Núria Climent
@clinic.cat
AIDS research unit
IDIBAPS/Hospital Clínic i Provincial de Barcelona
RESEARCH INTERESTS
T cell responses, dendritic cells, vaccines, HIV-1
Scopus Publications
Scopus Publications
Lorna Leal, Alberto C. Guardo, Luis M. Bedoya, Cristina Rodríguez de Miguel, Núria Climent, Cristina Rovira, Manuela Beltrán, Josep Llach, Jose Alcamí, Angela D.M. Kashuba,et al.
Mary Ann Liebert Inc
Most of the studies using the colorectal tissue explants challenge model have been conducted after one single-dose and before reaching a steady-state. We consider that longer exposure as in 28-day post-exposure prophylaxis (PEP) course and in an at-risk setting, such as after a sexual risk exposure to HIV could give us valuable information about these drugs. In a substudy we assessed pharmacokinetics, changes on immune system and ex-vivo rectal mucosal susceptibility to HIV-1 infection after taking maraviroc (MVC), raltegravir (RAL) and ritonavir-boosted lopinavir (LPV/r) PEP-based regimens in 30 men who have sex with men. Participants received 28 days of twice-daily MVC (n=11), RAL (n=10) or LPV/r (n=9) all with tenofovir/emtricitabine backbone. Blood, rectal fluid (RF) and rectal tissue (RT) samples were collected at day 7, 28 and 90 after starting PEP. The samples obtained at day 90 were considered baseline. All studied antiretrovirals were quantifiable at 7 and 28 days in all tissues. Activation markers were increased in CD4 mucosal mononuclear cells (MMC) after 28 days of MVC: CD38+ 68.5 vs 85.1, p=0.008 and CD38+DR+ 16.1 vs 26.7, p=0.008. Exposure to MVC at both end-points (7 and 28 days) was associated with significant suppression of HIV-1BAL (p=0.005 and p=0.028) but we did not observe this effect with RAL or LPV/r. Merging together changes in MMC in all arms, we found a positive correlation in the CD8 T-cell lineage between the infectivity at day 7 and activation (CD38+ r=0.43, p=0.025, DR+ r=0.547, p=0.003 and 38+DR+ r=0.526, p=0.05), senescence (CD57+CD28- r=0.479, p=0.012), naïve cells (RA+CCR7+ r=0.484, p=0.01) and CCR5 expression (r=0.593, p=0.001). We conclude that maraviroc in combination with tenofovir/emtricitabine was associated with viral suppression in rectal explants and that overall ex-vivo HIV infectivity correlated with activation and senescence in CD8 mucosal mononuclear cells.
Andrea Rodríguez-Agustín, Víctor Casanova, Judith Grau-Expósito, Sonsoles Sánchez-Palomino, José Alcamí, and Núria Climent
MDPI AG
Tyrosine kinase inhibitors (TKIs) have been extensively used as a treatment for chronic myeloid leukemia (CML). Dasatinib is a broad-spectrum TKI with off-target effects that give it an immunomodulatory capacity resulting in increased innate immune responses against cancerous cells and viral infected cells. Several studies reported that dasatinib expanded memory-like natural killer (NK) cells and γδ T cells that have been related with increased control of CML after treatment withdrawal. In the HIV infection setting, these innate cells are associated with virus control and protection, suggesting that dasatinib could have a potential role in improving both the CML and HIV outcomes. Moreover, dasatinib could also directly induce apoptosis of senescence cells, being a new potential senolytic drug. Here, we review in depth the current knowledge of virological and immunogenetic factors associated with the development of powerful cytotoxic responses associated with this drug. Besides, we will discuss the potential therapeutic role against CML, HIV infection and aging.
Núria Climent, Juan Ambrosioni, Tània González, Cristina Xufré, Maria Casadellà, Marc Noguera-Julian, Roger Paredes, Montserrat Plana, Judith Grau-Expósito, Josep Mallolas,et al.
Elsevier BV
Elena Melendez, Dafni Chondronasiou, Lluc Mosteiro, Jaime Martínez de Villarreal, Marcos Fernández-Alfara, Cian J. Lynch, Dirk Grimm, Francisco X. Real, José Alcamí, Núria Climent,et al.
The Company of Biologists
ABSTRACT The ectopic expression of the transcription factors OCT4, SOX2, KLF4 and MYC (OSKM) enables reprogramming of differentiated cells into pluripotent embryonic stem cells. Methods based on partial and reversible in vivo reprogramming are a promising strategy for tissue regeneration and rejuvenation. However, little is known about the barriers that impair reprogramming in an in vivo context. We report that natural killer (NK) cells significantly limit reprogramming, both in vitro and in vivo. Cells and tissues in the intermediate states of reprogramming upregulate the expression of NK-activating ligands, such as MULT1 and ICAM1. NK cells recognize and kill partially reprogrammed cells in a degranulation-dependent manner. Importantly, in vivo partial reprogramming is strongly reduced by adoptive transfer of NK cells, whereas it is significantly increased by their depletion. Notably, in the absence of NK cells, the pancreatic organoids derived from OSKM-expressing mice are remarkably large, suggesting that ablating NK surveillance favours the acquisition of progenitor-like properties. We conclude that NK cells pose an important barrier for in vivo reprogramming, and speculate that this concept may apply to other contexts of transient cellular plasticity.
Lorna Leal, Elvira Couto, Sonsoles Sánchez-Palomino, Núria Climent, Irene Fernández, Laia Miralles, Yolanda Romero, Tania González, Maria José Maleno, Blanca Paño,et al.
Frontiers Media SA
IntroductionFunctional cure has been proposed as an alternative to lifelong antiretroviral therapy and therapeutic vaccines represent one of the most promising approaches.Materials and MethodsWe conducted a double-blind randomized placebo-controlled clinical trial to evaluate the safety, immunogenicity, and effect on viral dynamics of a therapeutic vaccine produced with monocyte-derived dendritic cells (MD-DC) loaded with a high dose of heat-inactivated autologous (HIA) HIV-1 in combination with pegylated interferon alpha 2a (IFNα-2a) in people with chronic HIV-1.ResultsTwenty-nine male individuals on successful ART and with CD4+ ≥450 cells/mm3 were randomized 1:1:1:1 to receive three ultrasound-guided inguinal intranodal immunizations, one every 2 weeks: (1) vaccine ~107 MD-DC pulsed with HIA-HIV-1 (1010 HIV RNA copies) (n = 8); (2) vaccine plus three doses of 180 mcg IFNα-2a at weeks 4–6 (n = 6); (3) placebo = saline (n = 7); and (4) placebo plus three doses of 180 mcg IFNα-2a (n = 8). Thereafter, treatment was interrupted (ATI). Vaccines, IFNα-2a, and the administration procedures were safe and well tolerated. All patients’ viral load rebounded during the 12-week ATI period. According to groups, changes in viral set-point between pre-ART and during ATI were not significant. When comparing all groups, there was a tendency in changes in viral set-point between the vaccine group vs. vaccine + IFNα-2a group (>0.5log10p = 0.05). HIV-1-specific T-cell responses (IFN-ƴ Elispot) were higher at baseline in placebo than in the vaccine group (2,259 ± 535 vs. 900 ± 200 SFC/106 PBMC, p = 0.028). A significant difference in the change of specific T-cell responses was only observed at week 4 between vaccine and placebo groups (694 ± 327 vs. 1,718 ± 282 SFC/106 PBMC, p = 0.04). No effect on T-cell responses or changes in viral reservoir were observed after INFα-2a administration.DiscussionResults from this study show that intranodally administered DC therapeutic vaccine in combination with IFNα-2a was safe and well-tolerated but had a minimal impact on viral dynamics in HIV-1 chronic infected participants.Clinical Trial Registration(www.ClinicalTrials.gov), identifier NCT02767193
Alexander Botvinnik, Pushkar Shivam, Yoav Smith, Gunjan Sharma, Udy Olshevsky, Ofra Moshel, Zakhariya Manevitch, Nuria Climent, Harold Oliva, Elena Britan‐Rosich,et al.
Wiley
Human apolipoprotein B mRNA editing enzyme, catalytic polypeptide-like 3G (hA3G), a member of the APOBEC family, was described as an anti-HIV-1 restriction factor, deaminating reverse transcripts of the HIV-1 genome. Several types of cancer cells that express high levels of A3G, such as diffuse large B-cell lymphoma cells and glioblastomas, show enhanced cell survival after ionizing radiation (IR) and chemotherapy treatments. Previously, we showed that hA3G promotes (DNA) double-strand breaks repair in cultured cells and it rescues transgenic mice from lethal IR dose. Here we show that A3G rescues cells from the detrimental effects of DNA damage induced by ultraviolet radiation (UV) and by combined bromodeoxyuridine and UV treatments. The combined treatments stimulate the synthesis of cellular proteins, which are exclusively associated with A3G expression. These proteins participate mainly in nucleotide excision repair and homologous recombination DNA repair pathways. Our results implicate A3G inhibition as a potential strategy for increasing tumor cells sensitivity to genotoxic treatments.
Lorena Vigón, Sara Rodríguez-Mora, Alejandro Luna, Virginia Sandonís, Elena Mateos, Guiomar Bautista, Juan Luis Steegmann, Nuria Climent, Montserrat Plana, Pilar Pérez-Romero,et al.
Elsevier BV
Csaba Fehér, Montserrat Plana, Alberto Crespo Guardo, Nuria Climent, Lorna Leal, Ainoa Ugarte, Irene Fernández, María F. Etcheverry, Josep M. Gatell, Sonsoles Sánchez-Palomino,et al.
Ovid Technologies (Wolters Kluwer Health)
OBJECTIVES
To construct a classifier that predicts the probability of viral control after analytical antiretroviral treatment interruptions (ATI) in HIV research trials.
METHODS
Participants of a dendritic cell-based therapeutic vaccine trial (DCV2) constituted the derivation cohort. One of the primary end-points of DCV2 was the drop of viral load (VL) set point after 12 weeks of ATI (delta VL12). We classified cases as "controllers" (delta VL12 >1 log10 copies/mL, n=12) or"non-controllers" (delta VL12 < 0.5 log10 copies/mL, n= 10), and compared 190 variables (clinical data, lymphocyte subsets, inflammatory markers, viral reservoir, ELISPOT, and lymphoproliferative responses) between the two groups. Naïve Bayes classifiers were built from combinations of significant variables. The best model was subsequently validated on an independent cohort.
RESULTS
Controllers had significantly higher pre-ART VL (110250 [IQR 71968- 275750] vs. 28600 [IQR 18737-39365] copies/mL, p=0.003) and significantly lower proportion of some T lymphocyte subsets than non-controllers: pre-vaccination CD4+CD45RA+RO+ (1.72% vs. 7.47%, p=0.036), CD8+CD45RA+RO+ (7.92% vs. 15.69%, p=0.017), CD4+CCR5+ (4.25% vs. 7.40%, p=0.011), and CD8+CCR5+ (14.53% vs. 27.30%, p=0.043), and post-vaccination CD4+CXCR4+ (12.44% vs. 22.80%, p=0.021). The classifier based on pre-ART VL and pre-vaccine CD8+CD45RA+RO+ T cells was the best predictive model (overall accuracy: 91%). In an independent validation cohort of 107 ATI episodes, the model correctly identified non-responders (negative predictive value=94%), while it failed to identify responders (positive predictive value=20%).
CONCLUSIONS
Our simple classifier could correctly classify those patients with low probability of control of VL after ATI. These data could be helpful for HIV research trial design.
Florencia Etcheverry-Rufino, Constanza Lucero, María López-Cerón, Yoko Aleñar-Gelabert, Irene Fernández, Ainoa Ugarte, Manel E. Bargalló, Martin Goetz, Luis Veloza, Josep A. Bombí,et al.
Ovid Technologies (Wolters Kluwer Health)
Csaba Fehér, Lorna Leal, Montserrat Plana, Nuria Climent, Alberto Crespo Guardo, Esteban Martínez, Pedro Castro, Vicens Díaz-Brito, Beatriz Mothe, Juan Carlos López Bernaldo De Quirós,et al.
Oxford University Press (OUP)
Abstract Background Analytical treatment interruptions (ATI) are essential in research on HIV cure. However, the heterogeneity of virological outcome measures used in different trials hinders the interpretation of the efficacy of different strategies. Methods A retrospective analysis of viral load (VL) evolution in 334 ATI episodes in chronic HIV-1 infected patients collected from 11 prospective studies. Quantitative [baseline VL, set point, delta set point, VL and delta VL at given weeks after ATI, peak VL, delta peak VL, and area under the rebound curve], and temporal parameters [time to rebound (TtR), set point, peak, and certain absolute and relative VL thresholds] were described. Pairwise correlations between parameters were analyzed, and potential confounding factors (sex, age, time of known HIV infection, time on ART, and immunological interventions) were evaluated. Results Set point was lower than baseline VL (median delta set point -0.26. p< 0.001). This difference was >1 log10 copies/mL in 13.9% of the cases. Median TtR was 2 weeks; no patients had undetectable VL at week 12. Median time to set point was 8 weeks: by week 12, 97.4% of the patients had reached the set point. TtR and baseline VL were correlated with most temporal and quantitative parameters. The variables independently associated with TtR were baseline VL and the use of immunological interventions. Conclusions TtR could be an optimal surrogate marker of response in HIV cure strategies. Our results underline the importance of taking into account baseline VL and other confounding factors in the design and interpretation of these studies.
María J. Ruiz-de-León, María A. Jiménez-Sousa, Santiago Moreno, Marcial García, Mónica Gutiérrez-Rivas, Agathe León, Marta Montero-Alonso, Juan González-García, Salvador Resino, Norma Rallón,et al.
Elsevier BV
Exosome-derived miR-21 was independently associated with CD4 T cell decline in HIV-1-infected elite controllers (OR 0.369, 95% CI 0.137-0.994, p = 0.049). Also, a negative correlation between miR-21 expression and MCP-1 level was found (r = -0.649, p = 0.020), while no correlation between soluble biomarkers or cellular immune activation was found.
Núria Climent and Montserrat Plana
Frontiers Media SA
Tyrosine kinase inhibitors (TKIs) of aberrant tyrosine kinase (TK) activity have been widely used to treat chronic myeloid leukemia (CML) for decades in clinic. An area of growing interest is the reported ability of TKIs to induce immunomodulatory effects with anti-tumor and anti-viral activity, which appears to be mediated by directly or indirectly acting on immune cells. In selected cases of patients with CML, TKI treatment may be interrupted and a non-drug remission may be observed. In these patients, an immune mechanism of increased anti-tumor cytotoxic activity induced by chronic administration of TKIs has been suggested. TKIs increase some populations of natural killer (NK), NK-LGL, and T-LGLs cells especially in dasatinib treated CML patients infected with cytomegalovirus (CMV). In addition, dasatinib increases responses against CMV and is able to inhibit HIV replication in vitro. Recent studies suggest that subclinical reactivation of CMV could drive expansion of specific subsets of NK- and T-cells with both anti-tumoral and anti-viral function. Therefore, the underlying mechanisms implicated in the expansion of this increased anti-tumor and anti-viral cytotoxic activity induced by TKIs could be a new therapeutic approach to take into account against cancer and viral infections such as HIV-1 infection. The present review will briefly summarize the immunomodulatory effects of TKIs on T cells, NKs, and B cells. Therapeutic implications for modulating immunity against cancer and viral infections and critical open questions are also discussed.
Mercedes Bermejo, Juan Ambrosioni, Guiomar Bautista, Núria Climent, Elena Mateos, Cristina Rovira, Sara Rodríguez-Mora, María Rosa López-Huertas, Valentín García-Gutiérrez, Juan Luis Steegmann,et al.
Elsevier BV
Graphical abstract Mechanismsof actionof different TKIs for avoiding HIV‐1 infection of CD4+ T lymphocytes. 1) Preventing SAMHD1 phosphorylation; 2) impeding TCR‐mediated activation; 3) avoiding proviral reactivation; and 4) interfering with reservoir reseeding. Figure. No Caption available. Abstract Current antiretroviral treatment (ART) may control HIV‐1 replication but it cannot cure the infection due to the formation of a reservoir of latently infected cells. CD4+ T cell activation during HIV‐1 infection eliminates the antiviral function of the restriction factor SAMHD1, allowing proviral integration and the reservoir establishment. The role of tyrosine kinases during T‐cell activation is essential for these processes. Therefore, the inhibition of tyrosine kinases could control HIV‐1 infection and restrict the formation of the reservoir. A family of tyrosine kinase inhibitors (TKIs) is successfully used in clinic for treating chronic myeloid leukemia (CML). The safety and efficacy against HIV‐1 infection of five TKIs was assayed in PBMCs isolated from CML patients on prolonged treatment with these drugs that were infected ex vivo with HIV‐1. We determined that the most potent and safe TKI against HIV‐1 infection was dasatinib, which preserved SAMHD1 antiviral function and avoid T‐cell activation through TCR engagement and homeostatic cytokines. Imatinib and nilotinib showed lower potency and bosutinib was quite toxic in vitro. Ponatinib presented similar profile to dasatinib but as it has been associated with higher incidence of arterial ischemic events, dasatinib would be the better choice of TKI to be used as adjuvant of ART in order to avoid the establishment and replenishment of HIV‐1 reservoir and move forward towards an HIV cure.
Núria Climent, Isabel García, Marco Marradi, Fabrizio Chiodo, Laia Miralles, María José Maleno, José María Gatell, Felipe García, Soledad Penadés, and Montserrat Plana
Elsevier BV
Gold nanoparticles (GNPs) decorated with glycans ameliorate dendritic cells (DC) uptake, antigen-presentation and T-cells cross-talk, which are important aspects in vaccine design. GNPs allow for high antigen loading, DC targeting, lack of toxicity and are straightforward prepared and easy to handle. The present study aimed to assess the capacity of DC to process and present HIV-1-peptides loaded onto GNPs bearing high-mannoside-type oligosaccharides (P1@HM) to autologous T-cells from HIV-1 patients. The results showed that P1@HM increased HIV-specific CD4+ and CD8+ T-cell proliferation and induced highly functional cytokine secretion compared with HIV-peptides alone. P1@HM elicits a highly efficient secretion of pro-TH1 cytokines and chemokines, a moderate production of pro-TH2 and significant higher secretion of pro-inflammatory cytokines such as TNF-α and IL-1β. Thus, co-delivery of HIV-1 antigens and HM by GNPs is an excellent vaccine delivery system inducing HIV-specific cellular immune responses in HIV+ patients, being a promising approach to improve anti-HIV-1 vaccines.
Marta Montserrat, Montserrat Plana, Alberto C. Guardo, Cristina Andrés, Nuria Climent, Teresa Gallart, Lorna Leal, Josep M. Gatell, Sonsoles Sánchez-Palomino, and Felipe García
Ovid Technologies (Wolters Kluwer Health)
&NA; We assessed if the increase on viral reservoir after long-term antiretroviral therapy (ART) interruption (ATI) is reversible upon ART resumption in chronic HIV-1 infected patients. Total HIV-1 DNA increased to pre-ART levels after 48 weeks of ATI to return to pre-ATI levels after 104 weeks of ART resumption. Conversely, integrated HIV-1 DNA remained elevated after ART reinitiation. These data suggest that the increase in reservoir after long-term ART discontinuation might not be reversible at midterm.
Joana Vitallé, Olatz Zenarruzabeitia, Iñigo Terrén, Montserrat Plana, Alberto C. Guardo, Lorna Leal, José Peña, Felipe García, and Francisco Borrego
Frontiers Media SA
A modified vaccinia Ankara-based HIV-1 vaccine clade B (MVA-B) has been tested for safety and immunogenicity in low-risk human immunodeficiency virus (HIV)-uninfected individuals and as a therapeutic vaccine in HIV-1-infected individuals on combined antiretroviral therapy (cART). As a therapeutic vaccine, MVA-B was safe and broadly immunogenic; however, patients still showed a viral rebound upon treatment interruption. Monocytes are an important part of the viral reservoir and several studies suggest that they are partly responsible for the chronic inflammation observed in cART-treated HIV-infected people. The CD300 family of receptors has an important role in several diseases, including viral infections. Monocytes express CD300a, c, e, and f molecules and lipopolysaccharide (LPS) and other stimuli regulate their expression. However, the expression and function of CD300 receptors on monocytes in HIV infection is still unknown. In this work, we investigated for the first time the expression of CD300 molecules and the cytokine production in response to LPS on monocytes from HIV-1-infected patients before and after vaccination with MVA-B. Our results showed that CD300 receptors expression on monocytes from HIV-1-infected patients correlates with markers of HIV infection progression and immune inflammation. Specifically, we observed a positive correlation between the expression of CD300e and CD300f receptors on monocytes with the number of CD4+ T cells of HIV-1-infected patients before vaccination. We also saw a positive correlation between the expression of the inhibitory receptor CD300f and the expression of CD163 on monocytes from HIV-1-infected individuals before and after vaccination. In addition, monocytes exhibited a higher cytokine production in response to LPS after vaccination, almost at the same levels of monocytes from healthy donors. Furthermore, we also described a correlation in the expression of CD300e and CD300f receptors with TNF-α production in response to LPS, only in monocytes of HIV-1-infected patients before vaccination. Altogether, our results describe the impact of HIV-1 and of the MVA-B vaccine in cytokine production and monocytes phenotype.
Esther Carrasco, Cristina Escoda-Ferran, Núria Climent, Cristina Miró-Julià, Inês T. Simões, Mario Martínez-Florensa, Adelaida Sarukhan, Esther Carreras, and Francisco Lozano
Frontiers Media SA
Available evidence indicates that the CD6 lymphocyte surface receptor is involved in T-cell developmental and activation processes, by facilitating cell-to-cell adhesive contacts with antigen-presenting cells and likely modulating T-cell receptor (TCR) signaling. Here, we show that in vitro activation of human T cells under different TCR-ligation conditions leads to surface downregulation of CD6 expression. This phenomenon was (i) concomitant to increased levels of soluble CD6 (sCD6) in culture supernatants, (ii) partially reverted by protease inhibitors, (iii) not associated to CD6 mRNA down-regulation, and (iv) reversible by stimulus removal. CD6 down-modulation inversely correlated with the upregulation of CD25 in both FoxP3− (Tact) and FoxP3+ (Treg) T-cell subsets. Furthermore, ex vivo analysis of peripheral CD4+ and CD8+ T cells with activated (CD25+) or effector memory (effector memory T cell, CD45RA−CCR7−) phenotype present lower CD6 levels than their naïve or central memory (central memory T cell, CD45RA−CCR7+) counterparts. CD6lo/− T cells resulting from in vitro T-cell activation show higher apoptosis and lower proliferation levels than CD6hi T cells, supporting the relevance of CD6 in the induction of proper T-cell proliferative responses and resistance to apoptosis. Accordingly, CD6 transfectants also showed higher viability when exposed to TCR-independent apoptosis-inducing conditions in comparison with untransfected cells. Taken together, these results provide insight into the origin of sCD6 and the previously reported circulating CD6-negative T-cell subset in humans, as well as into the functional consequences of CD6 down-modulation on ongoing T-cell responses, which includes sensitization to apoptotic events and attenuation of T-cell proliferative responses.
Harold Oliva, Rodrigo Pacheco, José M Martinez‐Navio, Marta Rodríguez‐García, Mar Naranjo‐Gómez, Núria Climent, Carolina Prado, Cristina Gil, Montserrat Plana, Felipe García,et al.
Wiley
APOBEC3G (apolipoprotein B mRNA editing enzyme catalytic polypeptide‐like 3G; A3G) is an innate defense protein showing activity against retroviruses and retrotransposons. Activated CD4+ T cells are highly permissive for HIV‐1 replication, whereas resting CD4+ T cells are refractory. Dendritic cells (DCs), especially mature DCs, are also refractory. We investigated whether these differences could be related to a differential A3G expression and/or subcellular distribution. We found that A3G mRNA and protein expression is very low in resting CD4+ T cells and immature DCs, but increases strongly following T‐cell activation and DC maturation. The Apo‐7 anti‐A3G monoclonal antibody (mAb), which was specifically developed, confirmed these differences at the protein level and disclosed that A3G is mainly cytoplasmic in resting CD4+ T cells and immature DCs. Nevertheless, A3G translocates to the nucleus in activated‐proliferating CD4+ T cells, yet remaining cytoplasmic in matured DCs, a finding confirmed by immunoblotting analysis of cytoplasmic and nuclear fractions. Apo‐7 mAb was able to immunoprecipitate endogenous A3G allowing to detect complexes with numerous proteins in activated‐proliferating but not in resting CD4+ T cells. The results show for the first time the nuclear translocation of A3G in activated‐proliferating CD4+ T cells.
Lander Egaña-Gorroño, Alberto C. Guardo, Manel E. Bargalló, Evarist Planet, Elisenda Vilaplana, Tuixent Escribà, Iñaki Pérez, Josep Maria Gatell, Felipe García, Mireia Arnedo,et al.
Public Library of Science (PLoS)
Background The relationship between host microRNAs (miRNA), viral control and immune response has not yet been elucidated in the field of HIV. The aim of this study was to assess the differential miRNA profile in CD8+ T-cells between HIV-infected individuals who differ in terms of viral replication control and immune response. Methods miRNA profile from resting and CD3/CD28-stimulated CD8+ T-cells from uninfected individuals (HIV-, n = 11), Elite Controllers (EC, n = 15), Viremic Controllers (VC, n = 15), Viremic Progressors (VP, n = 13) and HIV-infected patients on therapy (ART, n = 14) was assessed using Affymetrix miRNA 3.1 arrays. After background correction, quantile normalization and median polish summarization, normalized data were fit to a linear model. The analysis comprised: resting samples between groups; stimulated samples between groups; and stimulated versus resting samples within each group. Enrichment analyses of the putative target genes were perfomed using bioinformatic algorithms. Results A downregulated miRNA pattern was observed when resting samples from all infected groups were compared to HIV-. A miRNA downregulation was also observed when stimulated samples from EC, ART and HIV- groups were compared to VP, being hsa-miR-4492 the most downregulated. Although a preferential miRNA downregulation was observed when stimulated samples were compared to the respective resting samples, VP presented a differential miRNA expression pattern. In fact, hsa-miR-155 and hsa-miR-181a were downregulated in VP whereas in the other groups, either an upregulation or no differences were observed after stimulation, respectively. Overall, functional enrichment analysis revealed that the predicted target genes were involved in signal transduction pathways, metabolic regulation, apoptosis, and immune response. Conclusions Resting CD8+ T-cells do not exhibit a differential miRNA expression between HIV-infected individuals but they do differ from non-infected individuals. Moreover, a specific miRNA pattern is present in stimulated CD8+ T-cells from VP which could reflect a detrimental pattern in terms of CD8+ T-cell immune response.
Mercedes Bermejo, María Rosa López-Huertas, Javier García-Pérez, Núria Climent, Benjamin Descours, Juan Ambrosioni, Elena Mateos, Sara Rodríguez-Mora, Lucía Rus-Bercial, Monsef Benkirane,et al.
Elsevier BV
Massive activation of infected CD4+ T cells during acute HIV-1 infection leads to reservoir seeding and T-cell destruction. During T-cell activation, the antiviral effect of the innate factor SAMHD1 is neutralized through phosphorylation at T592, allowing HIV-1 infection. Dasatinib, a tyrosine kinase inhibitor currently used for treating chronic myeloid leukemia, has been described to control HIV-1 replication through its negative effect on T-cell proliferation and viral entry. We demonstrate that Dasatinib can actually interfere with SAMHD1 phosphorylation in human peripheral blood lymphocytes, preserving its antiviral activity against HIV-1. Dasatinib prevented SAMHD1 phosphorylation in vitro and ex vivo, impairing HIV-1 reverse transcription and proviral integration. This was the major mechanism of action because the presence of Vpx, which degrades SAMHD1, in HIV-1 virions impeded the inhibitory effect of Dasatinib on HIV-1 replication. In fact, infection with VSV-pseudotyped HIV-1 virions and fusion of BlaM-Vpr-containing HIV-1 viruses with activated PBMCs in the presence of Dasatinib suggested that Dasatinib was not acting at fusion level. Finally, PBMCs from patients on chronic treatment with Dasatinib showed a lower level of SAMHD1 phosphorylation in response to activating stimuli and low susceptibility to HIV-1 infection ex vivo. Consequently, Dasatinib is a compound currently used in clinic that preserves the antiviral function of SAMHD1. Using Dasatinib as adjuvant of antiretroviral therapy during early primary HIV-1 infection would contribute to reduce viral replication and spread, prevent reservoir seeding, and preserve CD4 counts and CTL responses. These events would create a more favorable virologic and immunologic environment for future interventional studies aiming at HIV-1 eradication.
Isaac Naval-Macabuhay, Víctor Casanova, Gemma Navarro, Felipe García, Agathe León, Laia Miralles, Cristina Rovira, José M. Martinez-Navio, Teresa Gallart, Josefa Mallol,et al.
Wiley
Regulatory T cells have an important role in immune suppression during HIV‐1 infection. As regulatory T cells produce the immunomodulatory molecule adenosine, our aim here was to assess the potential of adenosine removal to revert the suppression of anti‐HIV responses exerted by regulatory T cells. The experimental setup consisted of ex vivo cocultures of T and dendritic cells, to which adenosine deaminase, an enzyme that hydrolyzes adenosine, was added. In cells from healthy individuals, adenosine hydrolysis decreased CD4+CD25hi regulatory T cells. Addition of 5′‐N‐ethylcarboxamidoadenosine, an adenosine receptor agonist, significantly decreased CD4+CD25lo cells, confirming a modulatory role of adenosine acting via adenosine receptors. In autologous cocultures of T cells with HIV‐1‐pulsed dendritic cells, addition of adenosine deaminase led to a significant decrease of HIV‐1‐induced CD4+CD25hi forkhead box p3+ cells and to a significant enhancement of the HIV‐1‐specific CD4+ responder T cells. An increase in the effector response was confirmed by the enhanced production of CD4+ and CD8+ CD25−CD45RO+ memory cell generation and secretion of Th1 cytokines, including IFN‐γ and IL‐15 and chemokines MIP‐1α/CCL3, MIP‐1β/CCL4, and RANTES/CCL5. These ex vivo results show, in a physiologically relevant model, that adenosine deaminase is able to enhance HIV‐1 effector responses markedly. The possibility to revert regulatory T cell‐mediated inhibition of immune responses by use of adenosine deaminase, an enzyme that hydrolyzes adenosine, merits attention for restoring T lymphocyte function in HIV‐1 infection.
Vincent Pavot, Nuria Climent, Nicolas Rochereau, Felipe Garcia, Christian Genin, Gérard Tiraby, Fabienne Vernejoul, Eric Perouzel, Thierry Lioux, Bernard Verrier,et al.
Elsevier BV
Mucosal surfaces are a major portal of entry for many pathogens that are the cause of infectious diseases. Therefore, effective vaccines that induce a protective immune response at these sites are much needed. However, despite early success with the live attenuated oral polio vaccine over 50 years ago, only a few new mucosal vaccines have been subsequently licensed. Development of new adjuvants, comprising antigen delivery platforms and immunostimulatory molecules, are critical for the successful development of new mucosal vaccines. Among them, biodegradable nanoparticle delivery systems are promising and NOD-like receptors are considered as potential new targets for immunostimulatory molecules. In this work, different NOD1 and NOD2 ligands were encapsulated in polylactic acid (PLA) nanoparticles, coated with HIV-1 gag p24 antigen. We showed that these new formulations are able to induce proliferation of HIV-specific T cells from HIV(+) individuals as well as autophagy. In vivo, these formulations highly enhanced p24-specific systemic and mucosal immune responses in mice not only after mucosal administration but also after immunization via the parenteral route. Our results provide a rational approach for combining nanosized particulate carriers and encapsulated NOD receptor ligands as potent synergistic tools for induction of specific mucosal immunity.
Alberto C. Guardo, Marta Ruiz-Riol, Emma Fernández, Maria J. Maleno, Manel E. Bargalló, Agathe León, Nuria Climent, Felipe García, Jose M. Gatell, Christian Brander,et al.
Ovid Technologies (Wolters Kluwer Health)
Background:Although virus-specific responses are rarely detected by conventional approaches, we report here the detection of T-cell responses in HIV-exposed seronegative (HESN) patients by two distinct assays. Methods:HIV-specific T-cell responses were analyzed by enzyme-linked immunospot in peripheral blood mononuclear cells from HESN patients after a 48-h co-culture with boosted dendritic cells. Additionally, a boosted flow cytometry approach was used to capture antiviral T-cell responses. Host genetic factors and T-cell activation were also analyzed to assess their implication on HIV exposure. Results:Of the 45 HESN individuals tested, up to 11 (24.4%) showed at least one response to peptide pools covering HIV Gag and Nef. A positive correlation was observed between the intensity (P = 0.0022) and magnitude (P = 0.0174) of the response detected in the HESN, and the viral load of the HIV-positive partner. Moreover, the result from the boosted flow and cytomix analyses showed a dominant Th1-like response pattern against HIV antigens, especially in CD8+ T-cell populations. Conclusions:The combined use of our boosted dendritic cell technique with a boosted flow cytometric approach allows us both to detect specific HIV-positive responses in a higher percentage of HESN patients and to define specific effector function profiles. This study contributes to a better understanding of resistance to HIV infection.
Cristina Andrés, Montserrat Plana, Alberto C. Guardo, Carmen Alvarez-Fernández, Nuria Climent, Teresa Gallart, Agathe León, Bonaventura Clotet, Brigitte Autran, Nicolas Chomont,et al.
American Society for Microbiology
ABSTRACT HIV-1-specific immune responses induced by a dendritic cell (DC)-based therapeutic vaccine might have some effect on the viral reservoir. Patients on combination antiretroviral therapy (cART) were randomized to receive DCs pulsed with autologous HIV-1 ( n = 24) (DC-HIV-1) or nonpulsed DCs ( n = 12) (DC-control). We measured the levels of total and integrated HIV-1 DNA in CD4 T cells isolated from these patients at 6 time points: before any cART; before the first cART interruption, which was at 56 weeks before the first immunization to isolate virus for pulsing DCs; before and after vaccinations (VAC1 and VAC2); and at weeks 12 and 48 after the second cART interruption. The vaccinations did not influence HIV-1 DNA levels in vaccinated subjects. After the cART interruption at week 12 postvaccination, while total HIV-1 DNA increased significantly in both arms, integrated HIV-1 DNA did not change in vaccinees (mean of 1.8 log 10 to 1.9 copies/10 6 CD4 T cells, P = 0.22) and did increase in controls (mean of 1.8 log 10 to 2.1 copies/10 6 CD4 T cells, P = 0.02) ( P = 0.03 for the difference between groups). However, this lack of increase of integrated HIV-1 DNA observed in the DC-HIV-1 group was transient, and at week 48 after cART interruption, no differences were observed between the groups. The HIV-1-specific T cell responses at the VAC2 time point were inversely correlated with the total and integrated HIV-1 DNA levels after cART interruption in vaccinees ( r [Pearson's correlation coefficient] = −0.69, P = 0.002, and r = −0.82, P < 0.0001, respectively). No correlations were found in controls. HIV-1-specific T cell immune responses elicited by DC therapeutic vaccines drive changes in HIV-1 DNA after vaccination and cART interruption. (This study has been registered at ClinicalTrials.gov under registration no. NCT00402142.) IMPORTANCE There is an intense interest in developing strategies to target HIV-1 reservoirs as they create barriers to curing the disease. The development of therapeutic vaccines aimed at enhancing immune-mediated clearance of virus-producing cells is of high priority. Few therapeutic vaccine clinical trials have investigated the role of therapeutic vaccines as a strategy to safely eliminate or control viral reservoirs. We recently reported that a dendritic cell-based therapeutic vaccine was able to significantly decrease the viral set point in vaccinated patients, with a concomitant increase in HIV-1-specific T cell responses. The HIV-1-specific T cell immune responses elicited by this therapeutic dendritic cell vaccine drove changes in the viral reservoir after vaccinations and significantly delayed the replenishment of integrated HIV-1 DNA after cART interruption. These data help in understanding how an immunization could shift the virus-host balance and are instrumental for better design of strategies to reach a functional cure of HIV-1 infection.
Enrique Vacas-Córdoba, Núria Climent, Francisco J De La Mata, Montserrat Plana, Rafael Gómez, Marjorie Pion, Felipe García, and Maria Ángeles Muñoz-Fernández
Future Medicine Ltd
Although the antiretroviral therapy has led to a long-term control of HIV-1, it does not cure the disease. Therefore, several strategies are being explored to develop an effective HIV vaccine, such as the use of dendritic cells (DCs). DC-based immunotherapies bear different limitations, but one of the most critical point is the antigen loading into DCs. Nanotechnology offers new tools to overcome these constraints. Dendrimers have been proposed as carriers for targeted delivery of HIV antigens in DCs. These nanosystems can release the antigens in a controlled manner leading to a more potent specific immune response. This review focuses on the first steps for clinical development of dendrimers to assess their safety and potential use in DC-based immunotherapies against HIV.