted moderate anti-HIV-1 activity. These results indicate that arginine-rich peptide, Rev34-50-A4C exerts dual antagonism against CXCR4 and Rev.