Mitochondrial Bioenergetic Alterations in Mouse Neuroblastoma Cells Infected with Sindbis Virus: Implications to Viral Replication and Neuronal Death

The metabolic resources crucial for viral replication are provided by the host. Details of the mechanisms by which viruses interact with host metabolism, altering and recruiting high free-energy molecules for their own replication, remain unknown. Sindbis virus, the prototype of and most widespread alphavirus, causes outbreaks of arthritis in humans and serves as a model for the study of the pathogenesis of neurological diseases induced by alphaviruses in mice. In this work, respirometric analysis was used to evaluate the effects of Sindbis virus infection on mitochondrial bioenergetics of a mouse neuroblastoma cell lineage, Neuro 2a. The modulation of mitochondrial functions affected cellular ATP content and this was synchronous with Sindbis virus replication cycle and cell death. At 15 h, irrespective of effects on cell viability, viral replication induced a decrease in oxygen consumption uncoupled to ATP synthesis and a 36% decrease in maximum uncoupled respiration, which led to an increase of 30% in the fraction of oxygen consumption used for ATP synthesis. Decreased proton leak associated to complex I respiration contributed to the apparent improvement of mitochondrial function. Cellular ATP content was not affected by infection. After 24 h, mitochondria dysfunction was clearly observed as maximum uncoupled respiration reduced 65%, along with a decrease in the fraction of oxygen consumption used for ATP synthesis. Suppressed respiration driven by complexes I- and II-related substrates seemed to play a role in mitochondrial dysfunction. Despite the increase in glucose uptake and glycolytic flux, these changes were followed by a 30% decrease in ATP content and neuronal death. Taken together, mitochondrial bioenergetics is modulated during Sindbis virus infection in such a way as to favor ATP synthesis required to support active viral replication. These early changes in metabolism of Neuro 2a cells may form the molecular basis of neuronal dysfunction and Sindbis virus-induced encephalitis

Impact of Insertions in the HIV-1 P6 Ptapp Region on the Virological Response to Amprenavir

We evaluated the impact of genetic changes within p6Gag gene on the virological response (VR, mean decrease in plasma viral load at week 12) to unboosted amprenavir (APV). Gag-protease fragments, including gag p2, p7, p1, p6 regions and whole protease (PR) were sequenced from baseline plasma specimens of 84 highly pre-treated but APV-naive patients included in the NARVAL (ANRS 088) trial. The correlation between baseline p6Gag polymorphism, PR mutations, baseline characteristics and VR to APV was analysed in univariate analysis. Insertions (P459Ins) within p6 protein, leading to partial or complete duplication of the PTAPP motif, were significantly associated with a decreased VR (P459Ins versus wild-type; –0.3 ±0.8 vs –1.1 ±1.2 log copies/ml, P=0.007) and were more frequent when the V82A/F/T/S PR mutation was present ( P=0.020). In multivariate analysis, after adjustment on the predictive factors of the VR in the NARVAL trial and on the PR mutations linked with response, there was a strong trend to an association ( P=0.058) between the presence of P459Ins and an altered VR. In conclusion, these results suggest that insertions in the p6 region of HIV-1 gag gene may affect the VR, in highly pre-treated patients receiving an unboosted APV-containing regimen. </jats:p

No increased risk of Kaposi sarcoma relapse in patients with controlled HIV‐1 infection after switching protease inhibitor‐based antiretroviral therapy

International audienceObjectives: Our aim was to assess if switching from a protease inhibitors (PI)-based regimen to a PI-free one is associated with an increased risk of Kaposi Sarcoma (KS) relapse among patients living with HIV (PLHIV) with history of KS and controlled HIV replication.Methods: In a retrospective analysis of the prospectively collected Dat'AIDS database we selected patients who both had a past KS history and a HIV-1 viral load below 200 copies/mL while being PI-treated. We searched for KS relapses while persistent virological success was maintained for at least 6 months, whether patients kept taking the PI, or switched to PI-free regimen.Results: Among the 216 patients with past KS event and a history of HIV-1 infection efficiently treated by a PI-based regimen, 148 patients (68.5%) later switched to a PI-sparing regimen. Their baseline characteristics were not different from non-switching patients. We described 7 cases of relapse (3.2% of the 216 patients). Five cases of relapse occurred in switching patients (3.4%). The remaining two relapses occurred in PI-treated patients (2.9%). At KS relapse, CD4 cell count was 459 cells/μL (range 225-560) for switching patients, compared with 362 and 136 cells/μL for the other two patients.Conclusions: In this large cohort of PLHIV with a history of KS and ART-controlled HIV replication, KS relapses were described in 3.2% of the patients, and were not more frequent when a PI-containing ART regimen has been switched to a PI-free regimen. Our results do not support a specific effect of PI on KS

No increased risk of Kaposi sarcoma relapse in patients with controlled HIV‐1 infection after switching protease inhibitor‐based antiretroviral therapy

International audienceObjectives: Our aim was to assess if switching from a protease inhibitors (PI)-based regimen to a PI-free one is associated with an increased risk of Kaposi Sarcoma (KS) relapse among patients living with HIV (PLHIV) with history of KS and controlled HIV replication.Methods: In a retrospective analysis of the prospectively collected Dat'AIDS database we selected patients who both had a past KS history and a HIV-1 viral load below 200 copies/mL while being PI-treated. We searched for KS relapses while persistent virological success was maintained for at least 6 months, whether patients kept taking the PI, or switched to PI-free regimen.Results: Among the 216 patients with past KS event and a history of HIV-1 infection efficiently treated by a PI-based regimen, 148 patients (68.5%) later switched to a PI-sparing regimen. Their baseline characteristics were not different from non-switching patients. We described 7 cases of relapse (3.2% of the 216 patients). Five cases of relapse occurred in switching patients (3.4%). The remaining two relapses occurred in PI-treated patients (2.9%). At KS relapse, CD4 cell count was 459 cells/μL (range 225-560) for switching patients, compared with 362 and 136 cells/μL for the other two patients.Conclusions: In this large cohort of PLHIV with a history of KS and ART-controlled HIV replication, KS relapses were described in 3.2% of the patients, and were not more frequent when a PI-containing ART regimen has been switched to a PI-free regimen. Our results do not support a specific effect of PI on KS