Marked increase in anti-HIV activity, as well as inhibitory activity against HIV entry mediated by CXCR4, linked to enhancement of the binding ability of tachyplesin analogs to CXCR4.
T22 ([Tyr5,12, Lys7]-polyphemusin II) is a strong anti-HIV compound. Six analogs of T22 and two natural forms were synthesized. Of them, all downsized peptides (14 residues; TW70, T131, T134, and T140) showed a higher selectivity index than did other, 17- or 18-residue peptides. In particular, T134 and T140 showed both lower cytotoxicity and higher antiviral activity than did T22 against HIV infection of MT-4 cells, an HTLV-I-bearing T cell line. To clarify the inhibitory mode of T22 and its analogs, we used a single-round replication assay (luciferase assay), in which different envelope-bearing pseudotypes were used to infect CXCR4- or CCR5-bearing U87 cells via CD4. All of the analogs inhibited T cell line-tropic strain HXB-2 (X4) and dual-tropic strain 89.6 (R5X4) HIV infections mediated by CXCR4, but had no effect on macrophage-tropic strain ADA (R5) or 89.6 HIV infections mediated by CCR5. The inhibition by T134 (IC50 of 2.70 nM) and T140 (IC50 of 0.432 nM) was also stronger than that by T22 (IC50 of 5.05 nM). The binding of anti-CXCR4 monoclonal antibody 12G5 to lymphoma-derived T cell line Sup-T1 was more efficiently blocked by T134 and T140 than by T22. Taken together, T22 and its analogs T134 and T140 exerted their inhibition by specific binding to CXCR4. The marked increase in the anti-HIV activity of T134 and T140 was ascribed to an enhancement in their ability to bind to CXCR4.
Xu
Y
Y
Laboratory of Virus Immunology, Research Center for Acquired Immunodeficiency Syndrome, Institute for Virus Research, Kyoto University, Japan.
Tamamura
H
H
Arakaki
R
R
Nakashima
H
H
Zhang
X
X
Fujii
N
N
Uchiyama
T
T
Hattori
T
T
D000595:Amino Acid Sequence; D019380:Anti-HIV Agents / Q000494:pharmacology*; D000911:Antibodies, Monoclonal; D023181:Antimicrobial Cationic Peptides; D002460:Cell Line; D003588:Cytopathogenic Effect, Viral; D004268:DNA-Binding Proteins / Q000138:chemical synthesis / Q000378:metabolism* / Q000494:pharmacology; D005434:Flow Cytometry; D005822:Genetic Vectors; D015658:HIV Infections / Q000821:virology; D015497:HIV-1 / Q000187:drug effects* / Q000235:genetics / Q000472:pathogenicity; D006801:Humans; D008156:Luciferases / Q000378:metabolism; D008969:Molecular Sequence Data; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D010456:Peptides, Cyclic / Q000138:chemical synthesis / Q000378:metabolism* / Q000494:pharmacology; D019718:Receptors, CXCR4 / Q000378:metabolism*; D014759:Viral Envelope Proteins / Q000235:genetics
D019380:Anti-HIV Agents; D000911:Antibodies, Monoclonal; D023181:Antimicrobial Cationic Peptides; D004268:DNA-Binding Proteins; D010455:Peptides; D010456:Peptides, Cyclic; D019718:Receptors, CXCR4; D014759:Viral Envelope Proteins; C057636:tachyplesin peptide, Tachypleus tridentatus; C062386:polyphemusin II; D008156:Luciferases