C. Soulié

Historical HIV-RNA resistance test results are more informative than proviral DNA genotyping in cases of suppressed or residual viraemia

BACKGROUND Resistance genotyping is often requested due to residual HIV viraemia or for treatment optimization, but may be unsuccessful if plasma RNA levels are too low or undetectable. Analyses of proviral HIV-DNA can provide information about the viral reservoir, because integrated DNA reflects both actively and latently infected cells. OBJECTIVES To determine whether proviral DNA is a potential relevant alternative to HIV-RNA for resistance genotyping in this context. METHODS The resistance mutations harboured by the proviral DNA were compared with the cumulative data for all plasma RNA genotypes previously obtained for the patient concerned. We also investigated whether various parameters, such as CD4 count, level of viraemia or drug pressure, affected the results. RESULTS We collected 134 and 141 DNA genotypes with 443 and 462 corresponding RNA sequences for the reverse transcriptase and protease genes, respectively. The mean rates of concordance between DNA and RNA genotypes were 46.7% for nucleoside reverse transcriptase inhibitors (NRTIs), 26.3% for non-NRTIs and 43.7% for protease inhibitors (PIs). Mixtures were detected for most DNA mutations. The rate of concordant PI mutations was significantly higher for patients taking PIs at the time of DNA genotyping (48% versus 26%; P=0.004). The other factors studied had no impact. CONCLUSIONS In the context of low or undetectable viraemia, it is difficult to reach the archived mutated DNA. Classical RNA genotyping during previous periods of virological failure remains the gold standard for documenting resistance mutations and for the monitoring of future treatments.

Prevalence of pre-existing resistance-associated mutations to rilpivirine, emtricitabine and tenofovir in antiretroviral-naive patients infected with B and non-B subtype HIV-1 viruses

OBJECTIVES The prevalence of rilpivirine, emtricitabine and tenofovir resistance-associated mutations (RAMs), described in vitro and in vivo, was determined in antiretroviral-naive patients. PATIENTS AND METHODS From 2008 to 2011, 1729 treatment-naive patients were tested for resistance by bulk sequencing. We studied the primary rilpivirine RAMs (K101E/P, E138A/G/K/Q/R, V179L, Y181C/I/V, H221Y, F227C and M230I/L) and other potential rilpivirine-associated mutations (V90I, L100I, K101T, E138S, V179D/I, Y188L, V189I, G190A/E/S and M230V). We also studied the M184V/I and K65R mutations for emtricitabine and tenofovir, respectively. RESULTS Among 1729 sequences, half of patients had B-subtype viruses and the other half non-B (with 26.7% CRF02, n=461). Primary rilpivirine RAMs were infrequent (4.6%, n=79) and the most prevalent were E138A (3%, n=52), E138K, (0.3%, n=5), H221Y (0.3%, n=5), E138G (0.2%, n=4) and Y181C (0.2%, n=4). The frequency of the primary rilpivirine RAMs was similar between B and non-B subtypes. The other potential rilpivirine-associated mutations that were most prevalent were V179I (8.4%, n=145), V90I (3.8%, n=65) and V189I (2.3%, n=40). The common V179I, V189I and V90I polymorphisms have not been associated with virological failure in Phase 3 clinical studies. By the ANRS algorithm, 4.9% (n=84) of samples were resistant to rilpivirine, 3.7% (n=32) of B-subtype viruses versus 6% (n=52) of non-B-subtype viruses (P=0.02, χ(2) test). The prevalence of K65R and M184I/V was 0.06% (1/1729) and 1% (18/1729), respectively. The prevalence of K103N was 2% (35/1729). CONCLUSIONS The prevalence of rilpivirine, emtricitabine and tenofovir resistance mutations was very low in antiretroviral-naive patients. The prevalence of resistance to rilpivirine (4.9%, n=84) was not statistically different from the prevalence of efavirenz and nevirapine resistance in our population.

Maraviroc plus raltegravir failed to maintain virological suppression in HIV-infected patients with lipohypertrophy: results from the ROCnRAL ANRS 157 study

BACKGROUND Novel nucleoside reverse transcriptase inhibitor- and protease inhibitor-sparing strategies are needed in long-term-treated patients with lipohypertrophy. Given their potency and their excellent metabolic profile, maraviroc and raltegravir appear to be good candidates for such an approach. METHODS This single-arm study enrolled lipohypertrophic HIV-infected patients with suppressed viraemia and an R5 tropic virus in HIV DNA; they switched from suppressive antiretroviral treatment to maraviroc plus raltegravir. The primary endpoint was the proportion of patients with treatment success at week 24, defined as no virological failure or treatment discontinuation. To ensure a success rate of at least 80%, a maximum of 10 failures were allowed for 90 patients enrolled. ClinicalTrials.gov: NCT01420523. RESULTS A total of 44 patients were enrolled; their median age was 55 years, median nadir CD4 cell count was 210 cells/mm(3), median time on antiretroviral treatment was 15 years and median duration of viral suppression was 5.2 years. Seven patients failed maraviroc/raltegravir therapy: five had virological failure and two discontinued treatment due to serious adverse events (one had hepatitis B virus reactivation and one had hypersensitivity syndrome). At failure, raltegravir resistance mutations were detected in 3/5 patients and CXCR4 tropic virus in 2/5. Upon DSMB recommendation, the study was prematurely discontinued on 3 September 2012. Lipid profile and bone mineral density improved with a decrease from baseline values in total cholesterol (-0.56 ± 0.95 mmol/L; P = 0.001), low-density lipoprotein cholesterol (-0.31 ± 0.81 mmol/L; P = 0.039) and triglycerides (-0.59 ± 1.12 mmol/L; P = 0.001) and an increase in total hip bone mineral density (+0.9 ± 1.5%; P = 0.013) CONCLUSIONS: In long-term-experienced patients, maraviroc/raltegravir therapy lacks virological robustness despite a benefit in lipid profile and bone density.

Raltegravir Concentrations in the Genital Tract of HIV-1-Infected Women Treated with a Raltegravir-Containing Regimen (DIVA 01 Study)

ABSTRACT We studied the penetration of raltegravir and HIV shedding in the genital tract among 14 HIV-1-infected women receiving a raltegravir-containing regimen who had <40 copies/ml blood plasma (BP) HIV RNA. None of the cervicovaginal fluid (CVF) samples showed detectable HIV RNA. Median raltegravir concentrations were 235 ng/ml in BP and 93 ng/ml in CVF, with a CVF/BP ratio of approximately 2.3. This good penetration of raltegravir may contribute to the control of viral replication in the female genital tract.

Factors associated with a low HIV reservoir in patients with prolonged suppressive antiretroviral therapy

OBJECTIVES The relevance of low-level HIV DNA in patients who have undergone prolonged therapy is not well understood. The objective of this study was to determine factors that influence the establishment of low-level HIV DNA in long-term treated patients (excluding treatment since acute infection). METHODS This was a cross-sectional study involving 243 patients receiving highly active antiretroviral therapy (HAART) for ≥6 months (median: 9 years of treatment) with plasma HIV RNA <50 copies/mL at the study timepoint, for whom total DNA measurements were performed. Patients treated since early acute infection or receiving cancer chemotherapeutic/immunosuppressive agents were excluded from the study. RESULTS Overall, the median HIV DNA was 372 copies/10(6) peripheral blood mononuclear cells (PBMCs). Forty-seven patients had levels of HIV DNA below the limit of detection and 58 patients had low-level HIV DNA (<100 copies/10(6) PBMCs). In multivariate analysis, a low total HIV DNA in HAART-treated patients was clearly associated with a low HIV RNA pre-therapeutic viral load (P < 0.0001), regardless of the cut-off used. CONCLUSIONS These results may be helpful to identify candidates for future trials aiming at a functional cure of HIV infection, since low total HIV DNA levels will most likely be a prerequisite of successful immunological control of HIV replication.

Synthesis of apolipoprotein E (ApoE) mRNA by human neuronal- type SK N SH-SY 5Y cells and its regulation by nerve growth factor and ApoE

By in situ hybridization, we show the ability of human neuroblastoma SY 5Y cells to synthesize apolipoprotein E (apoE) mRNA. This synthesis varied during cell NGF-differentiation: the mRNA level decreased during the first 4 days of NGF treatment (NGF 4 days) and then increased during the 3 following days (NGF 7 days). Furthermore, a treatment of 4-day NGF differentiated cells with exogenous apoE during 3 additional days induced a clear decrease in apoE mRNA synthesis when compared with control cells. This effect was more or less pronounced according to the apoE tested variants: apoE4 was more efficient to decrease the apoE mRNA synthesis as compared with the control cells than apoE3 which was itself more efficient than apoE2. These results suggest that apoE mRNA synthesis in human neuronal-type cells could be regulated by different mechanisms such as those induced by NGF- and apoE-treatments.

Improved V3 genotyping with duplicate PCR amplification for determining HIV-1 tropism

OBJECTIVES To determine whether genotyping of HIV-1 by duplicate PCR amplification of the region encoding the V3 loop is more sensitive than single PCR for detecting CXCR4-using viruses. PATIENTS AND METHODS The V3 genotypes of the HIV-1 infecting 152 patients enrolled in the multicentre GenoTropism ANRS study were determined by all the participating laboratories using a single PCR and V3 bulk sequencing. In parallel, one laboratory determined the V3 genotype using duplicate PCR and bulk sequencing of pooled amplicons. HIV tropism was predicted with the geno2pheno10 algorithm. The phenotypes of all samples were determined with the Trofile assay and the Toulouse tropism test (TTT) recombinant virus assay. RESULTS Geno2pheno10 was 56.8% sensitive and 75.9% specific when compared with the Trofile assay for detecting CXCR4-using viruses after a single PCR. Duplicate amplification and bulk sequencing of the pooled PCR amplicons increased the sensitivity to 68.2% and specificity to 79.6%. Geno2pheno10 was 64.1% sensitive and 77.0% specific when compared with the TTT assay for detecting CXCR4-using viruses after a single PCR. Duplicate amplification and sequencing of the pooled PCR amplicons increased sensitivity to 76.9% and specificity to 80.5%. CONCLUSIONS The genotypic determination of HIV-1 tropism can be improved by duplicate amplifications and sequencing the pooled PCR products. This is a good compromise between improved sensitivity and reasonable cost for the genotype-based determination of tropism.

Dephosphorylation studies of SKNSH-SY 5Y cell Tau proteins by endogenous phosphatase activity☆

Recent data have shown that the microtubule-associated Tau proteins are phosphorylated but to a lesser extent than PHF-Tau proteins which are the major components of Alzheimers disease paired helical filaments. These normal Tau proteins are highly sensitive to the endogenous phosphatase activity during post-mortem delay. In order to understand the basic equilibrium between phosphatase and kinase activities, phosphorylation and dephosphorylation mechanisms of Tau proteins were studied in neuroblastoma cells. The present results demonstrate that an endogenous phosphatase activity is present and directed on Tau proteins in the SKNSH-SY 5Y cell extracts. Interestingly, the okadaic acid-induced hyperphosphorylated Tau proteins are more resistant to the phosphatase activity than the control Tau proteins. Our data emphasize the value of this in vitro cellular model for the study of biological conditions that control Tau protein phosphorylation levels.

Etravirine concentrations in the cervicovaginal compartment in HIV-1-infected women receiving etravirine-containing antiretroviral therapy: DIVA 02 study.

ABSTRACT We studied the penetration of etravirine and HIV shedding in the genital tract among 12 HIV-1-infected women receiving an etravirine-containing regimen who had <40 copies/ml blood plasma (BP) HIV RNA. None of the cervicovaginal fluid (CVF) samples showed detectable HIV RNA. Median etravirine concentrations were 663 ng/ml in BP and 857 ng/ml in CVF, with a CVF/BP etravirine ratio of approximately 1.2. This good penetration of etravirine may contribute to the control of viral replication in the female genital tract.

Apolipoprotein E and Tau phosphorylation in human neuroblastoma cells.

Phosphorylation is the major post-translational modification of Tau proteins and it plays an important role in Tau biological functions. Hyperphosphorylation of these proteins occurs during neurodegenerative disorders such as Alzheimers disease. It was hypothesized that some variants of apolipoprotein E (apo E) may have a protective effect against the normal or pathological phosphorylation of Tau proteins. We have recently shown that apo E synthesis occurs in human SY 5Y and Kelly neuroblastoma cell lines which express different isoforms (E3 for SY 5Y; E3 and E4 for Kelly) [Dupont-Wallois, L., Soulié, C., Sergeant, N., Wavrant-de Wrieze, F., Chartier-Harlin, M.C., Delacourte, A. and Caillet-Boudin, M.L., Neurobiol. Dis., 4 (1997) 356-364]. Therefore, this cellular model makes it possible to study the differential influence, if any, of apo E3 and E4 on Tau phosphorylation. Using a large panel of Tau phosphorylation-dependent antibodies, we were not able to detect a significant difference in Tau immunoreactivity linked to the different apo E genotypes, even when the hyperphosphorylation of Tau proteins was induced by treating cells with Okadaic acid (OA), an inhibitor of phosphatase 1 and 2A proteins. Thus, a difference in apo E isoforms had no dramatic effect upon Tau phosphorylation in native or OA treated cells.