Intrahost variations in the envelope receptor-binding domain (RBD) of HTLV-1 and STLV-1 primary isolates

Four primate (PTLV), human (HTLV) and simian (STLV) T-cell leukemia virus types, have been characterized thus far, with evidence of a simian zoonotic origin for HTLV-1, HTLV-2 and HTLV-3 in Africa. The PTLV envelope glycoprotein surface component (SUgp46) comprises a receptor-binding domain (RBD) that alternates hypervariable and highly conserved sequences. To further delineate highly conserved motifs in PTLV RBDs, we investigated the intrahost variability of HTLV-1 and STLV-1 by generating and sequencing libraries of DNA fragments amplified within the RBD of the SUgp46 env gene. Using new and highly cross-reactive env primer pairs, we observed the presence of Env quasispecies in HTLV-1 infected individuals and STLV-1 naturally infected macaques, irrespective of the clinical status. These intrahost variants helped us to define highly conserved residues and motifs in the RBD. The new highly sensitive env PCR described here appears suitable for the screening of all known variants of the different PTLV types and should, therefore, be useful for the analysis of seroindeterminate samples

No evidence for XMRV association in pediatric idiopathic diseases in France

Retroviruses have been linked to a variety of diseases such as neoplastic and immunodeficiency disorders and neurologic and respiratory diseases. Recently, a novel infectious human retrovirus, the xenotropic murine leukemia virus-related virus (XMRV), has been identified in cohorts of patients with either a familial type of prostate cancer or chronic fatigue syndrome. The apparent unrelatedness of these diseases raised the question of the potential involvement of XMRV in other diseases

Capture in the metabolic arena: co-selection of gamma and deltaretrovirus envelope glycoproteins and their receptors

International audiencen.

Imputabilité des rétrovirus dans les pathologies présumées post infectieuses de l'enfant

Introduction :Les rétrovirus infectieux des vertébrés sont regroupés en 7 genres : les Alpharétrovirus, les Bétarétrovirus, les Gammarétrovirus, les Deltarétrovirus, les Epsilonrétrovirus, les Lentivirus et les Spumavirus. Le Human T-cell Leukemia virus (HTLV), un deltarétrovirus, et l'Human Immunodeficiency Virus (HIV), un lentivirus, infectent l'homme. Des cas sporadiques d'infection par des spumavirus (virus Foamy) ont été décrits chez des personnes vivant en promiscuité avec des animaux infectés. Plusieurs éléments sont en faveur de l'existence de rétrovirus humains encore inconnus :-De nouvelles espèces de HTLV ont été découvertes récemment et de nombreux patients séroindéterminés compatibles avec la présence de nouvelles espèces de type HTLV ont été décrits. De plus la découverte d'un hypothétique nouveau rétrovirus le Xenotropic Murine Related retroVirus (XMRV) a recemment été discuté. De nombreuses pathologies humaines dites idiopathiques ont une symptomatologie très proche de maladies rétrovirales décrites chez les mammifères comme des maladies inflammatoires articulaires chroniques, des maladies inflammatoires des systèmes nerveux central et périphérique, des cytopénies, des syndromes myéloprolifératifs et des pathologies malignes. Une étiologie rétrovirale a, par exemple, été évoquée dans le syndrome de Kawasaki ou les anémies hémolytiques, mais sans avoir pu être formellement démontrée.-Le statut de super prédateur de l'homme rend la transmission inter-espèces possible.Toutes les recherches de nouveaux rétrovirus humains faites par le passé étaient basées sur des séquences communes à tous les rétrovirus, le gène de la polymérase ou la partie transmembranaire de la glycoprotéine d'enveloppe (Env). De ce fait, ces recherches ont été le plus souvent parasitées par les séquences endogènes rétrovirales ou des rétrovirus contaminants . Nous avons souhaité rechercher la présence de rétrovirus dans ces pathologies pédiatriques. Parallèlement, nous nous sommes intéressés aux (retro)virus pouvant se transmettre de la mère à l'enfant lors de l'allaitement. Méthode :Nous avons utilisé 2 méthodes pour rechercher des rétrovirus.1) PCR : Notre démarche cible paradoxalement la région la plus variable du génome des rétrovirus, Env, au niveau du RBD (pour Receptor-Binding Domain), domaine qui lie le récepteur d'entrée dans la cellule. Pour cela nous utilisons une méthode développée au laboratoire, basée sur des PCR dont les amorces sont constituées de courts motifs conservés, délimitant les domaines variables du RBD. Cette approche a déjà permis au laboratoire de mettre en évidence de nouveaux variants des PTLV (HTLV/STLV). Sur ce principe, nous avons ainsi conçu des amorces PCR pour la détection de RBD de deltarétrovirus bovin (Bovine Leukemia Virus) et infectant les primates (Prima T-Leukemia/Lymphoma Virus) ; de bêta rétrovirus infectant la souris (Mouse Mammary Tumor Virus) et des primates (Mason Pfizer Monkey Virus) et de gammaretrovirus infectant les félins/félidés (Feline Leukemia Virus), l'XMRV et un rétrovirus endogène porcin le PERV.2) mesure de l'activité reverse transcriptase de rétrovirus de type C au sein de liquides biologiques de patients malades. Résultats : Nous avons analysé en terme de patients 35 purpura thrombopénique immunologiques, 3 anémie hémolytique, 6 anémie arégénérative, 5 neutropénie, 1 aplasie médullaire idiopathique, 3 thrombocytose, 59 arthrite juvénile, 1 dermatomyosite, 9 purpura rhumatoïde, 4 syndrome de Kawasaki, 5 syndrome neurologique, 13 fièvre atypique, 3 leucose et 5 pathologies autres. Les recherches de rétrovirus par PCR et mesure d'activité reverse transcriptase se sont avérées négatives.Conclusion :Nous n'avons pas retrouvé de séquences rétrovirales au sein des échantillons analysés par ces deux techniques différentes. Cependant, ces résultats n'excluent pas l'hypothèse d'une étiologie rétrovirale.The infectious mammalian retrovirus constituting seven species: Alpharetroviruses, betaretroviruses, gammaretroviruses, deltaretrovirus, epsilonretroviruses, lentiviruses and, spumaviruses. Human T-cell Leukemia virus (HTLV), a deltaretrovirus, and Human Immunodeficiency Virus (HIV), a lentivirus, infect human. Sporadic cases of spumavirus (virus Foamy) infection have been described in persons living in promiscuity with infected animals. Recent Studies have shown the presence of an hypothetic gammaretrovirus, xenotropic murine leukemia related virus (XMRV), its existence is actually discussed.There are some facts pointing to the existence of human retrovirus not yet known. -New HTLV species have been recently described and a number of sero-indeterminate patients are compatible with the presence of new HTLV species.-Many idiopathic human diseases have clinical presentation close to retroviral mammalian diseases: chronic inflammatory articular diseases, central nervous system inflammatory diseases, cytopenia, myeloproliferative syndromes and malignant pathologies. For example a retroviral aetiology have been discussed in Kawasaki syndrome and autoimmune haemolytic anemia even though a complete proof haven't been found. The super human predatory status makes the interspecies transmission possible. All the research in new human retrovirus done in the past was based in common sequencies of retroviruses like polymerase gene or the transmenbranair part of glycoprotein envelope gene (Env). Thus most of these researches have been compromise by HERV sequences or retroviral contaminants.We research retroviruses in these diseases. We also have been interested by putative (retr)viral itransmission by breast milk.Methodology1)PDR: We design primer based on the most variable region of retroviruses, the RBD (Receptor-Binding Domain), which is the domain of Env that links the cellular receptor responsible of the cellular entry. For this we used a patented method developed in our laboratory based on PCR whose primers are composed of short conservative sequences delimiting variable areas of RBD.This approach has already allowed discovering new PTLV (HTLV/STLV) variants known. As a result, we have designed PCR primers for RBD for all the known deltaretrovirus, Bovine Leukaemia Virus, (BLV) and also for the detection of gammaretrovirus feline leukaemia virus (FeLV), XMRV and Porcine Endogenous Retrovirus (PERV).2)We measure the reverse transcriptase activity to detect Type C retrovirus in body fluid.Results:We analysed in terms of patients 35 Immunologic thrombopenic purpura, 3 hemolytic anemia, 6 aregenerative anemia, 5 neutropenia, 1 aplastic anemia, 3 thrombocytosis, 59 Idiopathic juvenile arthritis, 1 dermatomyositis, 9 Henoch-Scholein diseases, 4 Kawasaki syndrome, 5 neurological diseases, 13 atypic fevers, 3 leukosis and 5 others diseases. We do not found any virus by both methodologies.We do not find viruses by PCR and reverse transcrptase activity measurment however this fact does not exclude viral etiology, further analysis could be done.MONTPELLIER-BU Médecine UPM (341722108) / SudocSudocFranceF

Évolution et virulence des lentivirus de primates

Alors que la diffusion épidémique des virus de l’immunodéficience humaine (VIH) s’accompagne d’une mortalité très élevée, l’infection par les virus de l’immunodéficience simienne (SIV), retrouvée chez de nombreuses espèces de singes d’Afrique avec une forte prévalence, ne produit aucune maladie détectable. Les facteurs responsables de cette différence entre l’être humain et les porteurs naturels de SIV restent mal identifiés. Il est possible que cette différence ne réside ni dans les facteurs viraux, ni dans les facteurs d’hôte, mais dans la nature même de la relation hôte/virus, résultat d’un équilibre évolutif stable établi depuis longtemps dans certaines populations simiennes.While the AIDS epidemic caused by human immunodeficiency viruses (HIV) has resulted in the death of over 20 million people worldwide, simian immunodeficiency virus (SIV) infection, found in numerous African primate species, does not induce disease symptoms. The factors accounting for this difference between humans and natural host of SIV remain poorly understood. The entangled nature of the host/virus relationship could be the answer, rather than independent virus or host factors. Such a relationship is as a consequence of host/virus adaptation which has evolved over long periods in naturally infected primate species

Detection of Merkel cell polyomavirus on environmental surfaces

International audienceThe Merkel cell polyomavirus (MCPyV) is a human virus identifed recently which is associated with the Merkel cell carcinoma. This virus is also detected frequently in the skin of healthy individuals. The presence of MCPyV has been investigated on environmental surfaces in contact with human skin. Various surfaces in 4 laboratories, public places, and individual homes were swabbed. Human DNA and MCPyV DNA were detected in swabs by real-time PCR. MCPyV DNA levels were measured before an after DNase treatment in a set of 12 MCPyV DNA-positive samples. A total of 60 environmental surface samples were collected. Fifty-one (85.0%) were positive for human DNA detection and 45 (75.0%) were positive for MCPyV DNA detection. All samples positive for MCPyV DNA were positive for human DNA detection. After DNase treatment, a 1.3 log decrease in MCPyV DNA level was observed indicating that about 5% of viral DNA is protected from DNase degradation and might be associated with infectious virus. These results indicate that MCPyV DNA may be detected on environmental surfaces in contact with human skin. Detection of viral DNA might reflect the presence of infectious viral particles and transmission from environmental source to humans cannot be ruled out

Comparison of different extraction techniques to profile microRNAs from human sera and peripheral blood mononuclear cells

International audiencemicroRNAs (miRNAs) play crucial roles in major biological processes and their deregulations are often associated with human malignancies. As such, they represent appealing candidates as targets of innovative therapies. Another interesting aspect of their biology is that they are present in various biological fluids where, advantageously, they appear to be very stable. A plethora of studies have now reported their potential as biomarkers that can be used in diagnosis, prognosis and/or theranostic issues. However, the application of circulating miRNAs in clinical practices still requires the identification of highly efficient, robust and reproducible methods for their isolation from biological samples.In that context, we performed an independent cross-comparison of three commercially available RNA extraction kits for miRNAs isolation from human blood samples (Qiagen and Norgen kits as well as the new NucleoSpin miRNAs Plasma kit from Macherey-Nagel). miRNAs were further profiled using the Taqman Low Density Array technology