Olivier Schwartz

..DC-SIGN facilitates capture and accumulation of viral particles in a vesicular compartment and inhibits viral fusion. Competition between CD4 and DC-SIGN for Env binding likely affects virus access to the cytosol and syncytium formation...

..The cell-type-dependent activity of DC-SIGN reflects the ability of HIV to replicate covertly in some cells, and not in others...

..We sought to overcome such a limitation by using a cell line releasing HIV-1 particles in an inducible way, and by exploiting the ability of a HIV-1 Nef mutant to be incorporated in virions at quite high levels...

..This Review highlights some of the most recent advances in our understanding of the biology of CHIKV and its interactions with the host...

..Tetherin, by imprinting virions in donor cells, is the first example of a surface restriction factor limiting viral cell-to-cell spread...

..Our results reveal a novel function for A3G, acting not only as an intrinsic antiviral factor but also as an inducer of the adaptive immune system...

..Altogether, our results indicate that DC-SIGN facilitates HTLV-1 infection and fusion of DCs through an ICAM-dependent mechanism...

..The protective efficacy of this vaccine should be studied in non-human primates. A combined measles-dengue vaccine might provide a one-shot approach to immunize children against both diseases where they co-exist...

..Altogether, our results highlight new aspects of DC-SIGN interactions with HIV-1. The lectin does not significantly protect captured virions against degradation and promotes MHC-I exogenous presentation of HIV-1 antigens...

..Altogether, these results indicate that cell-to-cell transfer is the predominant mode of HIV spread and help to explain why this virus replicates so efficiently in lymphoid organs...

..Therefore, Nef induces complex effects on the lymphocyte actin cytoskeleton and cellular morphology, which likely impacts the capacity of infected cells to circulate and to encounter and communicate with bystander cells...

..They help explain the incomplete protection by naturally secreted IFN during HIV infection and the unsatisfactory outcome of IFN treatment in HIV-infected patients...

..In HIV-infected individuals, these structures, by promoting concomitant infection of multiple targets in the vicinity of infected cells, may facilitate exponential viral growth and escape from immune responses...

..These results bring novel insights into the links that exist between T-cell activation and HIV spread, and suggest that HIV usurps components of the immunological synapse machinery to ensure its own spread through cell-to-cell contacts...

..CHIKV was highly sensitive to the antiviral activity of type I and II interferons. These results provide a general insight into the interaction between CHIKV and its mammalian host...

..This study defines an essential role for type I IFN, produced via cooperation between multiple host sensors and acting directly on nonhematopoietic cells, in the control of CHIKV...

..The present study provides the first data pertaining to the mode of HTLV-1 transport across a tight epithelial barrier, as can occur during mother-to-child HTLV-1 transmission during breastfeeding...

..Deciphering the immune responses to MVA in culture experiments will help in the design of innovative vaccine strategies...

..Alteration of endocytic and signaling networks at the immunological synapse likely impacts the function and fate of HIV-1-infected cells...

..These results provide new insights into how HIV-1 spreads from DCs to T lymphocytes and manipulates immune responses. They help explain how Nef may act as a virulence factor in vivo...

..Characterization of the mechanisms of innate recognition of HIV-infected cells allows a better understanding of the pathogenic and exacerbated immunologic events associated with HIV infection...

..These results highlight the interplay between nonimmune and immune cells during Chikungunya virus infection and suggest an important role for nonhematopoietic cells as a critical source of IFN-α/β...

..The increased efficiency of this infection route may thus be attributed to the high local concentrations of virus particles at sites of cellular contacts rather than to a qualitatively different transmission process...

..These data reveal a novel negative feedback loop involving HPK-1-dependent serine phosphorylation of SLP-76 and 14-3-3 protein recruitment, which tunes T cell activation...

..In infected hosts, the persistence strategy employed by FV might be based on low levels of replication, as well as avoidance of cells expressing large amounts of active cytidine deaminases...

..Our results unravel the mechanisms of MHC-II-restricted HIV antigen presentation by DCs and describe how HIV gains access to the very cells designed by the immune system to counteract this pathogen...

..Altogether, these results suggest that Siva-1 might participate in the CD4-initiated signaling apoptotic pathway induced by the HIV-1 envelope in T-lymphoid cells...

..Our results strongly suggest that HIV-1 escapes CTL surveillance by introducing mutations leading to HIV ARF-epitope destruction by proteasomes...

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..Our study suggests that inducers of autophagy may limit the pathogenesis of acute Chikungunya disease...

..Therefore, FV are potent inducers of type I IFN by pDCs and by PBMCs. This previously underestimated activation of the innate immune response may be involved in the control of viral replication in humans...

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..Altogether, these results strongly suggest that rafts are not a key element involved in the effects of Nef on trafficking of cellular proteins and on viral replication...

..NKp44LCD4 T cells are highly sensitive to the NK lysis activity. In contrast, HIV-infected CD4 T cells are resistant to NK killing, suggesting that HIV-1 developed strategies to avoid detection by the host cell immunity...

..This should be taken into account when designing vaccine strategies aimed at activating these responses...

..In this Progress article, we describe how SAMHD1 regulates the pool of intracellular nucleotides to control HIV replication and the innate immune response...

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..This candidate vaccine will be next tested in non-human primates. As a pediatric vaccine, it might protect children and adolescents simultaneously from measles and HIV...

..Our results identify SCS macrophages as primary mediators of NK cell activation in response to lymph-borne viral particles suggesting that they act as early sensors of local infection or delivery of viral-based vaccines...

..High affinity interaction of viral glycoproteins with oligomeric lectins might represent a strategy by which HCV targets to and concentrates in the liver and infects dendritic cells...

..Altogether, our results indicate that fever may directly stimulate HIV-1 replication, in a process involving Hsp90 and facilitation of Tat-mediated LTR activity...

..Thus, although HTLV-1 DNA can indeed be edited by at least four APOBEC3 cytidine deaminases in vitro, they are conspicuously absent in vivo...

..This review will recapitulate current knowledge with a particular emphasis on the questions live microscopy has raised...

..7% of cases. Since the cellular targets of CHIK virus in humans are unknown, we studied the pathogenic events and targets of CHIK infection in skeletal muscle...

..The experiments suggest that LOS variation may have evolved as a mechanism for GC to avoid phagocytosis by DCs...

..Thus, as for human immunodeficiency virus (HIV), which is captured by the same receptor, DC-SIGN-mediated entry of M. tuberculosis in DCs in vivo is likely to influence bacterial persistence and host immunity...

..Thus, HIV-1 has developed a strategy for survival within infected macrophages involving prevention of acidification within a devoted endocytic virus assembly compartment...

..Mosquito-cell-derived DVs may have differential infectivity for DC-SIGN-expressing cells. We suggest that the differential use of DC-SIGN by viral envelope glycoproteins may account for the immunopathogenesis of DVs...

..The results emphasize that multiple activities govern Nef's effects on HIV replication and argue against a role of virion incorporation for Nef's activity as pathogenicity factor...

..Activation of LARG in DCs exposed to HIV was required for the formation of virus-T cell synapses. Thus, HIV sequestration by and stimulation of DC-SIGN helps HIV evade immune responses and spread to cells...

..tuberculosis binding to DC-SIGN is more complicated than previously thought and provides further insight into the mechanisms of M. tuberculosis recognition by the immune system...

..pestis and human DCs can be reduced by a combination treatment with anti-CD209 and anti-CD207 antibodies. This study shows that human DC-SIGN is a receptor for Y. pestis that promotes phagocytosis by DCs in vitro...

..coli in part by interacting with the complete core region of the LPS molecule. These results provide a mechanism for how O antigen acts as an antiphagocytic factor...

..This dual, two-step effect likely participates in the efficient defense of the cell genome against invading endogenous retroelements...

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..i., suggesting the ocurrence of multiprotein complexes involving these three proteins at early steps of the HIV-1 virus life cycle. Such IEM patterns were not observed with a noninfectious, envelope deletion mutant of HIV-1...

..Altogether, these data demonstrate that Nef interferes with the differentiation of a primitive lymphoid human precursor with a T/NK potential...

..We propose that modulating lymphocyte signalling, apoptosis and intracellular trafficking ensures efficient spread of the virus in the hostile environment of the immune system...