Audrey Rodallec

RhoA GTPase regulates radiation-induced alterations in endothelial cell adhesion and migration.

Endothelial cells of the microvasculature are major target of ionizing radiation, responsible of the radiation-induced vascular early dysfunctions. Molecular signaling pathways involved in endothelial responses to ionizing radiation, despite being increasingly investigated, still need precise characterization. Small GTPase RhoA and its effector ROCK are crucial signaling molecules involved in many endothelial cellular functions. Recent studies identified implication of RhoA/ROCK in radiation-induced increase in endothelial permeability but other endothelial functions altered by radiation might also require RhoA proteins. Human microvascular endothelial cells HMEC-1, either treated with Y-27632 (inhibitor of ROCK) or invalidated for RhoA by RNA interference were exposed to 15Gy. We showed a rapid radiation-induced activation of RhoA, leading to a deep reorganisation of actin cytoskeleton with rapid formation of stress fibers. Endothelial early apoptosis induced by ionizing radiation was not affected by Y-27632 pre-treatment or RhoA depletion. Endothelial adhesion to fibronectin and formation of focal adhesions increased in response to radiation in a RhoA/ROCK-dependent manner. Consistent with its pro-adhesive role, ionizing radiation also decreased endothelial cells migration and RhoA was required for this inhibition. These results highlight the role of RhoA GTPase in ionizing radiation-induced deregulation of essential endothelial functions linked to actin cytoskeleton.

Levels of intracellular HIV-DNA in patients with suppressive antiretroviral therapy.

Objective:The objective of this study is to study factors associated with HIV-DNA levels in chronically infected patients on long-term suppressive antiretroviral therapy (ART). Design:A cross-sectional, multicentre study of patients receiving ART for more than 3 years, HIV-RNA less than 50 copies/ml for more than 2 years and CD4+ cell count more than 350 cells/&mgr;l. Method:Factors associated with low (<150) or high (>1000), compared with intermediate (150–1000 copies/106 PBMCs) levels of HIV-DNA were investigated using multinomial logistic regression. Results:Five hundred and twenty-two patients who initiated ART during the chronic phase were included (71% male; median peak HIV-RNA: 4.88 log10 copies/ml, CD4+ cell count nadir: 222 cells/&mgr;l). Median ART duration was 13 years [interquartile range (IQR) 7–17], viral suppression was 5.7 years (IQR 3.9–8.5) and 66% of the patients never experienced ART failure. Median HIV-DNA was 323 copies/106 PBMCs (IQR, 129–717) with low, intermediate and high levels observed in 28.3, 55.4 and 16.3%, respectively. In multivariable analysis, women were more likely to achieve a low level of HIV-DNA. Each additional year with suppressed HIV-RNA increased the likelihood of low level and decreased the likelihood of high level of HIV-DNA. Peak HIV-RNA higher than 5log10 was always associated with a decreased risk of low and an increased risk of high HIV-DNA. For patients with peak HIV-RNA lower than 5log10, past ART failure was associated with high level of HIV-DNA. Conclusion:Chronically HIV-infected patients with long-term suppressive ART can achieve low total HIV-DNA but one over six still presented HIV-DNA above 1000 copies/106 PBMCs despite long-term viral suppression.

Virological response to darunavir in patients infected with HIV is linked to darunavir resistance-associated mutations corrected by the count of mutations with positive impact and is not associated with pharmacological and combined virological/pharmacological parameters.

The relationships between virological (darunavir resistance–associated mutations), pharmacological (darunavir trough plasma concentration), combined virological/pharmacological [darunavir genotypic inhibitory quotient (GIQ)] parameters and virological response were evaluated in experienced patients infected with human immunodeficiency virus. In this retrospective study (48 patients), the relationship between these parameters and the virological response was investigated by multivariate logistic regression. Darunavir GIQ is defined as the ratio between darunavir trough plasma concentration and the count of darunavir resistance–associated mutations (V11I, V32I, L33F, I47V, I50V, I54L/M, T74P, L76V, I84V, L89V) corrected or not corrected by the count of mutations with positive impact (V82A and E35D). The pharmacological and combined virological/pharmacological parameters failed to predict virological response. The count of darunavir resistance–associated mutations corrected by the count of V82A and E35D mutations was the single parameter significantly (P = 0.027) associated with virological response. This result suggests that both negative and positive impacts of mutations including V82A and E35D should be considered to predict virological response in experienced patients.

Phenotypic analysis of HIV-1 E157Q integrase polymorphism and impact on virological outcome in patients initiating an integrase inhibitor-based regimen

Objectives To assess the phenotypic susceptibility of the E157Q polymorphism in HIV-1 integrase (IN) and the virological outcome of patients infected with E157Q-mutated virus initiating an IN inhibitor (INI)-based regimen. Methods This was a multicentre study assessing IN sequences from INI-naive patients among 17 French HIV clinical centres. E157Q site-directed mutants in pNL4.3 and pCRF02_AG contexts were assessed in a recombinant phenotypic assay. Results Prevalence of the E157Q polymorphism was 2.7% among 8528 IN sequences from INI-naive patients and its distribution was 1.7%, 5.6% and 2.2% in B, CRF02_AG and various non-B subtypes, respectively. Thirty-nine INI-naive patients with E157Q-mutated virus initiated an INI-based regimen. Among them, 15 had a viral load (VL) <50 copies/mL at initiation and virological suppression was maintained during the first year of follow-up in all but two exhibiting a viral blip. Twenty-four patients had a VL > 50 copies/mL at the time of INI-based regimen initiation. Among them eight were receiving a first-line regimen and the only two patients who did not reach VL < 50 copies/mL at week 24 were receiving elvitegravir. The 16 remaining patients were ART experienced in virological failure with drug-resistant viruses displaying several virological outcomes independently of the genotypic susceptibility score. Phenotypic analyses showed a fold change in EC50 of 0.6, 0.9 and 1.9 for raltegravir, dolutegravir and elvitegravir, respectively, in a subtype B context, and 1.1, 1.9 and 2.4 for raltegravir, dolutegravir and elvitegravir, respectively, in a CRF02_AG context. Conclusions Assessment of virological response in 39 patients initiating an INI-based regimen with E157Q-mutated virus, in combination with phenotypic analysis, suggests that particular attention should be paid to antiretroviral-naive patients and dolutegravir should be preferentially used in these patients.

Interlaboratory quality control of total HIV-1 DNA load measurement for multicenter reservoir studies†

Viral reservoirs represent an important barrier to HIV cure. Accurate markers of HIV reservoirs are needed to develop multicenter studies. The aim of this multicenter quality control (QC) was to evaluate the inter‐laboratory reproducibility of total HIV‐1‐DNA quantification.

Optimizing the virological success of tenofovir DF/FTC/rilpivirine in HIV-infected naive and virologically suppressed patients through strict clinical and virological selection*

Abstract Background: Tenofovir DF/FTC/rilpivirine (TDF/FTC/RPV) is a single tablet regimen considered as safe and efficacious in HIV population as long as food requirements, concomitant PPI administration, and compromised antiviral activity have been carefully reviewed. We evaluated TDF/FTC/RPV in a real-life setting with focus on clinical and virological outcomes. Methods: OCEAN II is a prospective, two-centre observational study. From September 2012 to December 2013, antiretroviral-naive patients with HIV RNA <100,000 copies/mL or wishing to switch for simplification were considered for TDF/FTC/RPV. A systematic review of potential obstacles to TDF/FTC/RPV administration was undertaken during a multidisciplinary meeting, including DNA genotyping to detect archived RPV and/or NRTI-associated resistance mutations if historical RNA resistance testing was lacking. Results: TDF/FTC/RPV was considered for 480 patients, however was not offered to 194 patients (40%), mainly because of risk of insufficient virological efficacy, issues on adherence, patient refusal, meal constraint, or PPI therapy. A total of 286 patients (269 in maintenance; 17 ART-naive) received TDF/FTC/RPV. After a median follow-up of 30 months, virological failure occurred in five patients (1.7%) without the emergence of resistance mutations. Discontinuation of TDF/FTC/RPV occurred in 98 patients, due to adverse events in 43 patients (44%) and non-safety reasons in 55 patients (56%). No grade three-fourth adverse events occurred. Conclusion: In this real-life experience, cohort consisting primarily of virologically suppressed patients, TDF/FTC/RPV usually maintained virologic suppression. Discontinuation of therapy because of intolerability was due to mild adverse events. Strict clinical and virological screening probably explained the low rate of virological failure.

Evaluation of residual viremia and quantitation of soluble CD14 in a large cohort of HIV-infected adults on a long-term non-nucleoside reverse transcriptase inhibitor-based regimen.

Beyond virological suppression and immunologic recovery, the objective of long‐term antiretroviral therapy is to suppress maximally viremia and to control for persistent immune activation. Non‐nucleoside reverse transcriptase inhibitor (NNRTI)‐containing regimens are associated with lower residual viremia. The objective of the study was to evaluate the impact of long term NNRTI‐containing treatment on residual viremia and on monocyte activation in a cohort of patients infected with HIV‐1. To identify factors associated with residual viremia, adult patients infected with HIV on nevirapine or efavirenz‐based therapy with viral load <50 copies/ml for >6 months were included. Residual plasma viremia was quantified using an adapted Cobas/Taqman HIV‐1 assay. Viral loads with no detected signal were considered as <1 copy/ml. Monocyte activation was evaluated by quantitation of plasma sCD14 by ELISA assay at the time of residual viremia measurement. Logistic regression was used to determine factors associated with residual viremia <1 copy/ml. In this cohort of 421 patients on long‐term NNRTI regimen, three quarters had a residual viremia <1 copy/ml. In multivariate analysis, duration of plasma viral load below 50 copies/ml was the only factor associated with residual viremia <1 copy/ml. Soluble CD14 was in the normal range although treatment with nevirapine was associated with a significant lower level of sCD14 compared to efavirenz. Residual viremia <1 copy/ml was frequent in this cohort of patients with long term virological control and confirmed the results of previous studies. Apart from its antiviral effect, nevirapine as well as efavirenz could decrease monocyte activation. J Med. Virol. 85:1878–1882, 2013.

The Immune Response to the RT181-189 Epitope in HIV-1-Infected Patients is Associated with Viral Sequence Polymorphism Flanking the Epitope

Many drug-resistance mutations in HIV-1 reverse transcriptase fall within cytotoxic T lymphocytes (CTL) epitopes, but studies of the response to these epitopes in patients with virological failure are lacking. We therefore compared IFN-γ ELISPOT responses to the YV9 epitope (RT181-189) covering the lamivudine resistance mutation, M184V, in HLA-A2+ antiretroviral treatment (ART)-naive patients (n = 19), to those found in HLA-A2+ patients with virological failure (n = 15). Ten ART-naive patients had an ELISPOT response to the wild-type epitope that cross-reacted with the mutant epitope. Two patients with virological failure showed a specific response to the 184V mutant epitope. Responses against YV9 were strongly associated (p = 0.005) with the presence of a 177E mutation, and the same tendency was observed in an independent cohort of patients (n = 22). These results indicate that variants in flanking residues may influence CTL responses to conserved subdominant HIV-1 epitopes.

HCMV triggers frequent and persistent UL40-specific unconventional HLA-E-restricted CD8 T-cell responses with potential autologous and allogeneic peptide recognition

Immune response against human cytomegalovirus (HCMV) includes a set of persistent cytotoxic NK and CD8 T cells devoted to eliminate infected cells and to prevent reactivation. CD8 T cells against HCMV antigens (pp65, IE1) presented by HLA class-I molecules are well characterized and they associate with efficient virus control. HLA-E-restricted CD8 T cells targeting HCMV UL40 signal peptides (HLA-EUL40) have recently emerged as a non-conventional T-cell response also observed in some hosts. The occurrence, specificity and features of HLA-EUL40 CD8 T-cell responses remain mostly unknown. Here, we detected and quantified these responses in blood samples from healthy blood donors (n = 25) and kidney transplant recipients (n = 121) and we investigated the biological determinants involved in their occurrence. Longitudinal and phenotype ex vivo analyses were performed in comparison to HLA-A*02/pp65-specific CD8 T cells. Using a set of 11 HLA-E/UL40 peptide tetramers we demonstrated the presence of HLA-EUL40 CD8 αβT cells in up to 32% of seropositive HCMV+ hosts that may represent up to 38% of total circulating CD8 T-cells at a time point suggesting a strong expansion post-infection. Host’s HLA-A*02 allele, HLA-E *01:01/*01:03 genotype and sequence of the UL40 peptide from the infecting strain are major factors affecting the incidence of HLA-EUL40 CD8 T cells. These cells are effector memory CD8 (CD45RAhighROlow, CCR7-, CD27-, CD28-) characterized by a low level of PD-1 expression. HLA-EUL40 responses appear early post-infection and display a broad, unbiased, Vβ repertoire. Although induced in HCMV strain-dependent, UL4015-23-specific manner, HLA-EUL40 CD8 T cells are reactive toward a broader set of nonapeptides varying in 1–3 residues including most HLA-I signal peptides. Thus, HCMV induces strong and life-long lasting HLA-EUL40 CD8 T cells with potential allogeneic or/and autologous reactivity that take place selectively in at least a third of infections according to virus strain and host HLA concordance.

Severe symptomatic primary HCMV infection despite effective innate and adaptive immune responses

ABSTRACT Primary human cytomegalovirus (HCMV) infection usually goes unnoticed, causing mild or no symptoms in immunocompetent individuals. However, some rare severe clinical cases have been reported without investigation of host immune responses or viral virulence. In the present study, we investigate for the first time phenotypic and functional features, together with gene expression profiles in immunocompetent adults experiencing a severe primary HCMV infection. Twenty primary HCMV-infected patients (PHIP) were enrolled, as well as 26 HCMV-seronegative and 39 HCMV-seropositive healthy controls. PHIP had extensive lymphocytosis marked by massive expansion of natural killer (NK) and T cell compartments. Interestingly, PHIP mounted efficient innate and adaptive immune responses with a deep HCMV imprint, revealed mainly by the expansion of NKG2C+ NK cells, CD16+ Vδ2(−) γδ T cells, and conventional HCMV-specific CD8+ T cells. The main effector lymphocytes were activated and displayed an early immune phenotype that developed toward a more mature differentiated status. We suggest that both massive lymphocytosis and excessive lymphocyte activation could contribute to massive cytokine production, known to mediate tissue damage observed in PHIP. Taken together, these findings bring new insights into the comprehensive understanding of immune mechanisms involved during primary HCMV infection in immunocompetent individuals. IMPORTANCE HCMV-specific immune responses have been extensively documented in immunocompromised patients and during in utero acquisition. While it usually goes unnoticed, some rare severe clinical cases of primary HCMV infection have been reported in immunocompetent patients. However, host immune responses or HCMV virulence in these patients has not so far been investigated. In the present study, we show massive expansion of NK and T cell compartments during the symptomatic stage of acute HCMV infection. The patients mounted efficient innate and adaptive immune responses with a deep HCMV imprint. The massive lymphocytosis could be the result of nonadapted or uncontrolled immune responses limiting the effectiveness of the specific responses mounted. Both massive lymphocytosis and excessive lymphocyte activation could contribute to massive cytokine production, known to mediate tissue damage. Furthermore, we cannot exclude a delayed immune response caused by immune escape established by HCMV strains.