Cellules myéloïdes et Immunité

Publications de l’équipe

Année de publication : 2019

Emiliano Roselli, Paula Araya, Nicolás Gonzalo Núñez, Gerardo Gatti, Francesca Graziano, Christine Sedlik, Philippe Benaroch, Eliane Piaggio, Mariana Maccioni (2019 Apr 6)

TLR3 Activation of Intratumoral CD103 Dendritic Cells Modifies the Tumor Infiltrate Conferring Anti-tumor Immunity.

Frontiers in immunology : 503 : DOI : 10.3389/fimmu.2019.00503 En savoir plus
Résumé

An important challenge in cancer immunotherapy is to expand the number of patients that benefit from immune checkpoint inhibitors (CI), a fact that has been related to the pre-existence of an efficient anti-tumor immune response. Different strategies are being proposed to promote tumor immunity and to be used in combined therapies with CI. Recently, we reported that intratumoral administration of naked poly A:U, a dsRNA mimetic empirically used in early clinical trials with some success, delays tumor growth and prolongs mice survival in several murine cancer models. Here, we show that CD103 cDC1 and, to a much lesser extent CD11b cDC2, are the only populations expressing TLR3 at the tumor site, and consequently could be potential targets of poly A:U. Upon poly A:U administration these cells become activated and elicit profound changes in the composition of the tumor immune infiltrate, switching the immune suppressive tumor environment to anti-tumor immunity. The sole administration of naked poly A:U promotes striking changes within the lymphoid compartment, with all the anti-tumoral parameters being enhanced: a higher frequency of CD8 Granzyme B T cells, (lower Treg/CD8 ratio) and an important expansion of tumor-antigen specific CD8 T cells. Also, PD1/PDL1 showed an increased expression indicating that neutralization of this axis could be exploited in combination with poly A:U. Our results shed new light to promote further assays in this dsRNA mimetic to the clinical field.

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Vasco Rodrigues, Philippe Benaroch (2019 Mar 23)

Macrophages hide HIV in the urethra.

Nature microbiology : 556-557 : DOI : 10.1038/s41564-019-0418-5 En savoir plus
Résumé

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Année de publication : 2018

Anna Baranska, Alaa Shawket, Mabel Jouve, Myriam Baratin, Camille Malosse, Odessa Voluzan, Thien-Phong Vu Manh, Frédéric Fiore, Marc Bajénoff, Philippe Benaroch, Marc Dalod, Marie Malissen, Sandrine Henri, Bernard Malissen (2018 Mar 8)

Unveiling skin macrophage dynamics explains both tattoo persistence and strenuous removal.

The Journal of experimental medicine : 1115-1133 : DOI : 10.1084/jem.20171608 En savoir plus
Résumé

Here we describe a new mouse model that exploits the pattern of expression of the high-affinity IgG receptor (CD64) and allows diphtheria toxin (DT)-mediated ablation of tissue-resident macrophages and monocyte-derived cells. We found that the myeloid cells of the ear skin dermis are dominated by DT-sensitive, melanin-laden cells that have been missed in previous studies and correspond to macrophages that have ingested melanosomes from neighboring melanocytes. Those cells have been referred to as melanophages in humans. We also identified melanophages in melanocytic melanoma. Benefiting of our knowledge on melanophage dynamics, we determined the identity, origin, and dynamics of the skin myeloid cells that capture and retain tattoo pigment particles. We showed that they are exclusively made of dermal macrophages. Using the possibility to delete them, we further demonstrated that tattoo pigment particles can undergo successive cycles of capture-release-recapture without any tattoo vanishing. Therefore, congruent with dermal macrophage dynamics, long-term tattoo persistence likely relies on macrophage renewal rather than on macrophage longevity.

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Année de publication : 2017

Vasco Rodrigues, Nicolas Ruffin, Mabel San-Roman, Philippe Benaroch (2017 Dec 19)

Myeloid Cell Interaction with HIV: A Complex Relationship.

Frontiers in immunology : 1698 : DOI : 10.3389/fimmu.2017.01698 En savoir plus
Résumé

Cells of the myeloid lineage, particularly macrophages, serve as primary hosts for HIV , along with CD4 T lymphocytes. Macrophages are present in virtually every tissue of the organism, including locations with negligible T cell colonization, such as the brain, where HIV-mediated inflammation may lead to pathological sequelae. Moreover, infected macrophages are present in multiple other tissues. Recent evidence obtained in humanized mice and macaque models highlighted the capacity of macrophages to sustain HIV replication in the absence of T cells. Combined with the known resistance of the macrophage to the cytopathic effects of HIV infection, such data bring a renewed interest in this cell type both as a vehicle for viral spread as well as a viral reservoir. While our understanding of key processes of HIV infection of macrophages is far from complete, recent years have nevertheless brought important insight into the uniqueness of the macrophage infection. Productive infection of macrophages by HIV can occur by different routes including from phagocytosis of infected T cells. In macrophages, HIV assembles and buds into a peculiar plasma membrane-connected compartment that preexists to the infection. While the function of such compartment remains elusive, it supposedly allows for the persistence of infectious viral particles over extended periods of time and may play a role on viral transmission. As cells of the innate immune system, macrophages have the capacity to detect and respond to viral components. Recent data suggest that such sensing may occur at multiple steps of the viral cycle and impact subsequent viral spread. We aim to provide an overview of the HIV-macrophage interaction along the multiple stages of the viral life cycle, extending when pertinent such observations to additional myeloid cell types such as dendritic cells or blood monocytes.

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Jérémie Decalf, Marion Desdouits, Vasco Rodrigues, François-Xavier Gobert, Matteo Gentili, Santy Marques-Ladeira, Célia Chamontin, Marylène Mougel, Bruna Cunha de Alencar, Philippe Benaroch (2017 May 12)

Sensing of HIV-1 Entry Triggers a Type I Interferon Response in Human Primary Macrophages.

Journal of virology : DOI : e00147-17 En savoir plus
Résumé

Along with CD4(+) T lymphocytes, macrophages are a major cellular source of HIV-1 replication and a potential viral reservoir. Following entry and reverse transcription in macrophages, cloaking of the viral cDNA by the HIV-1 capsid limits its cytosolic detection, enabling efficient replication. However, whether incoming HIV-1 particles are sensed by macrophages prior to reverse transcription remains unclear. Here, we show that HIV-1 triggers a broad expression of interferon (IFN)-stimulated genes (ISG) in monocyte-derived macrophages within a few hours after infection. This response does not require viral reverse transcription or the presence of HIV-1 RNA within particles, but viral fusion is essential. This response is elicited by viruses carrying different envelope proteins and thus different receptors to proceed for viral entry. Expression of ISG in response to viral entry requires TBK1 activity and type I IFNs signaling. Remarkably, the ISG response is transient but affects subsequent viral spread. Together, our results shed light on an early step of HIV-1 sensing by macrophages at the level of entry, which confers an early protection through type I IFN signaling and has potential implications in controlling the infection.IMPORTANCE HIV infection is restricted to T lymphocytes and macrophages. HIV-1-infected macrophages are found in many tissues of infected patients, even under antiretroviral therapy, and are considered a viral reservoir. How HIV-1 is detected and what type of responses are elicited upon sensing remain in great part elusive. The kinetics and localization of the production of cytokines such as interferons in response to HIV is of critical importance to understanding how the infection and the immune response are established. Our study provides evidence that macrophages can detect HIV-1 as soon as it enters the cell. Interestingly, this sensing is independent of the presence of viral nucleic acids within the particles but requires their fusion with the macrophages. This triggers a low interferon response, which activates an antiviral program protecting cells against further viral challenge and thus potentially limiting the spread of the infection.

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Peter See, Charles-Antoine Dutertre, Jinmiao Chen, Patrick Günther, Naomi McGovern, Sergio Erdal Irac, Merry Gunawan, Marc Beyer, Kristian Händler, Kaibo Duan, Hermi Rizal Bin Sumatoh, Nicolas Ruffin, Mabel Jouve, Ester Gea-Mallorquí, Raoul C M Hennekam, Tony Lim, Chan Chung Yip, Ming Wen, Benoit Malleret, Ivy Low, Nurhidaya Binte Shadan, Charlene Foong Shu Fen, Alicia Tay, Josephine Lum, Francesca Zolezzi, Anis Larbi, Michael Poidinger, Jerry K Y Chan, Qingfeng Chen, Laurent Rénia, Muzlifah Haniffa, Philippe Benaroch, Andreas Schlitzer, Joachim L Schultze, Evan W Newell, Florent Ginhoux (2017 May 6)

Mapping the human DC lineage through the integration of high-dimensional techniques.

Science (New York, N.Y.) : DOI : eaag3009 En savoir plus
Résumé

Dendritic cells (DC) are professional antigen-presenting cells that orchestrate immune responses. The human DC population comprises two main functionally specialized lineages, whose origins and differentiation pathways remain incompletely defined. Here, we combine two high-dimensional technologies-single-cell messenger RNA sequencing (scmRNAseq) and cytometry by time-of-flight (CyTOF)-to identify human blood CD123(+)CD33(+)CD45RA(+) DC precursors (pre-DC). Pre-DC share surface markers with plasmacytoid DC (pDC) but have distinct functional properties that were previously attributed to pDC. Tracing the differentiation of DC from the bone marrow to the peripheral blood revealed that the pre-DC compartment contains distinct lineage-committed subpopulations, including one early uncommitted CD123(high) pre-DC subset and two CD45RA(+)CD123(low) lineage-committed subsets exhibiting functional differences. The discovery of multiple committed pre-DC populations opens promising new avenues for the therapeutic exploitation of DC subset-specific targeting.

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Année de publication : 2016

Aditi Varthaman, Hélène D Moreau, Mathieu Maurin, Philippe Benaroch (2016 Dec 3)

TLR3-Induced Maturation of Murine Dendritic Cells Regulates CTL Responses by Modulating PD-L1 Trafficking.

PloS one : e0167057 : DOI : 10.1371/journal.pone.0167057 En savoir plus
Résumé

Targeting TLR3 through formulations of polyI:C is widely studied as an adjuvant in cancer immunotherapy. The efficacy of such targeting has been shown to increase in combination with anti-PD-L1 treatment. Nevertheless, the mechanistic details of the effect of polyI:C on DC maturation and the impact on T-DC interactions upon PD-L1 blockade is largely unknown. Here we found that although DC treatment with polyI:C induced a potent inflammatory response including the production of type I interferon, polyI:C treatment of DCs impaired activation of peptide specific CD8+ T cells mainly due to PD-L1. Interestingly, we found that PD-L1 trafficking to the cell surface is regulated in two waves in polyI:C-treated DCs. One induced upon overnight treatment and a second more rapid one, specific to polyI:C treatment, was induced upon CD40 signaling leading to a further increase in surface PD-L1 in DCs. The polyI:C-induced cell surface PD-L1 reduced the times of contact between DCs and T cells, potentially accounting for limited T cell activation. Our results reveal a novel CD40-dependent regulation of PD-L1 trafficking induced upon TLR3 signaling that dictates its inhibitory activity. These results provide a mechanistic framework to understand the efficacy of anti-PD-L1 cancer immunotherapy combined with TLR agonists.

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Année de publication : 2015

Francesca Graziano, Marion Desdouits, Livia Garzetti, Paola Podini, Massimo Alfano, Anna Rubartelli, Roberto Furlan, Philippe Benaroch, Guido Poli (2015 Jun 10)

Extracellular ATP induces the rapid release of HIV-1 from virus containing compartments of human macrophages.

Proceedings of the National Academy of Sciences of the United States of America : E3265-73 : DOI : 10.1073/pnas.1500656112 En savoir plus
Résumé

HIV type 1 (HIV-1) infects CD4(+) T lymphocytes and tissue macrophages. Infected macrophages differ from T cells in terms of decreased to absent cytopathicity and for active accumulation of new progeny HIV-1 virions in virus-containing compartments (VCC). For these reasons, infected macrophages are believed to act as « Trojan horses » carrying infectious particles to be released on cell necrosis or functional stimulation. Here we explored the hypothesis that extracellular ATP (eATP) could represent a microenvironmental signal potentially affecting virion release from VCC of infected macrophages. Indeed, eATP triggered the rapid release of infectious HIV-1 from primary human monocyte-derived macrophages (MDM) acutely infected with the CCR5-dependent HIV-1 strain. A similar phenomenon was observed in chronically infected promonocytic U1 cells differentiated to macrophage-like cells (D-U1) by costimulation with phorbol esters and urokinase-type plasminogen activator. Worthy of note, eATP did not cause necrotic, apoptotic, or pyroptotic cell death, and its effect on HIV-1 release was suppressed by Imipramine (an antidepressant agent known to inhibit microvesicle formation by interfering with membrane-associated acid sphingomyelinase). Virion release was not triggered by oxidized ATP, whereas the effect of eATP was inhibited by a specific inhibitor of the P2X7 receptor (P2X7R). Thus, eATP triggered the discharge of virions actively accumulating in VCC of infected macrophages via interaction with the P2X7R in the absence of significant cytopathicity. These findings suggest that the microvesicle pathway and P2X7R could represent exploitable targets for interfering with the VCC-associated reservoir of infectious HIV-1 virions in tissue macrophages.

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Pehuén Pereyra Gerber, Mercedes Cabrini, Carolina Jancic, Luciana Paoletti, Claudia Banchio, Catalina von Bilderling, Lorena Sigaut, Lía I Pietrasanta, Gabriel Duette, Eric O Freed, Genevieve de Saint Basile, Catarina Ferreira Moita, Luis Ferreira Moita, Sebastian Amigorena, Philippe Benaroch, Jorge Geffner, Matías Ostrowski (2015 May 6)

Rab27a controls HIV-1 assembly by regulating plasma membrane levels of phosphatidylinositol 4,5-bisphosphate.

The Journal of cell biology : 435-52 : DOI : 10.1083/jcb.201409082 En savoir plus
Résumé

During the late stages of the HIV-1 replication cycle, the viral polyprotein Pr55(Gag) is recruited to the plasma membrane (PM), where it binds phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) and directs HIV-1 assembly. We show that Rab27a controls the trafficking of late endosomes carrying phosphatidylinositol 4-kinase type 2 α (PI4KIIα) toward the PM of CD4(+) T cells. Hence, Rab27a promotes high levels of PM phosphatidylinositol 4-phosphate and the localized production of PI(4,5)P2, therefore controlling Pr55(Gag) membrane association. Rab27a also controls PI(4,5)P2 levels at the virus-containing compartments of macrophages. By screening Rab27a effectors, we identified that Slp2a, Slp3, and Slac2b are required for the association of Pr55(Gag) with the PM and that Slp2a cooperates with Rab27a in the recruitment of PI4KIIα to the PM. We conclude that by directing the trafficking of PI4KIIα-positive endosomes toward the PM, Rab27a controls PI(4,5)P2 production and, consequently, HIV-1 replication.

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Année de publication : 2014

Herwig Koppensteiner, Kristin Höhne, Marcos Vinicius Gondim, Francois-Xavier Gobert, Miriam Widder, Swantje Gundlach, Anke Heigele, Frank Kirchhoff, Michael Winkler, Philippe Benaroch, Michael Schindler (2014 Jan 4)

Lentiviral Nef suppresses iron uptake in a strain specific manner through inhibition of Transferrin endocytosis.

Retrovirology : 1 : DOI : 10.1186/1742-4690-11-1 En savoir plus
Résumé

Increased cellular iron levels are associated with high mortality in HIV-1 infection. Moreover iron is an important cofactor for viral replication, raising the question whether highly divergent lentiviruses actively modulate iron homeostasis. Here, we evaluated the effect on cellular iron uptake upon expression of the accessory protein Nef from different lentiviral strains.

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Année de publication : 2013

Stefano Berre, Raphaël Gaudin, Bruna Cunha de Alencar, Marion Desdouits, Mélanie Chabaud, Nadia Naffakh, Marc Rabaza-Gairi, François-Xavier Gobert, Mabel Jouve, Philippe Benaroch (2013 Oct 21)

CD36-specific antibodies block release of HIV-1 from infected primary macrophages and its transmission to T cells.

The Journal of experimental medicine : 2523-38 : DOI : 10.1084/jem.20130566 En savoir plus
Résumé

HIV-1-infected macrophages likely represent viral reservoirs, as they accumulate newly formed virions in internal virus-containing compartments (VCCs). However, the nature and biogenesis of VCCs remain poorly defined. We show that upon HIV-1 infection of primary human macrophages, Gag is recruited to preexisting compartments containing the scavenger receptor CD36, which then become VCCs. Silencing of CD36 in HIV-1-infected macrophages decreases the amount of virions released. Strikingly, soluble anti-CD36 antibodies, but not the natural ligands of CD36, inhibit release of virions from HIV-1-infected macrophages and the transmission of virus to CD4(+) T cells. The effect of the antibodies is potent, rapid, and induces the retention of virions within VCCs. Ectopic expression of CD36 in HeLa cells renders them susceptible to the inhibitory effect of the anti-CD36 mAb upon HIV-1 infection. We show that the anti-CD36 mAb inhibits HIV-1 release by clustering newly formed virions at their site of budding, and that signaling via CD36 is not required. Thus, HIV-1 reservoirs in macrophages may be tackled therapeutically using anti-CD36 antibodies to prevent viral dissemination.

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Marina Colombo, Catarina Moita, Guillaume van Niel, Joanna Kowal, James Vigneron, Philippe Benaroch, Nicolas Manel, Luis F Moita, Clotilde Théry, Graça Raposo (2013 Oct 8)

Analysis of ESCRT functions in exosome biogenesis, composition and secretion highlights the heterogeneity of extracellular vesicles.

Journal of cell science : 5553-65 : DOI : 10.1242/jcs.128868 En savoir plus
Résumé

Exosomes are extracellular vesicles (EVs) secreted upon fusion of endosomal multivesicular bodies (MVBs) with the plasma membrane. The mechanisms involved in their biogenesis have not yet been fully identified although they could be used to modulate exosome formation and therefore are a promising tool in understanding exosome functions. We have performed an RNA interference screen targeting 23 components of the endosomal sorting complex required for transport (ESCRT) machinery and associated proteins in MHC class II (MHC II)-expressing HeLa-CIITA cells. Silencing of HRS, STAM1 or TSG101 reduced the secretion of EV-associated CD63 and MHC II but each gene altered differently the size and/or protein composition of secreted EVs, as quantified by immuno-electron microscopy. By contrast, depletion of VPS4B augmented this secretion while not altering the features of EVs. For several other ESCRT subunits, it was not possible to draw any conclusions about their involvement in exosome biogenesis from the screen. Interestingly, silencing of ALIX increased MHC II exosomal secretion, as a result of an overall increase in intracellular MHC II protein and mRNA levels. In human dendritic cells (DCs), ALIX depletion also increased MHC II in the cells, but not in the released CD63-positive EVs. Such differences could be attributed to a greater heterogeneity in size, and higher MHC II and lower CD63 levels in vesicles recovered from DCs as compared with HeLa-CIITA. The results reveal a role for selected ESCRT components and accessory proteins in exosome secretion and composition by HeLa-CIITA. They also highlight biogenetic differences in vesicles secreted by a tumour cell line and primary DCs.

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Raphaël Gaudin, Bruna Cunha de Alencar, Nathalie Arhel, Philippe Benaroch (2013 Apr 8)

HIV trafficking in host cells: motors wanted!

Trends in cell biology : 652-62 : DOI : 10.1016/j.tcb.2013.09.004 En savoir plus
Résumé

Throughout the viral replication cycle, viral proteins, complexes, and particles need to be transported within host cells. These transport events are dependent on the host cell cytoskeleton and molecular motors. However, the mechanisms by which virus is trafficked along cytoskeleton filaments and how molecular motors are recruited and regulated to guarantee successful integration of the viral genome and production of new viruses has only recently begun to be understood. Recent studies on HIV have identified specific molecular motors involved in the trafficking of these viral particles. Here we review recent literature on the transport of HIV components in the cell, provide evidence for the identity and role of molecular motors in this process, and highlight how these trafficking events may be related to those occurring with other viruses.

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Année de publication : 2012

Raphaël Gaudin, Bruna Cunha de Alencar, Mabel Jouve, Stefano Bèrre, Emmanuel Le Bouder, Michael Schindler, Aditi Varthaman, François-Xavier Gobert, Philippe Benaroch (2012 Oct 22)

Critical role for the kinesin KIF3A in the HIV life cycle in primary human macrophages.

The Journal of cell biology : 467-79 : DOI : 10.1083/jcb.201201144 En savoir plus
Résumé

Macrophages are long-lived target cells for HIV infection and are considered viral reservoirs. HIV assembly in macrophages occurs in virus-containing compartments (VCCs) in which virions accumulate and are stored. The regulation of the trafficking and release of these VCCs remains unknown. Using high resolution light and electron microscopy of HIV-1-infected primary human macrophages, we show that the spatial distribution of VCCs depended on the microtubule network and that VCC-limiting membrane was closely associated with KIF3A+ microtubules. Silencing KIF3A strongly decreased virus release from HIV-1-infected macrophages, leading to VCC accumulation intracellularly. Time-lapse microscopy further suggested that VCCs and associated KIF3A move together along microtubules. Importantly, KIF3A does not play a role in HIV release from T cells that do not possess VCCs. These results reveal that HIV-1 requires the molecular motor KIF3 to complete its cycle in primary macrophages. Targeting this step may lead to novel strategies to eliminate this viral reservoir.

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Alejandra Garcia-Cattaneo, François-Xavier Gobert, Mélanie Müller, Florent Toscano, Marcella Flores, Aurianne Lescure, Elaine Del Nery, Philippe Benaroch (2012 May 18)

Cleavage of Toll-like receptor 3 by cathepsins B and H is essential for signaling.

Proceedings of the National Academy of Sciences of the United States of America : 9053-8 : DOI : 10.1073/pnas.1115091109 En savoir plus
Résumé

Toll-like receptor (TLR) 3 is an endosomal TLR that mediates immune responses against viral infections upon activation by its ligand double-stranded RNA, a replication intermediate of most viruses. TLR3 is expressed widely in the body and activates both the innate and adaptive immune systems. However, little is known about how TLR3 intracellular trafficking and maturation are regulated. Here we show that newly synthesized endogenous TLR3 is transported through the ER and Golgi apparatus to endosomes, where it is rapidly cleaved. TLR3 protein expression is up-regulated by its own ligand, leading to the accumulation of its cleaved form. In agreement with its proposed role as a transporter, UNC93B1 expression is required for TLR3 cleavage and signaling. Furthermore, TLR3 signaling and cleavage are sensitive to cathepsin inhibition. Cleavage occurs between aa 252 and 346, and results in a functional receptor that signals upon activation. A truncated form of TLR3 lacking the N-terminal 345 aa also signals from acidic compartments in response to ligand activation. Screening of the human cathepsin family by RNA interference identified cathepsins B and H as key mediators of TLR3 processing. Taken together, our data indicate that TLR3 proteolytic processing is essential for its function, and suggest a mechanism of tight control of TLR3 signaling and thus immunity.

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