Previous Article | Next Article ![]()
J. Virol., 02 1996, 1086-1090, Vol 70, No. 2
AK Iversen, RW Shafer, K Wehrly, MA Winters, JI Mullins, B Chesebro and TC Merigan
Multidrug-resistant human immunodeficiency virus type 1 (HIV-1) strains
with reverse transcriptase (RT) mutations at codons A62-->V, V75-->I,
F77-->L, F116-->Y, and Q151-->M have been reported in patients
receiving combination therapy with zidovudine (AZT) and didanosine (ddI).
Infectious clones with each mutation alone, all five mutations together,
and various combinations of mutations were created by site- directed
mutagenesis. Mutation Q151-->M conferred partial resistance to AZT, ddI,
zalcitibine, and stavudine, whereas a combination of four mutations
conferred increased resistance to AZT, ddI, zalcitibine, and stavudine. The
positions of residues 75, 77, and 151 in the three- dimensional crystal
structure of HIV-1 RT suggest that these residues may affect the ability of
the enzyme to discriminate between deoxynucleoside triphosphates and
nucleoside analog RT inhibitors. Replication experiments showed that clones
with mutation F77-->L but without V75-->I (HIV-1(77), HIV-1(77,151),
and HIV-1(77,116,151) had attenuated growth compared with that of the
original HIV-1NL4-3 strain and strains containing mutations at both
positions 75 and 77 (HIV- 1(75,77,151) and HIV-1(75,77,116,15)). Sequence
analysis of viral RNA and proviral DNA from several patients indicated that
RT mutations developed in a sequential and cumulative pattern over the
course of a 2- to 4-year observation period. The present results suggest
that drug resistance and viral replicative capacity both may play a role in
selection of HIV-1 RT mutations.
Copyright © 1996, American Society for Microbiology
Multidrug-resistant human immunodeficiency virus type 1 strains resulting from combination antiretroviral therapy
Division of Infectious Diseases and Geographic Medicine, Stanford University, California 94305, USA.
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»