TY - JOUR
T1 - HIV-1 dual/mixed tropic isolates show different genetic and phenotypic characteristics and response to maraviroc in vitro
AU - Svicher, Valentina
AU - Balestra, Emanuela
AU - Cento, Valeria
AU - Sarmati, Loredana
AU - Dori, Luca
AU - Vandenbroucke, Ina
AU - D'Arrigo, Roberta
AU - Buonomini, Anna Rita
AU - Van Marck, Herwig
AU - Surdo, Matteo
AU - Saccomandi, Patrizia
AU - Mostmans, Wendy
AU - Aerssens, Jeroen
AU - Aquaro, Stefano
AU - Stuyver, Lieven J.
AU - Andreoni, Massimo
AU - Ceccherini-Silberstein, Francesca
AU - Perno, Carlo Federico
PY - 2011/4
Y1 - 2011/4
N2 - Dual/mixed-tropic HIV-1 strains are predominant in a significative proportion of patients, though few information is available regarding the genetic characteristics, quasispecies composition, and susceptibility against CCR5-antagonists of the primary-isolates. For this reason, we investigated in deep details, both phenotypically and genotypically, the characteristics of 54 HIV-1 primary-isolates obtained from HIV-infected patients. Tropism was assessed by multiple-cycles phenotypic-assay on U87MG-CD4+-CCR5+-/CXCR4+-expressing cells. In vitro selection in PBMCs of X4-tropic viral strains following maraviroc-treatment was also performed.Phenotypic-assay reported pure R5-tropic viruses in 31 (57.4%) isolates, dual/mixed-tropic viruses in 22 (40.7%), and pure X4-tropic virus in only 1 (1.8%). Among dual/mixed-tropic isolates, 12 showed a remarkably higher replication-efficacy in CCR5-expressing cells (R5+/X4), and 2 in CXCR4-expressing cells (R5/X4+). Genotypic-tropism testing showed a correlation between PSSM-scores, geno2pheno false-positive-rate, and V3-net-charge with both CCR5-usage and syncytium-inducing ability. Moreover, specific gp120- and gp41-mutations were significantly associated with tropism and/or syncytium-inducing ability.Ultra-deep V3-pyrosequencing showed the presence of a swarm of genetically distinct species with a preference for CCR5-coreceptor not only in all pure R5-isolates, but also in 6/7 R5+/X4-tropic isolates. In both pure-X4 and R5/X4+-isolates, we observed extensive prevalence of X4-using species. In vitro selection-experiments with CCR5-inhibitor maraviroc (up to 2months) showed no-emergence of X4-tropic variants for all R5- and R5+/X4-isolates tested (while X4-virus remained fully-resistant).In conclusion, our study shows that dual/mixed-tropic viruses are constituted by different species, whereby those with characteristics R5+/X4 are genotypically and phenotypically similar to the pure-R5 isolates; thus the use of CCR5-antagonists in patients with R5+/X4-tropic viruses may be a therapeutic-option that deserves further investigations.
AB - Dual/mixed-tropic HIV-1 strains are predominant in a significative proportion of patients, though few information is available regarding the genetic characteristics, quasispecies composition, and susceptibility against CCR5-antagonists of the primary-isolates. For this reason, we investigated in deep details, both phenotypically and genotypically, the characteristics of 54 HIV-1 primary-isolates obtained from HIV-infected patients. Tropism was assessed by multiple-cycles phenotypic-assay on U87MG-CD4+-CCR5+-/CXCR4+-expressing cells. In vitro selection in PBMCs of X4-tropic viral strains following maraviroc-treatment was also performed.Phenotypic-assay reported pure R5-tropic viruses in 31 (57.4%) isolates, dual/mixed-tropic viruses in 22 (40.7%), and pure X4-tropic virus in only 1 (1.8%). Among dual/mixed-tropic isolates, 12 showed a remarkably higher replication-efficacy in CCR5-expressing cells (R5+/X4), and 2 in CXCR4-expressing cells (R5/X4+). Genotypic-tropism testing showed a correlation between PSSM-scores, geno2pheno false-positive-rate, and V3-net-charge with both CCR5-usage and syncytium-inducing ability. Moreover, specific gp120- and gp41-mutations were significantly associated with tropism and/or syncytium-inducing ability.Ultra-deep V3-pyrosequencing showed the presence of a swarm of genetically distinct species with a preference for CCR5-coreceptor not only in all pure R5-isolates, but also in 6/7 R5+/X4-tropic isolates. In both pure-X4 and R5/X4+-isolates, we observed extensive prevalence of X4-using species. In vitro selection-experiments with CCR5-inhibitor maraviroc (up to 2months) showed no-emergence of X4-tropic variants for all R5- and R5+/X4-isolates tested (while X4-virus remained fully-resistant).In conclusion, our study shows that dual/mixed-tropic viruses are constituted by different species, whereby those with characteristics R5+/X4 are genotypically and phenotypically similar to the pure-R5 isolates; thus the use of CCR5-antagonists in patients with R5+/X4-tropic viruses may be a therapeutic-option that deserves further investigations.
KW - Env mutations
KW - HIV-1 tropism
KW - Maraviroc
KW - Phenotyping
KW - Pyrosequencing
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U2 - 10.1016/j.antiviral.2011.02.005
DO - 10.1016/j.antiviral.2011.02.005
M3 - Article
C2 - 21349294
AN - SCOPUS:79953714840
SN - 0166-3542
VL - 90
SP - 42
EP - 53
JO - Antiviral Research
JF - Antiviral Research
IS - 1
ER -