Kabamba Kabeya - Academia.edu (original) (raw)

Papers by Kabamba Kabeya

Research paper thumbnail of Tuning of AKT-pathway by Nef and its blockade by protease inhibitors results in limited recovery in latently HIV infected T-cell line

Scientific reports, Jan 14, 2016

Akt signaling plays a central role in many biological processes, which are key players in human i... more 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...

Research paper thumbnail of Sequential treatment with 5-aza-2'-deoxycytidine and deacetylase inhibitors reactivates HIV-1

EMBO molecular medicine, Jan 17, 2015

Reactivation of HIV gene expression in latently infected cells together with an efficient cART ha... more 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. Tak...

Research paper thumbnail of An In-Depth Comparison of Latency-Reversing Agent Combinations in Various In Vitro and Ex Vivo HIV-1 Latency Models Identified Bryostatin-1+JQ1 and Ingenol-B+JQ1 to Potently Reactivate Viral Gene Expression

PLOS Pathogens, 2015

The persistence of latently infected cells in patients under combinatory antiretroviral therapy (... more 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 latencyreversing agents (LRAs) and that their combinations led to synergistic activation of HIV-1 PLOS Pathogens | 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.

Research paper thumbnail of Risk Factors for HCV Acquisition Among HIV-Positive MSM in Belgium

JAIDS Journal of Acquired Immune Deficiency Syndromes, 2015

Objective: To better understand risk factors for the sexual transmission of hepatitis C (HCV) inf... more Objective: To better understand risk factors for the sexual transmission of hepatitis C (HCV) infection among MSM. Design: Case control study among HIV infected MSM, attending AIDS Reference Centers in Belgium. Methods: Cases were HIV infected MSM who were diagnosed with HCV between January 2010 and December 2013. For each case two controls were randomly selected from 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. Associations between HCV infection and risk factors were explored using bivariate analysis followed by multiple logistic regression analysis.

Research paper thumbnail of Synergistic Activation of HIV-1 Expression by Deacetylase Inhibitors and Prostratin: Implications for Treatment of Latent Infection

PLoS ONE, 2009

The persistence of transcriptionally silent but replication-competent HIV-1 reservoirs in Highly ... more 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)-kB 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 59 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-kB and degradation of cytoplasmic NF-kB inhibitor, IkBa . 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.

Research paper thumbnail of Tuning of AKT-pathway by Nef and its blockade by protease inhibitors results in limited recovery in latently HIV infected T-cell line

Akt signaling plays a central role in many biological processes, which are key players in human i... more 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.

Research paper thumbnail of Sequential treatment with 5-aza-2'-deoxycytidine and deacetylase inhibitors reactivates HIV-1

EMBO molecular medicine, Jan 17, 2015

Reactivation of HIV gene expression in latently infected cells together with an efficient cART ha... more 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. Tak...

Research paper thumbnail of An In-Depth Comparison of Latency-Reversing Agent Combinations in Various In Vitro and Ex Vivo HIV-1 Latency Models Identified Bryostatin-1+JQ1 and Ingenol-B+JQ1 to Potently Reactivate Viral Gene Expression

PLOS Pathogens, 2015

The persistence of latently infected cells in patients under combinatory antiretroviral therapy (... more 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 latencyreversing agents (LRAs) and that their combinations led to synergistic activation of HIV-1 PLOS Pathogens | 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.

Research paper thumbnail of Raltegravir in HIV-1 Infected Pregnant Women: Pharmacokinetics, Safety and Efficacy

Clinical infectious diseases : an official publication of the Infectious Diseases Society of America, Jan 5, 2015

The use of raltegravir in HIV-infected pregnant women is important in the prevention of mother-t... more The use of raltegravir in HIV-infected pregnant women is important in the prevention of mother-to-child HIV transmission (MTCT), especially in circumstances when a rapid decline of HIV RNA viral 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. An open-label, multi-centre, phase IV study in HIV-infected pregnant women receiving raltegravir 400 mg twice daily, was performed (PANNA Network). Steady state pharmacokinetic profiles were obtained in the third trimester and postpartum along with cord and maternal delivery concentrations. Safety and virological efficacy were evaluated. 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...

Research paper thumbnail of Comparison of Methods for In-House Screening of HLA-B*57:01 to Prevent Abacavir Hypersensitivity in HIV-1 Care

PLOS ONE, 2015

Abacavir is a nucleoside reverse transcriptase inhibitor used as part of combination antiretrovir... more 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*57:01allotype, 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.

Research paper thumbnail of Atazanavir exposure is effective during pregnancy regardless of tenofovir use

Antiviral therapy, Jan 3, 2014

We studied the effect of pregnancy on atazanavir pharmacokinetics in the presence and absence of ... more We studied the effect of pregnancy on atazanavir pharmacokinetics in the presence and absence of tenofovir. This was a non-randomized, open-label, multicentre Phase IV study in HIV-infected pregnant women recruited from European HIV treatment centres. HIV-infected pregnant women treated with boosted atazanavir (300/100 mg or 400/100 mg atazanavir/ritonavir) as part of their combination antiretroviral therapy (cART) were included in the study. 24 h pharmacokinetic curves were recorded in the third trimester and postpartum. Collection of a cord blood and maternal sample at delivery was optional. 31 patients were included in the analysis, 21/31 patients used tenofovir as part of cART. Median (range) gestational age at delivery was 39 weeks (36-42). Approaching delivery 81% (25 patients) had an HIV viral load <50 copies/ml, all <1,000 copies/ml. Least squares means ratios (90% CI) of atazanavir pharmacokinetic parameters third trimester/postpartum were: 0.66 (0.57, 0.75) for AUC0-...

Research paper thumbnail of Pharmacokinetics of total and unbound darunavir in HIV-1-infected pregnant women

The Journal of antimicrobial chemotherapy, 2015

To describe the pharmacokinetics of darunavir in pregnant HIV-infected women in the third trimest... more To describe the pharmacokinetics of darunavir in pregnant HIV-infected women in the third trimester and post-partum. This was a non-randomized, open-label, multicentre, Phase IV study in HIV-infected pregnant women recruited from HIV treatment centres in Europe. HIV-infected pregnant women treated with darunavir (800/100 mg once daily or 600/100 mg twice daily) as part of their combination ART were included. Pharmacokinetic curves were recorded in the third trimester and post-partum. A cord blood sample and maternal sample were collected. The study is registered at ClinicalTrials.gov under number NCT00825929. Twenty-four women were included in the analysis [darunavir/ritonavir: 600/100 mg twice daily (n = 6); 800/100 mg once daily (n = 17); and 600/100 mg once daily (n = 1)]. Geometric mean ratios of third trimester versus post-partum (90% CI) were 0.78 (0.60-1.00) for total darunavir AUC0-tau after 600/100 mg twice-daily dosing and 0.67 (0.56-0.82) for total darunavir AUC0-tau afte...

Research paper thumbnail of First-line therapy with LPV/r vs NVP and 2 NRTIs in a developing country: W144 of a randomized trial

BMC Infectious Diseases, 2014

In resource-limited countries, NNRTI-based regimen may result in emergence of more HIV drug resis... more In resource-limited countries, NNRTI-based regimen may result in emergence of more HIV drug resistance because of a low genetic barrier. We compare the efficacy and tolerance of LPV/r and NVP-based regimens and 2 WHO nucleoside backbones in naive HIV infected patients (p.).

Research paper thumbnail of Synergistic Activation of HIV-1 Expression by Deacetylase Inhibitors and Prostratin: Implications for Treatment of Latent Infection

PLoS ONE, 2009

The persistence of transcriptionally silent but replication-competent HIV-1 reservoirs in Highly ... more 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)-kB 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 59 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-kB and degradation of cytoplasmic NF-kB inhibitor, IkBa . 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.

Research paper thumbnail of Risk factors of osteopenia in HIV-infected women: No role of antiretroviral therapy

Maturitas, 2010

Osteopenia and osteoporosis are more frequent in HIV-infected patients. Whether antiretroviral th... more Osteopenia and osteoporosis are more frequent in HIV-infected patients. Whether antiretroviral therapy induces a bone mineral density (BMD) loss remains controversial and few data are available in women. This cross-sectional study of 89 pre-menopausal HIV-infected women evaluates the relationship between BMD and antiretroviral treatment. Three groups of women were compared: women never treated (n=37), women treated with nucleoside reverse transcriptase inhibitors and non-nucleoside reverse transcriptase inhibitors and never treated with protease inhibitor (PI) (n=25) and women treated with a PI-containing regimen (n=27). Their lumbar spine and hip BMD was measured by dual-energy X-ray absorptiometry. We assessed also demographic parameters, body mass index (BMI), habits, history of HIV infection and treatment, lipodystrophy and metabolic and hormonal parameters. 83% were African women. Mean age was 37 years. Median duration of HIV treatment was 3.5 years. The overall prevalence of osteopenia/porosis was 31.5%. No difference was found between the three groups. Using logistic regression, low BMI was the only factor associated with osteopenia/porosis. Osteopenia/porosis was highly prevalent among these HIV-infected pre-menopausal women, mainly of African origin. BMD loss was not associated with antiretroviral therapy (containing PI or not) but was associated with a low BMI.

Research paper thumbnail of Darunavir in patients who failed on fos-amprenavir: efficacy at week 48

Journal of the International AIDS Society, 2008

Research paper thumbnail of Evolution of genotypic resistance to enfuvirtide in HIV-1 isolates from different group M subtypes

Journal of Clinical Virology, 2009

Background: Enfuvirtide is active against isolates from different HIV-1 subtypes. In vitro and in... more Background: Enfuvirtide is active against isolates from different HIV-1 subtypes. In vitro and in vivo studies reveal that resistance mutations are primarily found within the region spanning amino acid 36-45 of gp41. However, most studies include only subtype B strains, while it is known that especially the env region is very divergent among subtypes. Objectives: To analyze the gp41 HR1 genetic evolution during failure of enfuvirtide-containing salvage regimens in 19 HIV-1 patients infected with strains from different group M subtypes. Study design: The gp41 sequence was determined at baseline and upon failure in 19 patients. For a subset of 7 patients, samples were available after discontinuation of enfuvirtide. Results: Our results confirmed the conserved nature of the HR1 region. Escape mutants during chronic treatment with enfuvirtide were mainly observed within region 36-45. One novel mutation was identified, i.e. S42G in a subtype A1 strain. Conclusions: Different subtypes escape enfuvirtide selective pressure through similar mutational patterns, however a new S42G variant was observed. The in vivo selection of S42G suggests that it might play a role in enfuvirtide resistance. Therefore, it could be considered as a candidate mutation to be included within drug resistance interpretation systems.

Research paper thumbnail of Comparison of phenotypic and genotypic tropism determination in triple-class-experienced HIV patients eligible for maraviroc treatment

Journal of Antimicrobial Chemotherapy, 2011

Background: Determination of HIV-1 tropism is a pre-requisite to the use of CCR5 antagonists. Thi... more Background: Determination of HIV-1 tropism is a pre-requisite to the use of CCR5 antagonists. This study evaluated the potential of population genotypic tropism tests (GTTs) in clinical practice, and the correlation with phenotypic tropism tests (PTTs) in patients accessing routine HIV care.

Research paper thumbnail of The rare HIV-1 gp41 mutations 43T and 50V elevate enfuvirtide resistance levels of common enfuvirtide resistance mutations that did not impact susceptibility to sifuvirtide

Antiviral Research, 2010

Mutations that are selected at low frequency and/or reside outside the enfuvirtide target region,... more Mutations that are selected at low frequency and/or reside outside the enfuvirtide target region, amino acid 36-45 of gp41, might still be important determinants for drug resistance. This study aimed to investigate the phenotypic impact against enfuvirtide and sifuvirtide of uncharacterized gp41 mutations 42G, 43T and 50V, selected in patients failing enfuvirtide-containing regimens. As single mutations, neither 42G, 43T nor 50V conferred resistance to enfuvirtide. However, 50V increased slightly resistance levels for 36D, 38M, 43D or 43T as did 43T for 38M. All mutants displayed a reduced replication capacity, except 42S, 50V and 36D ± 50V. None of the mutants displayed resistance to the next-generation fusion inhibitor sifuvirtide. This study highlights the necessity to confirm the in vitro effect of infrequently selected mutations as 42G was not associated with enfuvirtide resistance whereas 43T and 50V should be considered as secondary enfuvirtide resistance mutations.

Research paper thumbnail of First-line antiretroviral therapy with nevirapine versus lopinavir-ritonavir based regimens in a resource-limited setting

AIDS, 2014

To compare WHO first-line antiretroviral therapy (ART) with nonnucleoside reverse transcriptase i... more To compare WHO first-line antiretroviral therapy (ART) with nonnucleoside reverse transcriptase inhibitors (NNRTI)-based regimen with a boosted protease inhibitor (bPI) regimen in a resource-limited setting regarding treatment outcome and emergence of drug resistance mutations (DRMs). Treatment-naive adults were randomized to nevirapine (NVP) or ritonavir-boosted lopinavir (LPV/r) regimens each in combination with tenofovir (TDF)/emtricitabine (FTC) or zidovudine (ZDV)/lamivudine (3TC). Primary endpoint was the incidence of therapeutical (clinical and/or virologic) failure at week 48 with follow-up till week 96. Four hundred and twenty-five patients (120 men; 305 women) received at least one dose of the study drug. mITT analysis showed no difference in proportion of therapeutical failure between treatment arms [67/209 (32%) in NVP vs. 63/216 (29%) LPV/r at week 48 (P = 0.53); 88/209 (42%) in NVP vs. 83/216 (38%) in LPV/r at week 96 (P = 0.49)]. Per-protocol analysis demonstrated significantly more virologic failure with NVP than with LPV/r regimens [at week 48: 19/167 (11%) vs. 7/166 (4%), P = 0.014; at week 96: 27/158 (17%) vs. 13/159 (8%), P = 0.019)]. Drug resistance mutations to NNRTI were detected in 19 out of 22 (86.3%) and dual-class resistance to nucleoside reverse transcriptase inhibitor (NRTI) and NNRTI in 15 out of 27 (68.2%) of NVP failing patients. K65R mutation was present in seven out of 14 patients failing NVP-TDF/FTC regimen. No major protease inhibitor-DRM was detected among LPV/r failing patients. Discontinuation for adverse events was similar between treatment groups. In resource-limited settings, first-line NNRTI-NRTI regimen as compared with bPI-based regimen provides similar outcome but is associated with a significantly higher number of virologic failure and resistance mutations in both classes that jeopardize future options for second-line therapy.

Research paper thumbnail of Tuning of AKT-pathway by Nef and its blockade by protease inhibitors results in limited recovery in latently HIV infected T-cell line

Scientific reports, Jan 14, 2016

Akt signaling plays a central role in many biological processes, which are key players in human i... more 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...

Research paper thumbnail of Sequential treatment with 5-aza-2'-deoxycytidine and deacetylase inhibitors reactivates HIV-1

EMBO molecular medicine, Jan 17, 2015

Reactivation of HIV gene expression in latently infected cells together with an efficient cART ha... more 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. Tak...

Research paper thumbnail of An In-Depth Comparison of Latency-Reversing Agent Combinations in Various In Vitro and Ex Vivo HIV-1 Latency Models Identified Bryostatin-1+JQ1 and Ingenol-B+JQ1 to Potently Reactivate Viral Gene Expression

PLOS Pathogens, 2015

The persistence of latently infected cells in patients under combinatory antiretroviral therapy (... more 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 latencyreversing agents (LRAs) and that their combinations led to synergistic activation of HIV-1 PLOS Pathogens | 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.

Research paper thumbnail of Risk Factors for HCV Acquisition Among HIV-Positive MSM in Belgium

JAIDS Journal of Acquired Immune Deficiency Syndromes, 2015

Objective: To better understand risk factors for the sexual transmission of hepatitis C (HCV) inf... more Objective: To better understand risk factors for the sexual transmission of hepatitis C (HCV) infection among MSM. Design: Case control study among HIV infected MSM, attending AIDS Reference Centers in Belgium. Methods: Cases were HIV infected MSM who were diagnosed with HCV between January 2010 and December 2013. For each case two controls were randomly selected from 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. Associations between HCV infection and risk factors were explored using bivariate analysis followed by multiple logistic regression analysis.

Research paper thumbnail of Synergistic Activation of HIV-1 Expression by Deacetylase Inhibitors and Prostratin: Implications for Treatment of Latent Infection

PLoS ONE, 2009

The persistence of transcriptionally silent but replication-competent HIV-1 reservoirs in Highly ... more 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)-kB 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 59 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-kB and degradation of cytoplasmic NF-kB inhibitor, IkBa . 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.

Research paper thumbnail of Tuning of AKT-pathway by Nef and its blockade by protease inhibitors results in limited recovery in latently HIV infected T-cell line

Akt signaling plays a central role in many biological processes, which are key players in human i... more 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.

Research paper thumbnail of Sequential treatment with 5-aza-2'-deoxycytidine and deacetylase inhibitors reactivates HIV-1

EMBO molecular medicine, Jan 17, 2015

Reactivation of HIV gene expression in latently infected cells together with an efficient cART ha... more 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. Tak...

Research paper thumbnail of An In-Depth Comparison of Latency-Reversing Agent Combinations in Various In Vitro and Ex Vivo HIV-1 Latency Models Identified Bryostatin-1+JQ1 and Ingenol-B+JQ1 to Potently Reactivate Viral Gene Expression

PLOS Pathogens, 2015

The persistence of latently infected cells in patients under combinatory antiretroviral therapy (... more 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 latencyreversing agents (LRAs) and that their combinations led to synergistic activation of HIV-1 PLOS Pathogens | 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.

Research paper thumbnail of Raltegravir in HIV-1 Infected Pregnant Women: Pharmacokinetics, Safety and Efficacy

Clinical infectious diseases : an official publication of the Infectious Diseases Society of America, Jan 5, 2015

The use of raltegravir in HIV-infected pregnant women is important in the prevention of mother-t... more The use of raltegravir in HIV-infected pregnant women is important in the prevention of mother-to-child HIV transmission (MTCT), especially in circumstances when a rapid decline of HIV RNA viral 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. An open-label, multi-centre, phase IV study in HIV-infected pregnant women receiving raltegravir 400 mg twice daily, was performed (PANNA Network). Steady state pharmacokinetic profiles were obtained in the third trimester and postpartum along with cord and maternal delivery concentrations. Safety and virological efficacy were evaluated. 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...

Research paper thumbnail of Comparison of Methods for In-House Screening of HLA-B*57:01 to Prevent Abacavir Hypersensitivity in HIV-1 Care

PLOS ONE, 2015

Abacavir is a nucleoside reverse transcriptase inhibitor used as part of combination antiretrovir... more 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*57:01allotype, 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.

Research paper thumbnail of Atazanavir exposure is effective during pregnancy regardless of tenofovir use

Antiviral therapy, Jan 3, 2014

We studied the effect of pregnancy on atazanavir pharmacokinetics in the presence and absence of ... more We studied the effect of pregnancy on atazanavir pharmacokinetics in the presence and absence of tenofovir. This was a non-randomized, open-label, multicentre Phase IV study in HIV-infected pregnant women recruited from European HIV treatment centres. HIV-infected pregnant women treated with boosted atazanavir (300/100 mg or 400/100 mg atazanavir/ritonavir) as part of their combination antiretroviral therapy (cART) were included in the study. 24 h pharmacokinetic curves were recorded in the third trimester and postpartum. Collection of a cord blood and maternal sample at delivery was optional. 31 patients were included in the analysis, 21/31 patients used tenofovir as part of cART. Median (range) gestational age at delivery was 39 weeks (36-42). Approaching delivery 81% (25 patients) had an HIV viral load <50 copies/ml, all <1,000 copies/ml. Least squares means ratios (90% CI) of atazanavir pharmacokinetic parameters third trimester/postpartum were: 0.66 (0.57, 0.75) for AUC0-...

Research paper thumbnail of Pharmacokinetics of total and unbound darunavir in HIV-1-infected pregnant women

The Journal of antimicrobial chemotherapy, 2015

To describe the pharmacokinetics of darunavir in pregnant HIV-infected women in the third trimest... more To describe the pharmacokinetics of darunavir in pregnant HIV-infected women in the third trimester and post-partum. This was a non-randomized, open-label, multicentre, Phase IV study in HIV-infected pregnant women recruited from HIV treatment centres in Europe. HIV-infected pregnant women treated with darunavir (800/100 mg once daily or 600/100 mg twice daily) as part of their combination ART were included. Pharmacokinetic curves were recorded in the third trimester and post-partum. A cord blood sample and maternal sample were collected. The study is registered at ClinicalTrials.gov under number NCT00825929. Twenty-four women were included in the analysis [darunavir/ritonavir: 600/100 mg twice daily (n = 6); 800/100 mg once daily (n = 17); and 600/100 mg once daily (n = 1)]. Geometric mean ratios of third trimester versus post-partum (90% CI) were 0.78 (0.60-1.00) for total darunavir AUC0-tau after 600/100 mg twice-daily dosing and 0.67 (0.56-0.82) for total darunavir AUC0-tau afte...

Research paper thumbnail of First-line therapy with LPV/r vs NVP and 2 NRTIs in a developing country: W144 of a randomized trial

BMC Infectious Diseases, 2014

In resource-limited countries, NNRTI-based regimen may result in emergence of more HIV drug resis... more In resource-limited countries, NNRTI-based regimen may result in emergence of more HIV drug resistance because of a low genetic barrier. We compare the efficacy and tolerance of LPV/r and NVP-based regimens and 2 WHO nucleoside backbones in naive HIV infected patients (p.).

Research paper thumbnail of Synergistic Activation of HIV-1 Expression by Deacetylase Inhibitors and Prostratin: Implications for Treatment of Latent Infection

PLoS ONE, 2009

The persistence of transcriptionally silent but replication-competent HIV-1 reservoirs in Highly ... more 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)-kB 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 59 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-kB and degradation of cytoplasmic NF-kB inhibitor, IkBa . 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.

Research paper thumbnail of Risk factors of osteopenia in HIV-infected women: No role of antiretroviral therapy

Maturitas, 2010

Osteopenia and osteoporosis are more frequent in HIV-infected patients. Whether antiretroviral th... more Osteopenia and osteoporosis are more frequent in HIV-infected patients. Whether antiretroviral therapy induces a bone mineral density (BMD) loss remains controversial and few data are available in women. This cross-sectional study of 89 pre-menopausal HIV-infected women evaluates the relationship between BMD and antiretroviral treatment. Three groups of women were compared: women never treated (n=37), women treated with nucleoside reverse transcriptase inhibitors and non-nucleoside reverse transcriptase inhibitors and never treated with protease inhibitor (PI) (n=25) and women treated with a PI-containing regimen (n=27). Their lumbar spine and hip BMD was measured by dual-energy X-ray absorptiometry. We assessed also demographic parameters, body mass index (BMI), habits, history of HIV infection and treatment, lipodystrophy and metabolic and hormonal parameters. 83% were African women. Mean age was 37 years. Median duration of HIV treatment was 3.5 years. The overall prevalence of osteopenia/porosis was 31.5%. No difference was found between the three groups. Using logistic regression, low BMI was the only factor associated with osteopenia/porosis. Osteopenia/porosis was highly prevalent among these HIV-infected pre-menopausal women, mainly of African origin. BMD loss was not associated with antiretroviral therapy (containing PI or not) but was associated with a low BMI.

Research paper thumbnail of Darunavir in patients who failed on fos-amprenavir: efficacy at week 48

Journal of the International AIDS Society, 2008

Research paper thumbnail of Evolution of genotypic resistance to enfuvirtide in HIV-1 isolates from different group M subtypes

Journal of Clinical Virology, 2009

Background: Enfuvirtide is active against isolates from different HIV-1 subtypes. In vitro and in... more Background: Enfuvirtide is active against isolates from different HIV-1 subtypes. In vitro and in vivo studies reveal that resistance mutations are primarily found within the region spanning amino acid 36-45 of gp41. However, most studies include only subtype B strains, while it is known that especially the env region is very divergent among subtypes. Objectives: To analyze the gp41 HR1 genetic evolution during failure of enfuvirtide-containing salvage regimens in 19 HIV-1 patients infected with strains from different group M subtypes. Study design: The gp41 sequence was determined at baseline and upon failure in 19 patients. For a subset of 7 patients, samples were available after discontinuation of enfuvirtide. Results: Our results confirmed the conserved nature of the HR1 region. Escape mutants during chronic treatment with enfuvirtide were mainly observed within region 36-45. One novel mutation was identified, i.e. S42G in a subtype A1 strain. Conclusions: Different subtypes escape enfuvirtide selective pressure through similar mutational patterns, however a new S42G variant was observed. The in vivo selection of S42G suggests that it might play a role in enfuvirtide resistance. Therefore, it could be considered as a candidate mutation to be included within drug resistance interpretation systems.

Research paper thumbnail of Comparison of phenotypic and genotypic tropism determination in triple-class-experienced HIV patients eligible for maraviroc treatment

Journal of Antimicrobial Chemotherapy, 2011

Background: Determination of HIV-1 tropism is a pre-requisite to the use of CCR5 antagonists. Thi... more Background: Determination of HIV-1 tropism is a pre-requisite to the use of CCR5 antagonists. This study evaluated the potential of population genotypic tropism tests (GTTs) in clinical practice, and the correlation with phenotypic tropism tests (PTTs) in patients accessing routine HIV care.

Research paper thumbnail of The rare HIV-1 gp41 mutations 43T and 50V elevate enfuvirtide resistance levels of common enfuvirtide resistance mutations that did not impact susceptibility to sifuvirtide

Antiviral Research, 2010

Mutations that are selected at low frequency and/or reside outside the enfuvirtide target region,... more Mutations that are selected at low frequency and/or reside outside the enfuvirtide target region, amino acid 36-45 of gp41, might still be important determinants for drug resistance. This study aimed to investigate the phenotypic impact against enfuvirtide and sifuvirtide of uncharacterized gp41 mutations 42G, 43T and 50V, selected in patients failing enfuvirtide-containing regimens. As single mutations, neither 42G, 43T nor 50V conferred resistance to enfuvirtide. However, 50V increased slightly resistance levels for 36D, 38M, 43D or 43T as did 43T for 38M. All mutants displayed a reduced replication capacity, except 42S, 50V and 36D ± 50V. None of the mutants displayed resistance to the next-generation fusion inhibitor sifuvirtide. This study highlights the necessity to confirm the in vitro effect of infrequently selected mutations as 42G was not associated with enfuvirtide resistance whereas 43T and 50V should be considered as secondary enfuvirtide resistance mutations.

Research paper thumbnail of First-line antiretroviral therapy with nevirapine versus lopinavir-ritonavir based regimens in a resource-limited setting

AIDS, 2014

To compare WHO first-line antiretroviral therapy (ART) with nonnucleoside reverse transcriptase i... more To compare WHO first-line antiretroviral therapy (ART) with nonnucleoside reverse transcriptase inhibitors (NNRTI)-based regimen with a boosted protease inhibitor (bPI) regimen in a resource-limited setting regarding treatment outcome and emergence of drug resistance mutations (DRMs). Treatment-naive adults were randomized to nevirapine (NVP) or ritonavir-boosted lopinavir (LPV/r) regimens each in combination with tenofovir (TDF)/emtricitabine (FTC) or zidovudine (ZDV)/lamivudine (3TC). Primary endpoint was the incidence of therapeutical (clinical and/or virologic) failure at week 48 with follow-up till week 96. Four hundred and twenty-five patients (120 men; 305 women) received at least one dose of the study drug. mITT analysis showed no difference in proportion of therapeutical failure between treatment arms [67/209 (32%) in NVP vs. 63/216 (29%) LPV/r at week 48 (P = 0.53); 88/209 (42%) in NVP vs. 83/216 (38%) in LPV/r at week 96 (P = 0.49)]. Per-protocol analysis demonstrated significantly more virologic failure with NVP than with LPV/r regimens [at week 48: 19/167 (11%) vs. 7/166 (4%), P = 0.014; at week 96: 27/158 (17%) vs. 13/159 (8%), P = 0.019)]. Drug resistance mutations to NNRTI were detected in 19 out of 22 (86.3%) and dual-class resistance to nucleoside reverse transcriptase inhibitor (NRTI) and NNRTI in 15 out of 27 (68.2%) of NVP failing patients. K65R mutation was present in seven out of 14 patients failing NVP-TDF/FTC regimen. No major protease inhibitor-DRM was detected among LPV/r failing patients. Discontinuation for adverse events was similar between treatment groups. In resource-limited settings, first-line NNRTI-NRTI regimen as compared with bPI-based regimen provides similar outcome but is associated with a significantly higher number of virologic failure and resistance mutations in both classes that jeopardize future options for second-line therapy.