The persistence of latently infected cells in patients under combinatory antiretroviral therapy (cART) is a major hurdle to HIV-1 eradication. Strategies to purge these reservoirs are needed and ...activation of viral gene expression in latently infected cells is one promising strategy. Bromodomain and Extraterminal (BET) bromodomain inhibitors (BETi) are compounds able to reactivate latent proviruses in a positive transcription elongation factor b (P-TEFb)-dependent manner. In this study, we tested the reactivation potential of protein kinase C (PKC) agonists (prostratin, bryostatin-1 and ingenol-B), which are known to activate NF-κB signaling pathway as well as P-TEFb, used alone or in combination with P-TEFb-releasing agents (HMBA and BETi (JQ1, I-BET, I-BET151)). Using in vitro HIV-1 post-integration latency model cell lines of T-lymphoid and myeloid lineages, we demonstrated that PKC agonists and P-TEFb-releasing agents alone acted as potent latency-reversing agents (LRAs) and that their combinations led to synergistic activation of HIV-1 expression at the viral mRNA and protein levels. Mechanistically, combined treatments led to higher activations of P-TEFb and NF-κB than the corresponding individual drug treatments. Importantly, we observed in ex vivo cultures of CD8+-depleted PBMCs from 35 cART-treated HIV-1+ aviremic patients that the percentage of reactivated cultures following combinatory bryostatin-1+JQ1 treatment was identical to the percentage observed with anti-CD3+anti-CD28 antibodies positive control stimulation. Remarkably, in ex vivo cultures of resting CD4+ T cells isolated from 15 HIV-1+ cART-treated aviremic patients, the combinations bryostatin-1+JQ1 and ingenol-B+JQ1 released infectious viruses to levels similar to that obtained with the positive control stimulation. The potent effects of these two combination treatments were already detected 24 hours post-stimulation. These results constitute the first demonstration of LRA combinations exhibiting such a potent effect and represent a proof-of-concept for the co-administration of two different types of LRAs as a potential strategy to reduce the size of the latent HIV-1 reservoirs.
The persistence of transcriptionally silent but replication-competent HIV-1 reservoirs in Highly Active Anti-Retroviral Therapy (HAART)-treated infected individuals, represents a major hurdle to ...virus eradication. Activation of HIV-1 gene expression in these cells together with an efficient HAART has been proposed as an adjuvant therapy aimed at decreasing the pool of latent viral reservoirs. Using the latently-infected U1 monocytic cell line and latently-infected J-Lat T-cell clones, we here demonstrated a strong synergistic activation of HIV-1 production by clinically used histone deacetylase inhibitors (HDACIs) combined with prostratin, a non-tumor-promoting nuclear factor (NF)- kappaB inducer. In J-Lat cells, we showed that this synergism was due, at least partially, to the synergistic recruitment of unresponsive cells into the expressing cell population. A combination of prostratin+HDACI synergistically activated the 5' Long Terminal Repeat (5'LTR) from HIV-1 Major group subtypes representing the most prevalent viral genetic forms, as shown by transient transfection reporter assays. Mechanistically, HDACIs increased prostratin-induced DNA-binding activity of nuclear NF-kappaB and degradation of cytoplasmic NF-kappaB inhibitor, IkappaBalpha . Moreover, the combined treatment prostratin+HDACI caused a more pronounced nucleosomal remodeling in the U1 viral promoter region than the treatments with the compounds alone. This more pronounced remodeling correlated with a synergistic reactivation of HIV-1 transcription following the combined treatment prostratin+HDACI, as demonstrated by measuring recruitment of RNA polymerase II to the 5'LTR and both initiated and elongated transcripts. The physiological relevance of the prostratin+HDACI synergism was shown in CD8(+)-depleted peripheral blood mononuclear cells from HAART-treated patients with undetectable viral load. Moreover, this combined treatment reactivated viral replication in resting CD4(+) T cells isolated from similar patients. Our results suggest that combinations of different kinds of proviral activators may have important implications for reducing the size of latent HIV-1 reservoirs in HAART-treated patients.
Background. The use of raltegravir in human immunodeficiency virus (HIV)–infected pregnant women is important in the prevention of mother-to-child HIV transmission, especially in circumstances when a ...rapid decline of HIV RNA load is warranted or when preferred antiretroviral agents cannot be used. Physiological changes during pregnancy can reduce antiretroviral drug exposure. We studied the effect of pregnancy on the pharmacokinetics of raltegravir and its safety and efficacy in HIV-infected pregnant women. Methods. An open-label, multicenter, phase 4 study in HIV-infected pregnant women receiving raltegravir 400 mg twice daily was performed (Pharmacokinetics of Newly Developed Antiretroviral Agents in HIV-Infected Pregnant Women Network). Steady-state pharmacokinetic profiles were obtained in the third trimester and postpartum along with cord and maternal delivery concentrations. Safety and virologic efficacy were evaluated. Results. Twenty-two patients were included, of which 68% started raltegravir during pregnancy. Approaching delivery, 86% of the patients had an undetectable viral load (<50 copies/mL). None of the children were HIV-infected. Exposure to raltegravir was highly variable. Overall area under the plasma concentration-time curve (AUC) and plasma concentration at 12 hours after intake (C12h) plasma concentrations in the third trimester were on average 29% and 36% lower, respectively, compared with postpartum: Geometric mean ratios (90% confidence interval) were 0.71 (.53–.96) for AUC0–12h and 0.64 (.34–1.22) for C12h. The median ratio of raltegravir cord to maternal blood was 1.21 (interquartile range, 1.02–2.17; n = 9). Conclusions. Raltegravir was well tolerated during pregnancy. The pharmacokinetics of raltegravir showed extensive variability. The observed mean decrease in exposure to raltegravir during third trimester compared to postpartum is not considered to be of clinical importance. Raltegravir can be used in standard dosages in HIV-infected pregnant women. Clinical Trials Registration. NCT00825929.
Reactivation of HIV gene expression in latently infected cells together with an efficient cART has been proposed as an adjuvant therapy aimed at eliminating/decreasing the reservoir size. Results ...from HIV clinical trials using deacetylase inhibitors (HDACIs) question the efficiency of these latency‐reversing agents (LRAs) used alone and underline the need to evaluate other LRAs in combination with HDACIs. Here, we evaluated the therapeutic potential of a demethylating agent (5‐AzadC) in combination with clinically tolerable HDACIs in reactivating HIV‐1 from latency first in vitro and next ex vivo. We showed that a sequential treatment with 5‐AzadC and HDACIs was more effective than the corresponding simultaneous treatment both in vitro and ex vivo. Interestingly, only two of the sequential LRA combinatory treatments tested induced HIV‐1 particle recovery in a higher manner than the drugs alone ex vivo and at concentrations lower than the human tolerable plasmatic concentrations. Taken together, our data reveal the benefit of using combinations of 5‐AzadC with an HDACI and, for the first time, the importance of treatment time schedule for LRA combinations in order to reactivate HIV.
Synopsis
Sequential administration of latency‐reversing agents (LRAs), namely deacetylase inhibitors (HDACIs) and demethylating agents, together with an efficient cART, could represent an adjuvant anti‐HIV‐1 therapy to induce viral production and possibly reduce the size of latent HIV‐1 reservoirs.
A sequential treatment with 5‐AzadC and HDACIs is more effective both in vitro and ex vivo at inducing HIV gene expression than the corresponding simultaneous treatments, highlighting for the first time the importance of treatment schedule for LRAs combinations.
Combining 5‐AzadC + panobinostat and 5‐AzadC + romidepsin show reactivation potentials at concentrations lower than the human tolerable plasmatic concentrations.
These findings are valuable for designing future anti‐latency therapeutic strategies and thereby constitute a step forward in achieving HIV remission.
Sequential administration of latency‐reversing agents (LRAs), namely deacetylase inhibitors (HDACIs) and demethylating agents, together with an efficient cART, could represent an adjuvant anti‐HIV‐1 therapy to induce viral production and possibly reduce the size of latent HIV‐1 reservoirs.
Abacavir is a nucleoside reverse transcriptase inhibitor used as part of combination antiretroviral therapy in HIV-1-infected patients. Because this drug can cause a hypersensitivity reaction that is ...correlated with the presence of the HLA-B*57:01 allotype, screening for the presence of HLA-B*57:01 is recommended before abacavir initiation. Different genetic assays have been developed for HLA-B*57:01 screening, each with specific sensitivity, turnaround time and assay costs. Here, a new real-time PCR (qPCR) based analysis is described and compared to sequence specific primer PCR with capillary electrophoresis (SSP PCR CE) on 149 patient-derived samples, using sequence specific oligonucleotide hybridization combined with high resolution SSP PCR as gold standard. In addition to these PCR based methods, a complementary approach was developed using flow cytometry with an HLA-B17 specific monoclonal antibody as a pre-screening assay to diminish the number of samples for genetic testing. All three assays had a maximum sensitivity of >99. However, differences in specificity were recorded, i.e. 84.3%, 97.2% and >99% for flow cytometry, qPCR and SSP PCR CE respectively. Our data indicate that the most specific and sensitive of the compared methods is the SSP PCR CE. Flow cytometry pre-screening can substantially decrease the number of genetic tests for HLA-B*57:01 typing in a clinical setting.
HIV-1 infected patients for whom standard gp160 phenotypic tropism testing failed are currently excluded from co-receptor antagonist treatment. To provide patients with maximal treatment options, ...massively parallel sequencing of the envelope V3 domain, in combination with tropism prediction tools, was evaluated as an alternative tropism determination strategy. Plasma samples from twelve HIV-1 infected individuals with failing phenotyping results were available. The samples were submitted to massive parallel sequencing and to confirmatory recombinant phenotyping using a fraction of the gp120 domain.
A cut-off for sequence reads interpretation of 5 to10 times the sequencing error rate (0.2%) was implemented. On average, each sample contained 7 different V3 haplotypes. V3 haplotypes were submitted to tropism prediction algorithms, and 4/14 samples returned with presence of a dual/mixed (D/M) tropic virus, respectively at 3%, 10%, 11%, and 95% of the viral quasispecies. V3 tropism prediction was confirmed by gp120 phenotyping, except for two out of 4 D/M predicted viruses (with 3 and 95%) which were phenotypically R5-tropic. In the first case, the result was discordant due to the limit of detection for the phenotyping technology, while in the latter case the prediction algorithms were not computing the viral tropism correctly.
Although only demonstrated on a limited set of samples, the potential of the combined use of "deep sequencing + prediction algorithms" in cases where routine gp160 phenotype testing cannot be employed was illustrated. While good concordance was observed between gp120 phenotyping and prediction of R5-tropic virus, the results suggest that accurate prediction of X4-tropic virus would require further algorithm development.
Reactivation of HIV-1 expression in persistent reservoirs together with an efficient HAART has been proposed as an adjuvant therapy aimed at reaching a functional cure for HIV. Previously, H3K9 ...methylation was shown to play a major role in chromatin-mediated repression of the HIV-1 promoter. Here, we evaluated the therapeutic potential of histone methyltransferase inhibitors (HMTIs) in reactivating HIV-1 from latency.
We evaluated the reactivation potential of two specific HMTIs (chaetocin and BIX-01294, two specific inhibitors of Suv39H1 and G9a, respectively) in ex-vivo cultures of resting CD4 T cells isolated from HIV-1-infected HAART-treated individuals.
We measured HIV-1 recovery in ex-vivo cultures treated with an HMTI alone or in combination with other HIV-1 inducers (in absence of IL-2 and of allogenic stimulation) of CD8-depleted peripheral blood mononuclear cells (PBMCs) or of resting CD4 T cells isolated from 67 HIV-infected, HAART-treated patients with undetectable viral load.
We demonstrated, for the first time, that chaetocin induced HIV-1 recovery in 50% of CD8-depleted PBMCs cultures and in 86% of resting CD4 T-cell cultures isolated from HIV-1-infected, HAART-treated patients, whereas BIX-01294 reactivated HIV-1 expression in 80% of resting CD4 T-cell cultures isolated from similar patients. Moreover, we showed that combinatory treatments including one HMTI and either the histone deacetylase inhibitor suberoylanilide hydroxamic acid or the non-tumor-promoting NF-κB inducer prostratin had a higher reactivation potential than these compounds alone.
Our results constitute a proof-of-concept for the therapeutic potential of HMTIs in strategies aiming at reducing the pool of latent reservoirs in HIV-infected, HAART-treated patient.
To better understand risk factors for the sexual transmission of hepatitis C viral (HCV) infection among men who have sex with men (MSM).
Case-control study among HIV-infected MSM, attending AIDS ...Reference Centers in Belgium.
Cases were HIV-infected MSM who were diagnosed with HCV between January 2010 and December 2013. For each case, 2 controls were randomly selected among the HIV-positive MSM who tested negative for HCV around the same time as the cases were identified. Consenting participants were interviewed with a questionnaire on risk factors. Medical records were abstracted to document past episodes of sexually transmitted infections (STIs). Associations between HCV infection and risk factors were explored using bivariate analysis followed by multiple logistic regression analysis.
A total of 52 cases and 90 controls were recruited. In multivariate analysis, douching before anal intercourse adjusted odds ratio (AOR) = 9.84, 95% CI: 2.26 to 42.78, fisting (AOR = 3.54, 95% CI: 1.31 to 9.57), having intercourse with HIV-positive men (AOR = 5.51, 95% CI: 1.87 to 16.20), and a documented gonorrhoea or chlamydial infection in the year before inclusion in the study (AOR = 4.50, 95% CI: 1.11 to 18.31) were independently associated with incident HCV infection.
Our study confirmed fisting and suffering from other STIs as risk factors for HCV and suggested an increased risk of HCV associated with serosorting. Furthermore, we identified anal douching as being associated with HCV infection. The role that douching plays in the acquisition of HCV infection and other STIs requires further research, as well as the effect of serosorting on STI transmission.
To describe the pharmacokinetics of tenofovir and emtricitabine in the third trimester of pregnant HIV-infected women and at postpartum.
A nonrandomized, open-label, multicentre phase IV study in ...HIV-infected pregnant women recruited from HIV treatment centres in Europe.
HIV-infected pregnant women treated with the nucleotide/nucleoside analogue reverse transcriptase inhibitors (NRTIs) tenofovir disoproxil fumarate (TDF 300 mg; equivalent to 245 mg tenofovir disoproxil) and/or emtricitabine (FTC 200 mg) were included in the study. Twenty-four-hour pharmacokinetic curves were recorded in the third trimester (preferably week 33) and postpartum (preferably week 4-6). Collection of a cord blood sample and maternal sample at delivery was optional. Pharmacokinetic parameters were calculated using WinNonlin software version 5.3. Statistical analysis was conducted using SPSS version 16.0.
Thirty-four women were included in the analysis. Geometric mean ratios of third trimester vs. postpartum 90% confidence interval (CI) were 0.77 (0.71-0.83) for TDF area under the curve (AUC0-24 h); 0.81 (0.68-0.96) for TDF Cmax and 0.79 (0.70-0.90) for TDF C24 h and 0.75 (0.68-0.82) for FTC AUC0-24 h; and 0.87 (0.77-0.99) for FTC Cmax and 0.77 (0.52-1.12) for FTC C24 h. The viral load close to delivery was less than 200 copies/ml in all but one patient, the average gestational age at delivery was 38 weeks. All children were tested HIV-negative and no congenital abnormalities were reported.
Although pharmacokinetic exposure of the NRTIs TDF and FTC during pregnancy is approximately 25% lower, this was not associated with virological failure in this study and did not result in mother-to-child transmission.
Akt signaling plays a central role in many biological processes, which are key players in human immunodeficiency virus 1 (HIV-1) pathogenesis. We found that Akt interacts with HIV-1 Nef protein. In ...primary T cells treated with exogenous Nef or acutely infected with Nef-expressing HIV-1 in vitro, Akt became phosphorylated on serine(473) and threonine(308). In vitro, Akt activation mediated by Nef in T-cells was blocked by HIV protease inhibitors (PI), but not by reverse transcriptase inhibitors (RTI). Ex vivo, we found that the Akt pathway is hyperactivated in peripheral blood lymphocytes (PBLs) from cART naïve HIV-1-infected patients. PBLs isolated from PI-treated patients, but not from RTI-treated patients, exhibited decreased Akt activation, T-cell proliferation and IL-2 production. We found that PI but not RTI can block HIV-1 reactivation in latently infected J-Lat lymphoid cells stimulated with various stimuli. Using luciferase measurement, we further confirmed that Nef-mediated reactivation of HIV-1 from latency in 1G5 cells was blocked by PI parallel to decreased Akt activation. Our results indicate that PI-mediated blockade of Akt activation could impact the HIV-1 reservoir and support the need to further assess the therapeutic use of HIV-1 PI in order to curtail latently infected cells in HIV-1-infected patients.
PDF
