Antibodies generated in cats by a lipopeptide reproducing the membrane-proximal external region of the feline immunodeficiency virus transmembrane enhance virus infectivity.
The immunogenicity of a lipoylated peptide (lipo-P59) reproducing the membrane-proximal external region (MPER) of the transmembrane glycoprotein of feline immunodeficiency virus (FIV) was investigated with cats. In the attempt to mimic the context in which MPER is located within intact virions, lipo-P59 was administered in association with membrane-like micelles. Analyses showed that in this milieu, lipo-P59 had a remarkable propensity to be positioned at the membrane interface, displayed a large number of ordered structures folded in turn helices, and was as active as lipo-P59 alone at inhibiting FIV infectivity in vitro. The antibodies developed differed from the ones previously obtained by immunizing cats with the nonlipoylated version of the peptide (G. Freer, S. Giannecchini, A. Tissot, M. F. Bachmann, P. Rovero, P. F. Serres, and M. Bendinelli, Virology 322:360-369, 2004) in epitope specificity and in the fact that they bound FIV virions. However, they too lacked virus-neutralizing activity and actually enhanced FIV infectivity for lymphoid cell cultures. It is concluded that the use of MPER-reproducing oligopeptides is not a viable approach for vaccinating against FIV.
Giannecchini
Simone
S
Retrovirus Center and Virology Section, Department of Experimental Pathology, University of Pisa, I-56127 Pisa, Italy.
D'Ursi
Anna Maria
AM
Esposito
Cinzia
C
Scrima
Mario
M
Zabogli
Elisa
E
Freer
Giulia
G
Rovero
Paolo
P
Bendinelli
Mauro
M
D000818:Animals; D000914:Antibodies, Viral / Q000097:blood* / Q000276:immunology; D002415:Cats; D002462:Cell Membrane / Q000737:chemistry* / Q000276:immunology; D002942:Circular Dichroism; D007114:Immunization; D016089:Immunodeficiency Virus, Feline / Q000276:immunology / Q000472:pathogenicity*; D008074:Lipoproteins / Q000008:administration & dosage / Q000737:chemistry / Q000276:immunology*; D009682:Magnetic Resonance Spectroscopy; D008562:Membrane Glycoproteins; D008823:Micelles; D009500:Neutralization Tests; D010455:Peptides / Q000008:administration & dosage / Q000138:chemical synthesis / Q000737:chemistry / Q000276:immunology*; D011487:Protein Conformation; D013047:Specific Pathogen-Free Organisms; D014771:Virion / Q000276:immunology
D000914:Antibodies, Viral; D008074:Lipoproteins; D008562:Membrane Glycoproteins; D008823:Micelles; D010455:Peptides