Study on the genotypic resistance of HIV1 in blood monocytes, CD4Tcells and plasma of HIVinfected individuals
Abstract number: P1267
Turriziani O., Boni A., Bucci M., Falasca F., Graziano F., Maida P., Mezzaroma I., Leti W., Fantauzzi A., D'Ettorre G., Vullo V., Antonelli G.
Objective: Reservoirs of HIV-1 are a major obstacle to virus eradication and can potentially compromise the success of therapy. Then there is a need to fully understand the molecular nature of the virus population that persist in cellular reservoirs. This study was aimed to characterise the patterns of resistance of HIV-1 in CD14+ monocyte, CD4+ T cells and plasma.
Methods: Plasma, CD14+ monocyte and CD4+ T cells were collected from 8 treatment-naive individuals and 33 treated-patients; of the latter, 10 showed undectable levels of viraemia and 23 were on virological failure. CD14+ monocyte and CD4+ T cells were isolated using magnetic beads for positive selection (Miltenyi Biotec). Genotyping of the reverse transcriptase (RT) and protease gene (pro) of HIV-1 was performed using fluorescent dideoxy-terminator method (TRUGENE HIV-1-Siemens Heathcare Diagnostics). HIV drug resistance was defined according to the HIV-1 genotypic resistance interpretation algorithm of the GUIDE LINESTM RULE 12.0-BAYER.
Results: Comparison of the amino acid sequence of the RT and pro genes in cell-associated variants of HIV-1 with that of the plasma revealed that in 18 of the 23 "failing" patients (78%) drug resistance mutations were distributed differently from one compartment to another. In only one patient both HIV-1 in monocytes and in CD4+ T cells showed the same pattern of mutations of the virus detected in circulating virus.
As far as concern the group of virological suppress patients, sequence analysis was performed only on cell-associated virus, since all individuals showed undectable level of HIV-RNA (<50 copies/ml). The results obtained revealed that, in 80% of samples, the HIV drug resistant variant harboured in blood monocytes was different from that archived in CD4+T cells.
Only sequences of drug-sensitive virus were found in both compartments of treatment-naive subjects.
Conclusions: Circulating monocytes may harbour a viral dominant population different from the viruses circulating in the blood and archived in other cellular compartments. HIV-infected monocytes can be an indirect source of HIV-1 by carrying virus and differentiating into tissue macrophage where HIV may productively replicate. Hence, blood monocytes might serve as an indirect source of drug-resistant viral variant.
|Session name:||19th European Congress of Clinical Microbiology and Infectious Diseases|
|Location:||Helsinki, Finland, 16 - 19 May 2009|
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