Determinants of human immunodeficiency virus type 1 resistance to membrane-anchored gp41-derived peptides.
The expression of a membrane-anchored gp41-derived peptide (M87) has been shown to confer protection from infection through human immunodeficiency virus type 1 (HIV-1) (Hildinger et al., J. Virol. 75:3038-3042, 2001). In an effort to characterize the mechanism of action of this membrane-anchored peptide in comparison to the soluble peptide T-20, we selected resistant variants of HIV-1(NL4-3) and HIV-1(BaL) by serial virus passage using PM1 cells stably expressing peptide M87. Sequence analysis of the resistant isolates showed different patterns of selected point mutations in heptad repeat regions 1 and 2 (HR1 and HR2, respectively) for the two viruses analyzed. For HIV-1(NL4-3) a single amino acid change at position 33 in HR1 (L33S) was selected, whereas for HIV-1(BaL) the majority of the sequences obtained showed two amino acid changes, one in HR1 and one in HR2 (I48V/N126K). In both selections the most important contiguous 3-amino-acid sequence, GIV, within HR1, associated with resistance to soluble T-20, was not changed. Site-directed mutagenesis studies confirmed the importance of the characterized point mutations to confer resistance to M87 as well as to soluble T-20 and T-649. Replication capacity and dual-color competition assays revealed that the double mutation I48V/N126K in HIV-1(BaL) results in a strong reduction of viral fitness, whereas the L33S mutation in HIV-1(NL4-3) did enhance viral fitness compared to the respective parental viruses. However, the selected point mutations did not confer resistance to the more recently described optimized membrane-anchored fusion inhibitor M87o (Egelhofer et al., J. Virol. 78:568-575, 2004), strengthening the importance of this novel antiviral concept for gene therapy approaches.
Lohrengel
Sabine
S
Abt. Virologie, Hygiene-Institut, Universität Heidelberg, D-69120 Heidelberg, Germany.
Hermann
Felix
F
Hagmann
Isabel
I
Oberwinkler
Heike
H
Scrivano
Laura
L
Hoffmann
Caroline
C
von Laer
Dorothee
D
Dittmar
Matthias T
MT
D000595:Amino Acid Sequence; D024882:Drug Resistance, Viral; D000077560:Enfuvirtide; D015700:HIV Envelope Protein gp41 / Q000737:chemistry / Q000235:genetics / Q000494:pharmacology*; D023581:HIV Fusion Inhibitors / Q000494:pharmacology*; D015497:HIV-1 / Q000187:drug effects*; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010446:Peptide Fragments / Q000494:pharmacology*; D017354:Point Mutation; D014779:Virus Replication
D015700:HIV Envelope Protein gp41; D023581:HIV Fusion Inhibitors; D010446:Peptide Fragments; D000077560:Enfuvirtide