Estibaliz Lazaro

Effect of Cytomegalovirus-Induced Immune Response, Self Antigen–Induced Immune Response, and Microbial Translocation on Chronic Immune Activation in Successfully Treated HIV Type 1–Infected Patients: The ANRS CO3 Aquitaine Cohort

We evaluated the impact of cytomegalovirus (CMV)-induced immune responses, autoimmune-induced immune responses, and microbial translocation on immune activation in 191 human immunodeficiency virus type 1-infected patients from the ANRS CO3 Aquitaine Cohort. All enrolled subjects had achieved long-term virological suppression during receipt of combination antiretroviral therapy (cART). HLA-DR(+)/CD38(+) expression was 16.8% among CD8(+) T cells. Independent of age, CD4(+) T-cell count, 16S ribosomal DNA load, and regulatory T-cell count, positive results of Quantiferon CMV analysis (P = .02), positive results of CMV-pp65 enzyme-linked immunosorbent spot analysis (P = .01), positive results of CMV-pp65-specific CD8(+) T-cell analysis (P = .05), and CMV seropositivity (P = .01) were associated with a higher percentage of CD8+ T cells that expressed HLA-DR+/CD38+. Autoimmune response and microbial translocation were not associated with immune activation. Therefore, the CMV-induced immune response seems to be associated with chronic immune activation in cART recipients with sustained virological suppression.

Variable HIV peptide stability in human cytosol is critical to epitope presentation and immune escape.

Induction of virus-specific CD8⁺ T cell responses is critical for the success of vaccines against chronic viral infections. Despite the large number of potential MHC-I-restricted epitopes located in viral proteins, MHC-I-restricted epitope generation is inefficient, and factors defining the production and presentation of MHC-I-restricted viral epitopes are poorly understood. Here, we have demonstrated that the half-lives of HIV-derived peptides in cytosol from primary human cells were highly variable and sequence dependent, and significantly affected the efficiency of cell recognition by CD8⁺ T cells. Furthermore, multiple clinical isolates of HLA-associated HIV epitope variants displayed reduced half-lives relative to consensus sequence. This decreased cytosolic peptide stability diminished epitope presentation and CTL recognition, illustrating a mechanism of immune escape. Chaperone complexes including Hsp90 and histone deacetylase HDAC6 enhanced peptide stability by transient protection from peptidase degradation. Based on empirical results with 166 peptides, we developed a computational approach utilizing a sequence-based algorithm to estimate the cytosolic stability of antigenic peptides. Our results identify sequence motifs able to alter the amount of peptide available for loading onto MHC-I, suggesting potential new strategies to modulate epitope production from vaccine immunogens.

Prevalence and Evolution of Low Frequency HIV Drug Resistance Mutations Detected by Ultra Deep Sequencing in Patients Experiencing First Line Antiretroviral Therapy Failure

Objectives Clinical relevance of low-frequency HIV-1 variants carrying drug resistance associated mutations (DRMs) is still unclear. We aimed to study the prevalence of low-frequency DRMs, detected by Ultra-Deep Sequencing (UDS) before antiretroviral therapy (ART) and at virological failure (VF), in HIV-1 infected patients experiencing VF on first-line ART. Methods Twenty-nine ART-naive patients followed up in the ANRS-CO3 Aquitaine Cohort, having initiated ART between 2000 and 2009 and experiencing VF (2 plasma viral loads (VL) >500 copies/ml or one VL >1000 copies/ml) were included. Reverse transcriptase and protease DRMs were identified using Sanger sequencing (SS) and UDS at baseline (before ART initiation) and VF. Results Additional low-frequency variants with PI-, NNRTI- and NRTI-DRMs were found by UDS at baseline and VF, significantly increasing the number of detected DRMs by 1.35 fold (p<0.0001) compared to SS. These low-frequency DRMs modified ARV susceptibility predictions to the prescribed treatment for 1 patient at baseline, in whom low-frequency DRM was found at high frequency at VF, and 6 patients at VF. DRMs found at VF were rarely detected as low-frequency DRMs prior to treatment. The rare low-frequency NNRTI- and NRTI-DRMs detected at baseline that correlated with the prescribed treatment were most often found at high-frequency at VF. Conclusion Low frequency DRMs detected before ART initiation and at VF in patients experiencing VF on first-line ART can increase the overall burden of resistance to PI, NRTI and NNRTI.

Differential HIV epitope processing in monocytes and CD4 T cells affects cytotoxic T lymphocyte recognition.

The ability of cytotoxic T lymphocytes (CTLs) to clear virus-infected cells is dependent on the presentation of viral peptides processed intracellularly and displayed by major histocompatibility complex class I. Most CTL functional assays use exogenously added peptides, a practice that does not account for the kinetics and quantity of antigenic peptides produced by infectable cells. Here, we examined the relative ability of 2 major human immunodeficiency virus-infectable cell subsets-CD4 T lymphocytes and monocytes-to produce antigenic peptides, using cytosol as a source of peptidases and mass spectrometry to define the degradation products. We show clear subset-specific differences in the kinetics of peptide production and the ability of the peptides produced to sensitize cells for lysis by CTLs, with primary CD4 T lymphocytes having significantly lower proteolytic activity than monocytes. These differences in epitope processing by cell subsets may affect the efficiency of CTL-mediated clearance of infected subsets and contribute to the establishment of chronic infection.

Septic shock sera containing circulating histones induce dendritic cell-regulated necrosis in fatal septic shock patients.

Objectives:Innate immune system alterations, including dendritic cell loss, have been reproducibly observed in patients with septic shock and correlated to adverse outcomes or nosocomial infections. The goal of this study is to better understand the mechanisms behind this observation in order to better assess septic shock pathogenesis. Design:Prospective, controlled experimental study. Setting:Research laboratory at an academic medical center. Subjects:The study enrolled 71 patients, 49 with septic shock and 22 with cardiogenic shock. Seventeen healthy controls served as reference. In vitro monocyte-derived dendritic cells were generated from healthy volunteers. Interventions:Sera were assessed for their ability to promote in vitro dendritic cell death through flow cytometry detection in each group of patients. The percentage of apoptotic or necrotic dendritic cells was evaluated by annexin-V and propidium iodide staining. Measurements and Main Results:We observed that only patients with septic shock and not patients with pure cardiogenic shock were characterized by a rapid and profound loss of circulating dendritic cells. In vitro analysis revealed that sera from patients with septic shock induced higher dendritic cell death compared to normal sera or cardiogenic shock (p < 0.005). Sera from surviving patients induced dendritic cell death through a caspase-dependent apoptotic pathway, whereas sera from nonsurviving patients induced dendritic cell–regulated necrosis. Dendritic cell necrosis was not due to necroptosis but was dependent of the presence of circulating histone. The toxicity of histones toward dendritic cell could be prevented by recombinant human activated protein C. Finally, we observed a direct correlation between the levels of circulating histones in patients and the ability of the sera to promote dendritic cell–regulated necrosis. Conclusions:The study demonstrates a differential mechanism of dendritic cell death in patients with septic shock that is dependent on the severity of the disease.

Interferon α kinoid induces neutralizing anti-interferon α antibodies that decrease the expression of interferon-induced and B cell activation associated transcripts: analysis of extended follow-up data from the interferon α kinoid phase I/II study

Objective. IFN α Kinoid (IFN-K) is a therapeutic vaccine composed of IFNα2b coupled to a carrier protein. In a phase I/II placebo-controlled trial, we observed that IFN-K significantly decreases the IFN gene signature in whole blood RNA samples from SLE patients. Here, we analysed extended follow-up data from IFN-K-treated patients, in order to evaluate persistence of neutralizing anti-IFNα Abs antibodies (Abs), and gene expression profiling. Methods. Serum and whole blood RNA samples were obtained in IFN-K-treated patients included in the follow-up study, in order to determine binding and neutralizing anti-IFNα Ab titres, and perform high-throughput transcriptomic studies. Results. Neutralization studies of 13 IFNα subtypes demonstrated the polyclonal nature of the Ab response induced by IFN-K. Follow-up analyses in six patients confirmed a significant correlation between neutralizing anti-IFNα Ab titres and decrease in IFN scores compared to baseline. These analyses also revealed an inhibitory effect of IFNα blockade on the expression of B cell associated transcripts. Conclusions. IFN-K induces a polyclonal anti-IFNα response that decreases IFN- and B cell-associated transcripts. Trial registration: ClinicalTrials.gov, clinicaltrials.gov, NCT01058343

Association of immune-activation and senescence markers with non-AIDS-defining comorbidities in HIV-suppressed patients.

Objectives:We studied the link between T-cell activation, differentiation and senescence phenotypes and non-AIDS-related comorbidities in HIV-suppressed patients. Design:Patients included in the ANRS CO3 Aquitaine Cohort were consecutively enrolled in this cross-sectional study between October 2011 and May 2013 called Chronic Immune Activation and Senescence (CIADIS) study. Methods:We summarized immune markers [CD4+ and CD8+ activation (DR+), differentiation (naive and terminally differentiated memory T cells), and senescence (CD57+CD28-)] in a weighted immune score by principal component analysis called CIADIS. Previously described Veterans Aging Cohort Study (VACS) index and immune risk profile (IRP) scores were calculated. We used adjusted logistic regression to assess the association between the CIADIS score and the presence of at least three non-AIDS-defining comorbidities. Results:Of 876 patients with an undetectable viral load, 73.4% were men and median age was 50.5 years [interquartile range (IQR) 44.7–56.7 years]. Median CD4+ T-cell count was 579/&mgr;l (IQR 429–759 cells/&mgr;l), and median duration of HIV viral suppression was 5.3 years (IQR 2.3–8.7). The weighted CIADIS score was associated with at least three comorbidities (odds ratio 1.3 for 1 SD more, 95% confidence interval 1.0, 1.6) independently of age, sex, AIDS stage, and the Veterans Aging Cohort Study score. The CIADIS and the immune risk profile scores were significantly associated with at least three comorbidities in adjusted models restricted to patients younger than 60 years. None of the tested scores were associated with at least three comorbidities in patients older than 60 years. Conclusions:The weighted CIADIS score based on activation, senescence, and differentiation markers might help physicians identifying patients at a higher risk for non-AIDS-related comorbidities.

Switch to Rilpivirine/Emtricitabine/Tenofovir Single-Tablet Regimen of Human Immunodeficiency Virus-1 RNA-Suppressed Patients, Agence Nationale de Recherches sur le SIDA et les Hépatites Virales CO3 Aquitaine Cohort, 2012–2014

We evaluated the efficacy and tolerability of a single-tablet regimen strategy in 304 HIV-1 virologically suppressed patients switching to RPV/FTC/TDF for adverse events or treatment simplification. This strategy maintained virologic suppression and was associated with improved tolerability after 12 months follow-up.

A multicentre study of 95 biopsy-proven cases of renal disease in primary Sjögren's syndrome.

Objective. Renal involvement is a rare event during primary SS (pSS). We aimed to describe the clinico-biological and histopathological characteristics of pSS-related nephropathy and its response to treatment. Methods. We conducted a French nationwide, retrospective, multicentre study including pSS patients fulfilling American–European Consensus Group criteria or enlarged American–European Consensus Group criteria, and with biopsy-proven renal involvement. Results. A total of 95 patients were included (median age 49 years). An estimated glomerular filtration rate (eGFR) of <60 ml/min was found in 82/95 patients (86.3%). Renal biopsy demonstrated tubulointerstitial nephritis (TIN) in 93 patients (97.9%), and frequent (75%) plasma cell infiltrates. Glomerular lesions were found in 22 patients (23.2%), mainly related to cryoglobulin. The presence of anti-SSA (76.8%) and anti-SSB (53.8%) antibodies was particularly frequent among patients with TIN and was associated with a worse renal prognosis. Eighty-one patients (85.3%) were treated, with CSs in 80 (98.8%) and immunosuppressive agents (mostly rituximab) in 21 cases (25.9%). Despite marked interstitial fibrosis at initial biopsy, kidney function improved significantly during the 12-month period following diagnosis (final eGFR 49.9 vs 39.8 ml/min/1.73 m2 at baseline, P < 0.001). No proven benefit of immunosuppressive agents over steroid therapy alone was found in this study. Conclusion. Renal involvement of pSS is mostly due to TIN with marked T, B and especially plasma cell infiltration. Renal dysfunction is usually isolated but can be severe. Use of CSs can improve the eGFR, but further studies are needed to define the best therapeutic strategy in this disease.

Immunogenicity and impact on disease activity of influenza and pneumococcal vaccines in systemic lupus erythematosus: a systematic literature review and meta-analysis

OBJECTIVES The aim was to assess the immunogenicity and the impact on disease activity of pneumococcal and influenza vaccines in SLE patients. METHODS We conducted a systematic literature review and meta-analysis of studies comparing the humoral response of either pneumococcal (serotype 23F) or influenza (AH1N1, AH3N2 and B strains) vaccines between SLE patients and healthy controls, assessed by a seroconversion or a seroprotection rate 3-6 weeks after vaccination. The impact on disease activity was assessed by the comparison of the SLEDAI score before and 3-8 weeks after vaccination. Odds ratios (ORs), risk ratios and their 95% CIs were pooled using the generic inverse variance method. RESULTS Twenty studies were included, three for pneumococcal vaccine and 17 for influenza vaccine, gathering 1665 SLE patients and 826 healthy controls. For pneumococcal vaccination, no significant difference was observed, either for seroconversion rate between SLE patients and controls or for the SLEDAI score. For influenza vaccination, the response against AH1N1 was significantly reduced in SLE patients, with a lower rate of seroconversion (OR = 0.38; 95% CI: 0.27, 0.54; P < 0.00001, I(2) = 39%) and seroprotection (OR = 0.36; 95% CI: 0.28, 0.47; P < 0.00001, I(2) = 25%). For AH3N2, only seroprotection rate was significantly lower in SLE patients (OR = 0.26; 95% CI: 0.14, 0.50; P < 0.0001, I(2) = 21%). For B strain, neither seroconversion nor seroprotection rates were significantly different. Influenza vaccine did not modify the SLEDAI score. CONCLUSION The immunogenicity of influenza vaccine in SLE patients depends on the viral strains. A reduced immunogenicity against influenza A is noted, while the immunogenicity against the B strain is preserved. The pneumococcal vaccine against 23F serotype has a preserved immunogenicity. These vaccines have no impact on the SLEDAI score.