Anne Simon

HIV disease progression despite suppression of viral replication is associated with exhaustion of lymphopoiesis

The mechanisms of CD4(+) T-cell count decline, the hallmark of HIV disease progression, and its relationship to elevated levels of immune activation are not fully understood. Massive depletion of CD4(+) T cells occurs during the course of HIV-1 infection, so that maintenance of adequate CD4(+) T-cell levels probably depends primarily on the capacity to renew depleted lymphocytes, that is, the lymphopoiesis. We performed here a comprehensive study of quantitative and qualitative attributes of CD34(+) hematopoietic progenitor cells directly from the blood of a large set of HIV-infected persons compared with uninfected donors, in particular the elderly. Our analyses underline a marked impairment of primary immune resources with the failure to maintain adequate lymphocyte counts. Systemic immune activation emerges as a major correlate of altered lymphopoiesis, which can be partially reversed with prolonged antiretroviral therapy. Importantly, HIV disease progression despite elite control of HIV replication or virologic success on antiretroviral treatment is associated with persistent damage to the lymphopoietic system or exhaustion of lymphopoiesis. These findings highlight the importance of primary hematopoietic resources in HIV pathogenesis and the response to antiretroviral treatments.

Genotypic Inhibitory Quotient as Predictor of Virological Response to Ritonavir-Amprenavir in Human Immunodeficiency Virus Type 1 Protease Inhibitor-Experienced Patients

ABSTRACT Forty-nine protease inhibitor (PI)-experienced but amprenavir (APV)-naïve patients experiencing virological failure were treated with ritonavir (RTV) (100 mg twice a day [b.i.d.]) plus APV (600 mg b.i.d.). Patients responded to therapy with a median viral load decrease of −1.32 log10 by week 12. The addition of low-dose RTV enhanced the minimal APV concentration in plasma (APV Cmin) up to 10-fold compared with that obtained with APV (1,200 mg b.i.d.) without RTV. Baseline PI resistance mutations (L10F/I/V, K20M/R, E35D, R41K, I54V, L63P, V82A/F/T/S, I84V) identified by univariate analysis and included in a genotypic score and APV Cmin at week 8 were predictive of the virological response at week 12. The response to APV plus RTV was significantly reduced in patients with six or more of the resistance mutations among the ones defined above. The genotypic inhibitory quotient, calculated as the ratio of the APV Cmin to the number of human immunodeficiency virus type 1 protease mutations, was a better predictor than the virological or pharmacological variables used alone. This genotypic inhibitory quotient could be used in therapeutic drug monitoring to define the concentrations in plasma needed to control replication of viruses with different levels of PI resistance, as measured by the number of PI resistance mutations.

Old age and anti-cytomegalovirus immunity are associated with altered T-cell reconstitution in HIV-1-infected patients.

Objective and design:Increasing evidence supports a parallel between HIV-1 infection and immune aging, which is particularly apparent with common changes in naive versus memory T-cell proportions. Here, we aimed at refining the value of common T-cell-associated markers of immunosenescence during HIV disease progression or aging, and at exploring further the impact in this context of old age as well as cytomegalovirus (CMV) co-infection, which is predominant in HIV-1-infected individuals. Methods:Frequencies of naive or CD57+ memory T cells as well as the magnitude of CMV-pp65 T cells were measured in HIV-1-infected patients grouped according to disease progression status, treatment and age. Results:Our results indicate that the decline in naive T-cell levels rather than the accumulation of CD57+ senescent T cells identifies best the premature development of an immunosenescence phenotype with HIV disease progression. Moreover, advanced age or mounting of strong CMV-specific responses impact independently on CD4+ T-cell counts and recovery with antiretroviral therapy. Conclusions:The present findings indicate that HIV-1 infection amplifies the effect of age on naive T-cell levels, and highlight the constraint on the capacity of treated patients to reconstitute their CD4+ T-cell compartment due to age and CMV co-infection.

Mechanisms Involved in the Low-Level Regeneration of CD4+ Cells in HIV-1—Infected Patients Receiving Highly Active Antiretroviral Therapy Who Have Prolonged Undetectable Plasma Viral Loads

BACKGROUND Persistent low CD4(+) cell counts are observed in 5%-27% of patients treated for human immunodeficiency virus (HIV)-1 infection despite their having prolonged undetectable plasma viral loads. METHODS To understand the possible mechanisms of this discordant immunological situation, a prospective transsectional case-control study was designed. HIV-1-infected subjects who had a plasma viral load <200 copies/mL for >1 year were considered to be case patients if their CD4(+) cell count was <250/mm(3); control patients had CD4(+) cell counts >500/mm(3) and were matched by sex, age, and nadir CD4(+) cell count to case patients. T cell proliferation after stimulation with various antigens, T cell subset counts, T cell rearrangement excision circles (TRECs), T cells undergoing apoptosis, cytokines influencing apoptosis, and cellular proviral DNA and plasma viral RNA persistence were assessed. RESULTS Compared with the 19 control patients, the 19 case patients had undistinguishable lymphoproliferative responses to candidin and cytomegalovirus, fewer naive CD4(+) cells (CD45RA(+)62L(+), 23%+/-13% vs. 47%+/-14%; P<.0001), lower thymic output (1.28 vs. 3.95 TRECs/microL of blood; P=.0015), increased cell death by apoptosis (spontaneous, 23.2%+/-8.3% vs. 11.9%+/-8.4% [P=.02]; Fas induced, 38.6%+/-13.7% vs. 16.4%+/-8.0% [P=.004]), higher levels of plasma soluble tumor necrosis factor receptor II (9.6 vs. 5.3 ng/mL; P=.0058), and undistinguishable plasma HIV-1 and cellular proviral DNA loads. CONCLUSIONS The mechanisms responsible for the low-level regeneration of CD4(+) cells involve, at least, deficiency in the regeneration of central CD4(+) cells and excessive apoptosis.

Oncologic Trogocytosis of an Original Stromal Cells Induces Chemoresistance of Ovarian Tumours

Background The microenvironment plays a major role in the onset and progression of metastasis. Epithelial ovarian cancer (EOC) tends to metastasize to the peritoneal cavity where interactions within the microenvironment might lead to chemoresistance. Mesothelial cells are important actors of the peritoneal homeostasis; we determined their role in the acquisition of chemoresistance of ovarian tumours. Methodology/Principal Findings We isolated an original type of stromal cells, referred to as “Hospicells” from ascitis of patients with ovarian carcinosis using limiting dilution. We studied their ability to confer chemoresistance through heterocellular interactions. These stromal cells displayed a new phenotype with positive immunostaining for CD9, CD10, CD29, CD146, CD166 and Multi drug resistance protein. They preferentially interacted with epithelial ovarian cancer cells. This interaction induced chemoresistance to platin and taxans with the implication of multi-drug resistance proteins. This contact enabled EOC cells to capture patches of the Hospicells membrane through oncologic trogocytosis, therefore acquiring their functional P-gp proteins and thus developing chemoresistance. Presence of Hospicells on ovarian cancer tissue micro-array from patients with neo-adjuvant chemotherapy was also significantly associated to chemoresistance. Conclusions/Significance This is the first report of trogocytosis occurring between a cancer cell and an original type of stromal cell. This interaction induced autonomous acquisition of chemoresistance. The presence of stromal cells within patients tumour might be predictive of chemoresistance. The specific interaction between cancer cells and stromal cells might be targeted during chemotherapy.

Re-occurrence of HIV-1 drug mutations after treatment re-initiation following interruption in patients with multiple treatment failure.

Antiretroviral treatment interruption in 20 extensively pre-treated HIV-1 patients with treatment failure led to genotype viral reversion of at least one class of drug-mutation resistance in half of the patients. The only predictive factor of reversion was found to be the duration of interruption. The outgrowth of residual wild-type virus seems not to be a true genetic reversion because drug mutations are detected rapidly at salvage therapy re-initiation.

Partially active HIV-1 Vif alleles facilitate viral escape from specific antiretrovirals.

Background:The HIV-1 Vif protein counteracts the antiviral activity of the cytidine deaminases APOBEC3G and APOBEC3F. Natural variation in Vif may result in reduced efficacy against APOBEC3 proteins and in increased HIV-1 diversity. We speculated that this mechanism could facilitate viral escape from certain antiretroviral drugs. Methods and results:We analyzed the protease, reverse transcriptase and Vif sequences of viruses from plasma obtained from 92 HIV-1-infected individuals failing antiretroviral treatment and 65 antiretroviral-naive patients. Mutation K22H in Vif was more frequent in patients failing to antiretroviral compared to antiretroviral-naive patients. In-vitro experiments showed that mutant K22H failed to completely neutralize APOBEC3G. Upon infection of MT-2 cells, most of the K22H proviral clones encoded increased numbers of G-to-A mutations. Among these mutations, the lamivudine drug-resistance-associated mutation M184I in reverse transcriptase was detected in 25% of clones in the absence of any lamivudine exposure. In our population, among pretreated patients, 72% of K22H viruses versus 42% in WT K22 viruses harbored at least two drug-resistance-associated mutations in a GA/GG dinucleotide context. More specifically, K22H viruses harbored significantly more G16E and M36I in protease than in those isolated from pretreated patients harboring WT K22 viruses. Conclusions:This study provides evidence that patients experiencing virological failure frequently harbor Vif point mutants (i.e. K22H). Such Vif alleles lose their ability to counteract APOBEC3 proteins, leading to an increase of G-to-A viral mutations that can facilitate the emergence of some antiretroviral resistance mutations.

Human CD90 Identifies Th17/Tc17 T Cell Subsets That Are Depleted in HIV-Infected Patients

By revisiting CD90, a GPI-anchored glycoprotein, we show that CD90 is expressed by a subset of CD4+ and CD8+ human T cells. CD4+CD90+ cells share similarities with Th17 cells because they express the Th17-specific transcription factor RORC2 and produce IL-17A. CD4+CD90+ cells are activated memory T cells that express the gut mucosal markers CCR6, CD161, and the α4 and β7 integrins. Compared with CD90-depleted CCR6+ memory Th17 cells, CD4+CD90+ cells express higher levels of IL-22 and proinflammatory cytokines (IL-6, TNF-α and GM-CSF), but they produce lower levels of IL-21 and no IL-9. Analyses of CD8+CD90+ cells reveal that they express RORC2 and are able to produce higher levels of IL-17A, IL-22, and CCL20 compared with CD90-depleted CD8+ cells. These data show that CD90 identifies Th17 and Tc17 cells with a peculiar cytokine profile. Studies of circulating CD90+ cells in HIV patients show that CD90+ cells are decreased with an imbalance of the CD4+CD90+/regulatory T cell ratio in nontreated patients compared with treated patients and healthy donors. Overall, human CD90 identifies a subset of Th17 and Tc17 cells within CD4+ and CD8+ T cells, respectively, which are depleted during HIV infection.

Cohort Profile: French hospital database on HIV (FHDH-ANRS CO4)

The French Hospital Database on HIV (FHDH) is a hospital-based multicentre open cohort with inclusions ongoing since 1989. The research objectives focus mainly on mid- and long-term clinical outcomes and therapeutic strategies, as well as severe AIDS and non-AIDS morbidities, and public health issues relative to HIV infection. FHDH also serves to describe HIV-infected patients receiving hospital care in France. FHDH includes data on more than 120,000 HIV-infected patients from 70 French general or university hospitals distributed throughout France. Patients are eligible for inclusion if they are infected by HIV-1 or HIV-2 and give their written informed consent. Standardized variables are collected at each outpatient visit or hospital admission during which a new clinical manifestation is diagnosed, a new treatment is prescribed or a change in biological markers is noted, and/or at least every 6 months. Since its inception, variables collected in FHDH include demographic characteristics, HIV-related biological markers, the date and type of AIDS and non AIDS-defining events, antiretroviral treatments and the date and causes of death, as reported in the medical records. Since 2005, data have also been collected on: co-infection with hepatitis B or C virus; alcohol and tobacco use; and non HIV-related biomarkers. Anyone can submit a research project by completing a standardized form available on the FHDH website (http://www.ccde.fr/_fold/fl-1385734776-429.pdf) or from the corresponding author, describing the context and objectives of the study. All projects are reviewed by the scientific committee.

E138K and M184I mutations in HIV-1 reverse transcriptase coemerge as a result of APOBEC3 editing in the absence of drug exposure.

Background:Recent clinical trials with rilpivirine combined with emtricitabine and tenofovir revealed that patients failing treatment, frequently, harbored viruses encoding resistance-associated mutations in the HIV-1 reverse transcriptase at position E138K and M184I. We show here that APOBEC3 proteins play a role in the emergence of these drug resistance mutations. Methods:We used a Vif mutant that has suboptimal activity against APOBEC3 to assess the in-vitro frequency of APOBEC3-induced resistance mutations in reverse transcriptase. To assess the degree of in-vivo G-to-A viral hypermutation, a large amount of data of HIV-1 RT proviral sequences from peripheral blood mononuclear cells (PBMCs) recovered from infected patients under HAART was analyzed. Results:In-vitro replication experiments in cell lines with and without APOBEC3 expression suggest that APOBEC3-driven mutagenesis contributes to the generation of both M184I and E138K within HIV proviral repository in the absence of drug exposure. Additionally, analysis of 601 patients PBMCs sequences revealed that the copresence of mutations E138K and M184I were never detected in nonhypermutated sequences, whereas these mutations were found at a high frequency (24%) in the context of APOBEC3 editing and in the absence of exposure to etravirine–rilpivirine. Conclusion:We demonstrate using in-vitro experiments and analyzing patients PBMCs sequences that M184I and E138K resistance-associated mutations may pre-exist in proviral reservoir at a high frequency prior to drug exposure, as a result of APOBEC3 editing. Thus, incomplete neutralization of one or more APOBEC3 proteins may favor viral escape to rilpivirine-emtricitabine.