Design and Characterization of a Peptide Mimotope of the HIV-1 gp120 Bridging Sheet

作者:Schiavone Marco*; Fiume Giuseppe; Caivano Antonella; de Laurentiis Annamaria; Falcone Cristina; Masci Francesca Fasanella; Iaccino Enrico; Mimmi Selena; Palmieri Camillo; Pisano Antonio; Pontoriero Marilena; Rossi Annalisa; Scialdone Annarita; Vecchio Eleonora; Andreozzi Concetta; Trovato Maria; Rafay Jan; Ferko Boris; Montefiori David; Lombardi Angela; Morsica Giulia; Poli Guido; Quinto Ileana; Pavone Vincenzo; de Berardinis Piergiuseppe; Scala Giuseppe
来源:International Journal of Molecular Sciences, 2012, 13(5): 5674-5699.
DOI:10.3390/ijms13055674

摘要

The Bridging Sheet domain of HIV-1 gp120 is highly conserved among the HIV-1 strains and allows HIV-1 binding to host cells via the HIV-1 coreceptors. Further, the bridging sheet domain is a major target to neutralize HIV-1 infection. We rationally designed four linear peptide epitopes that mimic the three-dimensional structure of bridging sheet by using molecular modeling. Chemically synthesized peptides BS3 and BS4 showed a fair degree of antigenicity when tested in ELISA with IgG purified from HIV+ broadly neutralizing sera while the production of synthetic peptides BS1 and BS2 failed due to their high degree of hydrophobicity. To overcome this limitation, we linked all four BS peptides to the COOH-terminus of GST protein to test both their antigenicity and immunogenicity. Only the BS1 peptide showed good antigenicity; however, no envelope specific antibodies were elicited upon mice immunization. Therefore we performed further analyses by linking BS1 peptide to the NH2-terminus of the E2 scaffold from the Geobacillus Stearothermophylus PDH complex. The E2-BS1 fusion peptide showed good antigenic results, however only one immunized rabbit elicited good antibody titers towards both the monomeric and oligomeric viral envelope glycoprotein (Env). In addition, moderate neutralizing antibodies response was elicited against two HIV-1 clade B and one clade C primary isolates. These preliminary data validate the peptide mimotope approach as a promising tool to obtain an effective HIV-1 vaccine.

  • 出版日期2012-5