Novel structurally related compounds reactivate latent HIV-1 in a bcl-2-transduced primary CD4+ T cell model without inducing global T cell activation

Background: The latent reservoir of HIV-1 in resting memory CD4+ T cells is a major barrier to curing HIV-1 infection. Eradication strategies involve reactivation of this latent reservoir; however, agents that reactivate latent HIV-1 through non-specific T cell activation are toxic. Methods: Using latently infected Bcl-2-transduced primary CD4+ T cells, we screened the MicroSource Spectrum library for compounds that reactivate latent HIV-1 without global T cell activation. Based on the structures of the initial hits, we assembled 50 derivatives from commercial sources and mostly by synthesis. The doseresponse relationships of these derivatives were established in a primary cell model. Activities were confirmed with another model of latency (J-Lat). Cellular toxicity and cytokine secretion were tested using freshly isolated human CD4+ T cells. Results: We identified two classes of quinolines that reactivate latent HIV-1. Class I compounds are the Mannich adducts of 5-chloroquinolin-8-ol. Class II compounds are quinolin-8-yl carbamates. Most EC 50 values were in the 0.5 -10 mM range. HIV-1 reactivation ranged from 25% to 70% for anti-CD3+ anti-CD28 co-stimulation. All quinolin-8-ol derivatives that reactivate latent HIV-1 follow Lipinski's Rule of Five, and most follow the stricter rule of three for leads. After 48 h of treatment, none of the analogues induced detectable cytokine secretion in primary resting CD4+ T cells. Conclusions: We discovered a group of quinolin-8-ol derivatives that can induce latent HIV-1 in a primary cell model without causing global T cell activation. This work expands the number of latency-reversing agents and provides new possible scaffolds for further drug development research

Histone deacetylases in viral infections

Chromatin remodeling and gene expression are regulated by histone deacetylases (HDACs) that condense the chromatin structure by deacetylating histones. HDACs comprise a group of enzymes that are responsible for the regulation of both cellular and viral genes at the transcriptional level. In mammals, a total of 18 HDACs have been identified and grouped into four classes, i.e., class I (HDACs 1, 2, 3, 8), class II (HDACs 4, 5, 6, 7, 9, 10), class III (Sirt1–Sirt7), and class IV (HDAC11). We review here the role of HDACs on viral replication and how HDAC inhibitors could potentially be used as new therapeutic tools in several viral infections

Resting Regulatory CD4 T Cells: A Site of HIV Persistence in Patients on Long-Term Effective Antiretroviral Therapy

BACKGROUND: In HIV-infected patients on long-term HAART, virus persistence in resting long-lived CD4 T cells is a major barrier to curing the infection. Cell quiescence, by favouring HIV latency, reduces the risk of recognition and cell destruction by cytotoxic lymphocytes. Several cell-activation-based approaches have been proposed to disrupt cell quiescence and then virus latency, but these approaches have not eradicated the virus. CD4+CD25+ regulatory T cells (Tregs) are a CD4+ T-cell subset with particular activation properties. We investigated the role of these cells in virus persistence in patients on long-term HAART. METHODOLOGY/PRINCIPAL FINDINGS: We found evidence of infection of resting Tregs (HLADR(-)CD69(-)CD25(hi)FoxP3+CD4+ T cells) purified from patients on prolonged HAART. HIV DNA harbouring cells appear more abundant in the Treg subset than in non-Tregs. The half-life of the Treg reservoir was estimated at 20 months. Since Tregs from patients on prolonged HAART showed hyporesponsiveness to cell activation and inhibition of HIV-specific cytotoxic T lymphocyte-related functions upon activation, therapeutics targeting cell quiescence to induce virus expression may not be appropriate for purging the Treg reservoir. CONCLUSIONS: Our results identify Tregs as a particular compartment within the latent reservoir that may require a specific approach for its purging

Molecular control of HIV-1 postintegration latency: implications for the development of new therapeutic strategies

The persistence of HIV-1 latent reservoirs represents a major barrier to virus eradication in infected patients under HAART since interruption of the treatment inevitably leads to a rebound of plasma viremia. Latency establishes early after infection notably (but not only) in resting memory CD4+ T cells and involves numerous host and viral trans-acting proteins, as well as processes such as transcriptional interference, RNA silencing, epigenetic modifications and chromatin organization. In order to eliminate latent reservoirs, new strategies are envisaged and consist of reactivating HIV-1 transcription in latently-infected cells, while maintaining HAART in order to prevent de novo infection. The difficulty lies in the fact that a single residual latently-infected cell can in theory rekindle the infection. Here, we review our current understanding of the molecular mechanisms involved in the establishment and maintenance of HIV-1 latency and in the transcriptional reactivation from latency. We highlight the potential of new therapeutic strategies based on this understanding of latency. Combinations of various compounds used simultaneously allow for the targeting of transcriptional repression at multiple levels and can facilitate the escape from latency and the clearance of viral reservoirs. We describe the current advantages and limitations of immune T-cell activators, inducers of the NF-κB signaling pathway, and inhibitors of deacetylases and histone- and DNA- methyltransferases, used alone or in combinations. While a solution will not be achieved by tomorrow, the battle against HIV-1 latent reservoirs is well- underway

Macrophage signaling in HIV-1 infection

The human immunodeficiency virus-1 (HIV-1) is a member of the lentivirus genus. The virus does not rely exclusively on the host cell machinery, but also on viral proteins that act as molecular switches during the viral life cycle which play significant functions in viral pathogenesis, notably by modulating cell signaling. The role of HIV-1 proteins (Nef, Tat, Vpr, and gp120) in modulating macrophage signaling has been recently unveiled. Accessory, regulatory, and structural HIV-1 proteins interact with signaling pathways in infected macrophages. In addition, exogenous Nef, Tat, Vpr, and gp120 proteins have been detected in the serum of HIV-1 infected patients. Possibly, these proteins are released by infected/apoptotic cells. Exogenous accessory regulatory HIV-1 proteins are able to enter macrophages and modulate cellular machineries including those that affect viral transcription. Furthermore HIV-1 proteins, e.g., gp120, may exert their effects by interacting with cell surface membrane receptors, especially chemokine co-receptors. By activating the signaling pathways such as NF-kappaB, MAP kinase (MAPK) and JAK/STAT, HIV-1 proteins promote viral replication by stimulating transcription from the long terminal repeat (LTR) in infected macrophages; they are also involved in macrophage-mediated bystander T cell apoptosis. The role of HIV-1 proteins in the modulation of macrophage signaling will be discussed in regard to the formation of viral reservoirs and macrophage-mediated T cell apoptosis during HIV-1 infection

The macrophage in HIV-1 infection: From activation to deactivation?

Macrophages play a crucial role in innate and adaptative immunity in response to microorganisms and are an important cellular target during HIV-1 infection. Recently, the heterogeneity of the macrophage population has been highlighted. Classically activated or type 1 macrophages (M1) induced in particular by IFN-γ display a pro-inflammatory profile. The alternatively activated or type 2 macrophages (M2) induced by Th-2 cytokines, such as IL-4 and IL-13 express anti-inflammatory and tissue repair properties. Finally IL-10 has been described as the prototypic cytokine involved in the deactivation of macrophages (dM). Since the capacity of macrophages to support productive HIV-1 infection is known to be modulated by cytokines, this review shows how modulation of macrophage activation by cytokines impacts the capacity to support productive HIV-1 infection. Based on the activation status of macrophages we propose a model starting with M1 classically activated macrophages with accelerated formation of viral reservoirs in a context of Th1 and proinflammatory cytokines. Then IL-4/IL-13 alternatively activated M2 macrophages will enter into the game that will stop the expansion of the HIV-1 reservoir. Finally IL-10 deactivation of macrophages will lead to immune failure observed at the very late stages of the HIV-1 disease

HIV/AIDS epidemiology, pathogenesis, prevention, and treatment.

The HIV-1 pandemic is a complex mix of diverse epidemics within and between countries and regions of the world, and is undoubtedly the defining public-health crisis of our time. Research has deepened our understanding of how the virus replicates, manipulates, and hides in an infected person. Although our understanding of pathogenesis and transmission dynamics has become more nuanced and prevention options have expanded, a cure or protective vaccine remains elusive. Antiretroviral treatment has transformed AIDS from an inevitably fatal condition to a chronic, manageable disease in some settings. This transformation has yet to be realised in those parts of the world that continue to bear a disproportionate burden of new HIV-1 infections and are most affected by increasing morbidity and mortality. This Seminar provides an update on epidemiology, pathogenesis, treatment, and prevention interventions pertinent to HIV-1

INTERACTIONS DU VIRUS DE L'IMMUNODEFICIENCE HUMAINE DE TYPE I AVEC LES MACROPHAGES EN CULTURE PRIMAIRE. RECHERCHE D'INHIBITEURS DE L'ENTREE VIRALE

LES MACROPHAGES CONSTITUENT UNE DES PREMIERES CIBLES DU VIH IN VIVO ET JOUENT UN ROLE IMPORTANT DANS L'INFECTION PAR CE VIRUS. ILS SE TROUVENT DANS L'ORGANISME DANS DIFFERENTS ETATS D'ACTIVATION ET DE DIFFERENCIATION ET CETTE HETEROGENEITE PEUT EXPLIQUER LES DONNEES CONTROVERSEES DE LA LITTERATURE SUR LES INTERACTIONS DU VIH AVEC CES CELLULES. NOUS AVONS UTILISE DES MACROPHAGES D'INDIVIDUS HOMOZYGOTES POUR LE GENE CCR5 COMPLET OU DELETE DE 32 PB. CECI A PERMIS DE MONTRER QUE CCR5 EST BIEN LE PRINCIPAL CORECEPTEUR UTILISE PAR LES SOUCHES VIRALES R5 POUR PENETRER DANS LES MACROPHAGES, ET QUE LA RESTRICTION D'INFECTION PAR LES SOUCHES X4 N'EST PAS DUE A UN DEFAUT D'EXPRESSION DE CXCR4. CEPENDANT, EN UTILISANT DEUX SYSTEMES DE DIFFERENCIATION DES MACROPHAGES, NOUS AVONS MONTRE QUE L'ACTIVITE ANTIVIRALE DE RANTES DEPEND DU SYSTEME UTILISE, QUI GENERE DES MACROPHAGES DANS DIFFERENTS ETATS D'ACTIVATION, AVEC NOTAMMENT UNE EXPRESSION DIFFERENTE DES PROTEOGLYCANES DE SURFACE. L'EXPRESSION DE CCR5 EST ALORS INCHANGEE ET CELLE DE CCR3 INDECELABLE. LES PROTEOGLYCANES DE SURFACE, NOTAMMENT LES CHONDROITINES SULFATES, EN FAVORISANT LA FIXATION DE RANTES, CONDITIONNENT SON ACTIVITE ANTIVIRALE, ALORS QUE LEURS HOMOLOGUES SOLUBLES NON SEULEMENT NE POTENTIALISENT PAS L'ACTIVITE ANTIVIRALE DE RANTES MAIS PEUVENT LA LEVER SOUS CERTAINES CONDITIONS. PAR AILLEURS, NOUS AVONS TENTE DE DEVELOPPER DES INHIBITEURS DE L'ENTREE VIRALE, NOTAMMENT DES DERIVES DE RANTES TRONQUES DE 7, 8, OU 9 RESIDUS DU COTE N-TERMINAL. CES DERIVES SE COMPORTENT COMME DES ANTAGONISTES DANS LE SENS OU ILS SONT DEPOURVUS D'ACTIVITE DE CHIMIOTAXIE ET INHIBENT EFFICACEMENT LES SOUCHES R5. CEPENDANT, BIEN QUE CES ANALOGUES SE FIXENT A CCR5 AVEC UNE AFFINITE SIMILAIRE A CELLE DE RANTES, LEUR ACTIVITE ANTIVIRALE EST DIX FOIS PLUS FAIBLE QUE RANTES, SANS DOUTE PARCE QUE CES DERIVES TRONQUES ONT PERDU LEUR PROPRIETE A DIMERISER. PAR TRANSFERT SUR UNE TOXINE DE SCORPION, NOUS AVONS EGALEMENT ANALYSE UNE MINIPROTEINE CHIMERIQUE REPRODUISANT LE SITE D'INTERACTION DE CD4 AVEC LA GP120. LA MINIPROTEINE, DONT LA STRUCTURE EST SUPERPOSABLE A CELLE DE CDR2, INHIBE A DES CONCENTRATIONS MICROMOLAIRES AUSSI BIEN LES ISOLATS R5 QUE X4 DE VIH-1. NOS DEUX APPROCHES INDIQUENT QU'UNE STRATEGIE VISANT A BLOQUER LE RECEPTEUR ET LES CORECEPTEURS DU VIRUS PEUT ETRE ENVISAGEE POUR LE DEVELOPPEMENT D'INHIBITEURS DE L'ENTREE VIRALE.PARIS-BIUSJ-Thèses (751052125) / SudocCentre Technique Livre Ens. Sup. (774682301) / SudocPARIS-BIUSJ-Physique recherche (751052113) / SudocSudocFranceF