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 2 months) 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.

Svicher, V., Balestra, E., Cento, V., Sarmati, L., Dori, L., Vandenbroucke, I., et al. (2011). HIV-1 dual/mixed tropic isolates show different genetic and phenotypic characteristics and response to maraviroc in vitro. ANTIVIRAL RESEARCH, 90(1), 42-53 [10.1016/j.antiviral.2011.02.005].

HIV-1 dual/mixed tropic isolates show different genetic and phenotypic characteristics and response to maraviroc in vitro

SVICHER, VALENTINA;BALESTRA, EMANUELA;SARMATI, LOREDANA;SACCOMANDI, PATRIZIA;AQUARO, STEFANO;ANDREONI, MASSIMO;CECCHERINI SILBERSTEIN, FRANCESCA;PERNO, CARLO FEDERICO
2011-04-01

Abstract

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 2 months) 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.
apr-2011
Pubblicato
Rilevanza internazionale
Articolo
Sì, ma tipo non specificato
Settore MED/07 - MICROBIOLOGIA E MICROBIOLOGIA CLINICA
Settore MED/17 - MALATTIE INFETTIVE
English
Con Impact Factor ISI
Svicher, V., Balestra, E., Cento, V., Sarmati, L., Dori, L., Vandenbroucke, I., et al. (2011). HIV-1 dual/mixed tropic isolates show different genetic and phenotypic characteristics and response to maraviroc in vitro. ANTIVIRAL RESEARCH, 90(1), 42-53 [10.1016/j.antiviral.2011.02.005].
Svicher, V; Balestra, E; Cento, V; Sarmati, L; Dori, L; Vandenbroucke, I; D'Arrigo, R; Buonomini, A; Van Marck, H; Surdo, M; Saccomandi, P; Mostmans, ...espandi
Articolo su rivista
File in questo prodotto:
File Dimensione Formato  
HIV-1 dual mixed tropic isolates show different genetic and phenotypic characteristics and response to maraviroc in vitro.pdf

accesso aperto

Licenza: Creative commons
Dimensione 385.82 kB
Formato Adobe PDF
385.82 kB Adobe PDF Visualizza/Apri

Questo articolo è pubblicato sotto una Licenza Licenza Creative Commons Creative Commons

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2108/18796
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 25
  • ???jsp.display-item.citation.isi??? 23
social impact