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Objectives: HIV-1 V3 quasispecies was analyzed by ultra-deep pyrosequencing, in early HIV-infected patients, to assess possible correlations between quasispecies diversity, frequency of variants predicted to use CXCR4 and need for early antiretroviral treatment. Methods: Twenty patients were retrospectively enrolled: 10 patients (group A) required HAART within 6 months from seroconversion and 10 (group B) remained free of therapy during this period. V3 quasispecies was assessed on plasma viral RNA and in peripheral blood mononuclear cell-associated proviral DNA. Prediction of coreceptor usage was performed by position-specific score matrix analysis. Results: Variants predicted to use CXCR4 were detected (frequency >0.3%) in the plasma of 50% of early infected patients (60% from group A and 40% from group B). Intrapatient frequency of these variants was highly variable (0.3-56.3%). A positive correlation was observed between the proportion of X4 variants and intrapatient quasispecies diversity. Quasispecies diversity and absolute numbers of X4 variants were significantly higher in patients from group A. The analysis of proviral DNA quasispecies, performed in a subgroup of five patients, showed that X4 variants were not detected in patients with RNA frequency below 0.3%, and detected at 3.6% in the patient with 56.3% of X4 plasma variants. Conclusion: Our findings show that X4 variants may be frequently found, at variable intrapatient frequency, in early infected patients, and that quasispecies diversity and absolute numbers of X4 variants are significantly higher in patients undergoing early antiretroviral treatment. Further studies are mandatory to explore the clinical relevance of X4 variants present during early infection with respect to clinical progression and possible therapeutic implications.

Objective gammadelta T cells bearing the Vgamma9Vdelta2 T-cell receptor exert many antiviral effector functions in humans, including release of anti-HIV factors and direct cytotoxicity against virus-infected cells. Moreover, they are known to activate dendritic cells, improving antigen presentation function. After HIV infection, Vgamma9Vdelta2 T-cell number and reactivity are rapidly affected and they decrease upon disease progression. Bisphosphonate drugs such as zoledronic acid (Zol), used to treat bone diseases, have been shown to induce in vivo, in combination with interleukin-2, Vgamma9Vdelta2 T-cells' activation. The aim of this work was to verify whether the administration of Zol in combination with interleukin-2 in HIV-infected patients might improve Vgamma9Vdelta2 T-cell function, including immune adjuvancy mediated by gammadelta-dendritic cell cross-talk. Design and methods In HIV patients naive to antiretroviral therapy, we analyzed the effect of combined Zol and interleukin-2 treatment, in comparison to Zol alone, on Vgamma9Vdelta2 T-cell number, maturation and function, on dendritic cell activation and on HIV-specific CD8 T-cell response. Results Zol and interleukin-2-combined treatment induced in-vivo Vgamma9Vdelta2 T-cell expansion and maturation. Paralleling Vgamma9Vdelta2 T-cell activation, increased dendritic cell maturation and HIV-specific CD8 T-cell responses were found. Conclusion The specific modulation of Vgamma9Vdelta2 T-cell number and responsiveness after HIV infection may be at least transiently restored in vivo by Zol and interleukin-2 treatment. In this way, the immune effector mechanisms, secondary to Vgamma9Vdelta2 T-cell activation, were improved, suggesting a possible adjuvancy role of Zol and interleukin-2 treatment in restoring innate and specific competence in HIV-infected persons.

A rebound in the plasma and seminal viral load was detected in 12 patients after the interruption of effective highly active antiretroviral therapy. The viral rebound was generally higher in plasma, although the highest level observed during interruption was higher in semen in two patients. The reintroduction of therapy was followed by an overall decrease in HIV-RNA in plasma and semen. One to 2 months after restarting treatment, four out of seven patients showed undetectable HIV-RNA in semen.

Objective: The influence of structured treatment interruption on effector/memory CD8 T cell dynamics was analysed in chronic HIV-infected patients showing a rapid or delayed viral rebound. Design: Structured treatment interruption consisted of at least one month of discontinuation, followed by highly active antiretroviral therapy (HAART) resumption. Two groups of HIV structured treatment interruption patients were selected on the basis of plasma viral HIV-RNA value (> 30 000 copies/ml, branched DNA): group A (n = 14), patients with a rapid viral rebound (within one month) and group B (n = 6), patients with a delayed or no viral rebound (after a minimum of 4 months). Methods: A clinical and immunological follow-up was performed at HAART suspension (t 0), one month from suspension (t 1), at HAART resumption (t 2), and 30 days from resumption (t 3). Results: A sustained viral rebound was observed in group A patients, showing a rapid expansion of circulating CD8 T lymphocytes. In this group, the frequencies of CD8 T cells releasing IFN-y after mitogen-induced or Gag-specific stimulation were highly increased after HAART discontinuation. Nevertheless, these CD8 T lymphocytes were mainly composed of pre-terminally differentiated cytotoxic T lymphocytes (CTL) expressing a CCR7 - CD27 +/- CD45RA - phenotype and a reduced amount of perforin. In contrast, group B patients showed no significant changes in immunological parameters during a prolonged drug-free period. Conclusion: These data indicate that monitoring CD8 T cell dynamics during structured treatment interruption could be clinically relevant, and new therapeutic strategies should aim qualitatively to restore CTL effector functions.