Amino acid substitutions in Gag protein at non-cleavage sites are indispensable for the development of a high multitude of HIV-1 resistance against protease inhibitors.
Amino acid substitutions in human immunodeficiency virus type 1 (HIV-1) Gag cleavage sites have been identified in HIV-1 isolated from patients with AIDS failing chemotherapy containing protease inhibitors (PIs). However, a number of highly PI-resistant HIV-1 variants lack cleavage site amino acid substitutions. In this study we identified multiple novel amino acid substitutions including L75R, H219Q, V390D/V390A, R409K, and E468K in the Gag protein at non-cleavage sites in common among HIV-1 variants selected against the following four PIs: amprenavir, JE-2147, KNI-272, and UIC-94003. Analyses of replication profiles of various mutant clones including competitive HIV-1 replication assays demonstrated that these mutations were indispensable for HIV-1 replication in the presence of PIs. When some of these mutations were reverted to wild type amino acids, such HIV-1 clones failed to replicate. However, virtually the same Gag cleavage pattern was seen, indicating that the mutations affected Gag protein functions but not their cleavage sensitivity to protease. These data strongly suggest that non-cleavage site amino acid substitutions in the Gag protein recover the reduced replicative fitness of HIV-1 caused by mutations in the viral protease and may open a new avenue for designing PIs that resist the emergence of PI-resistant HIV-1.
Gatanaga
Hiroyuki
H
Experimental Retrovirology Section, HIV and AIDS Malignancy Branch, NCI, National Institutes of Health, Bethesda, Maryland 20892, USA.
Suzuki
Yasuhiro
Y
Tsang
Hsinyi
H
Yoshimura
Kazuhisa
K
Kavlick
Mark F
MF
Nagashima
Kunio
K
Gorelick
Robert J
RJ
Mardy
Sek
S
Tang
Chun
C
Summers
Michael F
MF
Mitsuya
Hiroaki
H
D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D019380:Anti-HIV Agents / Q000494:pharmacology; D002219:Carbamates; D002460:Cell Line; D003001:Cloning, Molecular; D004352:Drug Resistance, Microbial; D005663:Furans; D015683:Gene Products, gag / Q000737:chemistry / Q000378:metabolism*; D017320:HIV Protease Inhibitors / Q000494:pharmacology*; D015497:HIV-1 / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development; D006801:Humans; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D015183:Restriction Mapping; D013449:Sulfonamides / Q000494:pharmacology
D019380:Anti-HIV Agents; D002219:Carbamates; D005663:Furans; D015683:Gene Products, gag; D017320:HIV Protease Inhibitors; D011994:Recombinant Proteins; D013449:Sulfonamides; C095108:amprenavir