Peptide-Derivatized SB105-A10 Dendrimer Inhibits the Infectivity of R5 and X4 HIV-1 Strains in Primary PBMCs and Cervicovaginal Histocultures

Peptide dendrimers are a class of molecules that exhibit a large array of biological effects including antiviral activity. In this
report, we analyzed the antiviral activity of the peptide-derivatized SB105-A10 dendrimer, which is a tetra-branched
dendrimer synthetized on a lysine core, in activated peripheral blood mononuclear cells (PBMCs) that were challenged with
reference and wild-type human immunodeficiency virus type 1 (HIV-1) strains. SB105-A10 inhibited infections by HIV-1 X4
and R5 strains, interfering with the early phases of the viral replication cycle. SB105-A10 targets heparan sulfate
proteoglycans (HSPGs) and, importantly, the surface plasmon resonance (SPR) assay revealed that SB105-A10 strongly binds
gp41 and gp120, most likely preventing HIV-1 attachment/entry through multiple mechanisms. Interestingly, the antiviral
activity of SB105-A10 was also detectable in an organ-like structure of human cervicovaginal tissue, in which SB105-A10
inhibited the HIV-1ada R5 strain infection without altering the tissue viability. These results demonstrated the strong antiviral
activity of SB105-A10 and suggest a potential microbicide use of this dendrimer to prevent the heterosexual transmission of
HIV-1.