title: Accumulation of defective HIV-1 variants in a patient with slow disease progression.
abstract: Viral population in a long term non progressor carrying CRF02-AG HIV-1 virus variants with a truncated RT gene and attenuated virus replication was analyzed. The proportion of mutant and wild-type RT sequences was determined by clonal analysis of HIV-1 DNA and RNA from blood samples and peripheral blood mononuclear cell (PBMC) culture supernatants. Recombinant HIV-1 strains were generated by reverse genetics to evaluate the replicative capacity of RT variants in PBMC cultures. HIV-1 RNA and DNA sequences in PBMC cultures showed a mixture of stop codons (RT(STOP)), recombinant forms, (RT(RF)), and full length (RT(FL)) strains. In plasma, proportion of HIV-1 RNA sequences with a truncated RT gene fluctuated over time (0% in 2005, 100% in 2007 and 8.3% in 2010), while in proviral DNA was constant (96.5% to 100%). Reconstituted RT(STOP) strains were unable to replicate in PBMC. However, RT(FL) strains could trans-complement the loss of function of RT(STOP) variants. In vivo selection of stop codons in the RT gene resulted in the accumulation of replication-defective virus strains. Nevertheless, the observed release of defective viral particles in plasma was probably the result of viral protein complementation between replication-competent and replication-incompetent HIV-1 variants. The divergence in the proportion of RT(STOP) and RT(FL) variants as well as in the mutation's pattern to antiretroviral drug resistance between HIV-1 plasma RNA and PBMC proviral DNA, suggested that circulating lymphocytes expressing full-length RT might be negatively selected for by a specific T-cell response, possibly contributing to the slow progression to AIDS observed in this patient.
authors.affiliation: Molecular Virology Unit, Virology and Microbiology, Fondazione IRCCS Policlinico San Matteo, 27100 Pavia, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Paolucci
authors.forename: Roberto
authors.initials: R
authors.lastname: Gulminetti
authors.forename: Renato
authors.initials: R
authors.lastname: Maserati
authors.forename: Luca
authors.initials: L
authors.lastname: Dossena
authors.forename: Fausto
authors.initials: F
authors.lastname: Baldanti
mesh_terms: D000328:Adult; D000595:Amino Acid Sequence; D002478:Cells, Cultured; D018389:Codon, Nonsense; D004279:DNA, Viral / Q000235:genetics / Q000302:isolation & purification; D015658:HIV Infections / Q000821:virology*; D020276:HIV Long-Term Survivors; D054303:HIV Reverse Transcriptase / Q000172:deficiency* / Q000235:genetics; D015497:HIV-1 / Q000201:enzymology* / Q000235:genetics / Q000472:pathogenicity*; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000821:virology; D008297:Male; D008969:Molecular Sequence Data; D012367:RNA, Viral / Q000235:genetics / Q000302:isolation & purification; D017422:Sequence Analysis, DNA; D017384:Sequence Deletion; D014779:Virus Replication
chemical_list: D018389:Codon, Nonsense; D004279:DNA, Viral; D012367:RNA, Viral; C514824:reverse transcriptase, Human immunodeficiency virus 1; D054303:HIV Reverse Transcriptase