Francisco Veas | Institut de Recherche pour le Développement (IRD - France) (original) (raw)

Papers by Francisco Veas

International Journal of Infectious Diseases, 2021

Elsevier has created a COVID-19 resource centre with free information in English and Mandarin on ... more Elsevier has created a COVID-19 resource centre with free information in English and Mandarin on the novel coronavirus COVID-19. The COVID-19 resource centre is hosted on Elsevier Connect, the company's public news and information website. Elsevier hereby grants permission to make all its COVID-19-related research that is available on the COVID-19 resource centre-including this research content-immediately available in PubMed Central and other publicly funded repositories, such as the WHO COVID database with rights for unrestricted research re-use and analyses in any form or by any means with acknowledgement of the original source. These permissions are granted for free by Elsevier for as long as the COVID-19 resource centre remains active.

Place des différentes rubriques dans les déclarations des formations sanitaires non hospitalières... more Place des différentes rubriques dans les déclarations des formations sanitaires non hospitalières de Côte d'Ivoire en 1987 (Rubriques de la Classification mondiale des maladies de ['OMS

Methods in Molecular Biology

The 2016 Zika virus (ZIKV) outbreak in the Americas has been characterized by an increased associ... more The 2016 Zika virus (ZIKV) outbreak in the Americas has been characterized by an increased association frequency of fetal neuropathological abnormalities. To have a comprehensive and accurate knowledge of key elements of the clinically observed neurologic dysfunctions in Zika-infected babies, ZIKV transmission from mother to fetus needs to be deeply studied. Thus, it is important to determine the role of both virus-targeted cells and tissues within the mother-fetus interface. Cellular tropism and mechanisms of ZIKV transmission from mother to the fetus during early pregnancy still remain unknown on many aspects. To improve the characterization of the maternal-fetal ZIKV transmission, we have set up an ex vivo model using an organ culture approach with a light-invasive sampling from the first trimester of pregnancy samples. Thus, here we provide evidence that circulating epidemic ZIKV strains from Latin America widely target and destroy reproductive tissues, including the decidua basalis, fetal placenta, and umbilical cord. In addition, we show that ZIKV is able to differentially replicate in a large range of both maternal and fetal cells, including decidual fibroblasts and macrophages, fetal trophoblast and Hofbauer cells, as well as umbilical cord mesenchymal stem cells. This primary and broad ZIKV cellular tropism and the resulting abundant cytopathic-induced tissue effects during the first trimester of pregnancy show the upstream path of clinically observed congenital damages.

Dengue virus, an RNA virus of the Flaviviridae family, is characterized by its exceptional geneti... more Dengue virus, an RNA virus of the Flaviviridae family, is characterized by its exceptional genetic diversity, starting with its four viral serotypes, an intra-serotype genetic diversity illustrated by phenotypic variations (i.e. pathogenicity) and phylogeographic clusters. Cycles within its mosquito vector play an important role in this genetic diversity. After a limited passage of primary virus isolates, we investigated multiple sequences of dengue virus serotype 4 (DENV-4) isolates of naturally, acutely infected patients of the same geographic origin during the 2011 dengue fever outbreak in Thailand. Four patients were sampled as part of routine diagnosis and full virus sequences were generated after two passages in Vero cells and mosquito cell lines. These isolates consistently cluster with contemporaneous old-world DENV-4 clade (Asian), mainly composed of viruses isolated from Thailand after yearly epidemics from 2000-2011, which originated from the lineage first identified in 1...

L'invention concerne une methode de traitement de fievres hemorragiques virales telles que ce... more L'invention concerne une methode de traitement de fievres hemorragiques virales telles que celles provoquees par le virus de la dengue, qui comprend l'administration d'une composition renfermant une quantite pharmaceutiquement active d'un inhibiteur de metalloproteinase matricielle.

The invention concerns a family of peptides exhibiting high affinity and specificity for the gp12... more The invention concerns a family of peptides exhibiting high affinity and specificity for the gp120 viral protein, and methods for producing said peptides, and the use of said peptides. The inventive peptides are characterised in that they comprise the following sequence (A): TPA-P -Cys-P -Cys-P -Cys-Ala or Gln-Gly or (D) Asp or Ser or His or Asn-Xaa -Cys Thr or Ala-Cys-Xaa -NH2, wherein TPA represents thiopropionic acid; Xaa represents beta -naphthylalanine, phenylalanine or bi-phenylalanine; Xaa represents Gly, Val or Ileu; P represents 3 to 6 amino acids, P represents 2 to 4 amino acids and P represents 6 to 10 amino acids, the amino acids in P , P and P being natural or synthetic, identical or different and P , P and P having or not having a common sequence, said peptide having a beta hairpin conformation whereof the beta bend is formed by Ala or Glu-Gly or CDAsp or Ser or His or Asn-Xaa amino acid residues of its sequence (A). Said peptide can be used for making a medicine, a va...

Journal of Biological Chemistry

BMC Veterinary Research

Background Prior to the first recorded outbreak of Rift Valley fever (RVF) in Uganda, in March 20... more Background Prior to the first recorded outbreak of Rift Valley fever (RVF) in Uganda, in March 2016, earlier studies done until the 1970’s indicated the presence of the RVF virus (RVFV) in the country, without any recorded outbreaks in either man or animals. While severe outbreaks of RVF occurred in the neighboring countries, none were reported in Uganda despite forecasts that placed some parts of Uganda at similar risk. The Ministry of Agriculture, Animal Industry and Fisheries (MAAIF) undertook studies to determine the RVF sero-prevalence in risk prone areas. Three datasets from cattle sheep and goats were obtained; one from retrospective samples collected in 2010–2011 from the northern region; the second from the western region in 2013 while the third was from a cross-sectional survey done in 2016 in the south-western region. Laboratory analysis involved the use of the Enzyme Linked Immunosorbent Assays (ELISA). Data were subjected to descriptive statistical analyses, including n...

International Journal of Infectious Diseases, Apr 1, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Journal of Virology

To evaluate conserved structures of the surface gp120 subunit (SU) of the human immunodeficiency ... more To evaluate conserved structures of the surface gp120 subunit (SU) of the human immunodeficiency virus type 1 (HIV-1) envelope in gp120-cell interactions, we designed and produced an HIV-1 IIIB (HXB2R) gp120 carrying a deletion of amino acids E61 to S85. This sequence corresponds to a highly conserved predicted amphipathic alpha-helical structure located in the gp120 C1 region. The resultant soluble mutant with a deleted alpha helix 1 (gp120 ΔαHX1) exhibited a strong interaction with CXCR4, although CD4 binding was undetectable. The former interaction was specific since it inhibited the binding of the anti-CXCR4 monoclonal antibody (12G5), as well as SDF1α, the natural ligand of CXCR4. Additionally, the mutant gp120 was able to bind to CXCR4+/CD4− cells but not to CXCR4−/CD4− cells. Although efficiently expressed on cell surface, HIV envelope harboring the deleted gp120 ΔαHX1 associated with wild-type transmembrane gp41 was unable to induce cell-to-cell fusion with HeLa CD4+ cells. ...

Medical Hypotheses

Lyme disease is the most frequently reported zoonotic tick-borne disease worldwide, and the numbe... more Lyme disease is the most frequently reported zoonotic tick-borne disease worldwide, and the number of infected humans is increasing. Lyme disease (or Lyme borreliosis) is an affection caused by the spirochete Borrelia burgdorferi, sensu lato. Lyme disease is also reported as a variety of misleading clinical symptomatologies. Infected patient's blood serology is the most currently test used for its diagnosis. However, serology has a low sensitivity, which ranges from 34% to 70%. Thus, there are numerous subsequent false-negative diagnoses despite an active clinical infection profile. Therefore, alternative and more sensitive techniques are required to detect the antigens or nucleic acids of Borrelia. Actually, the most appropriate methodological approach seems to be the polymerase chain reaction (PCR). However, PCR will detect the only "visible" part available of the targeted DNA presence in the blood of the infected patients. Consequently PCR alone will not be conclusive enough to reach the final diagnosis. Considering the ability of Borrelia to invade host cells, we hypothesize that a selective lysis of all blood cells should improve the diagnostic sensitivity of the detection of Borrelia by PCR in whole blood, and subsequently reduce the false-negative diagnostic rate, thus improving the patient's diagnosis and therapeutic management.

Blood

The gp120 envelope glycoprotein of human immunodeficiency virus-1 (HIV-1) interacts with the CXCR... more The gp120 envelope glycoprotein of human immunodeficiency virus-1 (HIV-1) interacts with the CXCR4 chemokine receptor, but it is not known whether gp120 activates CXCR4-mediated signaling cascades in the same manner as its natural ligand, SDF1. We assessed the effects of wild-type gp120 and a mutant gp120 that interacts with CXCR4 but not CD4 on CD4−/CXCR4+ cells and CD4+/CXCR4+ cells, respectively. Under both experimental conditions, the interaction of CXCR4 and gp120 resulted in their CD4-independent cointernalization. Both molecules were translocated into early endosomes, whereas neither protein could be detected in late endosomes. Binding of gp120 to CXCR4 resulted in a CD4-independent phosphorylation of Pyk2 and an induction of chemotactic activity, demonstrating that this interaction has functional consequences. Interestingly, however, whereas SDF1 activated the ERK/MAP kinase pathway, this cascade was not induced by gp120. Together, these results suggest that the pathology ...

International Journal of Infectious Diseases

BACKGROUND Acute diarrhea is a leading cause of morbidity and mortality among children under five... more BACKGROUND Acute diarrhea is a leading cause of morbidity and mortality among children under five worldwide. As no published data is available on the occurrence of this infection in the Republic of Congo, this study aimed at 1! determining the prevalence and 2) characterizing genotypes of norovirus strains in Brazzaville. METHODS From June 2012 to June 2013, stool samples were collected from hospitalized young children with acute gastroenteritis. A total of 545 samples were tested for GI and GII norovirus infections using nested duplex reverse-transcription-polymerase chain reaction and sequencing.. RESULTS The GI and GII norovirus infection were detected in 148 samples. Males (28%) were not significantly more infected than females (25%). Norovirus infection was found exclusively in children aged under 24 months with a higher prevalence (P = 0,048) in the age group of 7-12 months and throughout the year with a peak in August and September). Genetic diversity of norovirus strains revealed that GII was the most prevalent (87%). No risk factor was significantly associated with norovirus infection. CONCLUSION This study showed that noroviruses are important agents responsible acute diarrhea in Congolese children and highlights the importance of continued surveillance.

The Journal of Infectious Diseases

Bioscience Reports

Gelatinolytic matrix metalloproteinases (MMP-2, -9) play a critical role not only in mammals phys... more Gelatinolytic matrix metalloproteinases (MMP-2, -9) play a critical role not only in mammals physiology but also during inflammation and healing processes. The natural stilbenoid, resveratrol (RES), exhibits potent antioxidant effects, in a hormetic mode of action, and is known to inhibit MMP-9. However, RES administration exhibits major issues, including poor bioavailability and water solubility, hampering its potential therapeutic effect in vivo. In the present study, we synthesized and evaluated five novel RES–lipid conjugates to increase their cell membrane penetration and improve their bioavailability. The best in vitro MMP-9 inhibitory activity of RES–lipids conjugates was observed with RES-linoleic acid (LA) (5 µM), when dissolved in a natural deep eutectic solvent (NADES), composed of an equimolar content of 1,2-propanediol:choline chloride (ChCl):water. The inhibition of MMP-9 expression by RES-LA in activated THP-1 monocytes, was, at least due to the deactivation of ERK1/2...

European Journal of Lipid Science and Technology

Despite the promising anti-oxidant and anti-inflammatory effects of resveratrol (RES) on human he... more Despite the promising anti-oxidant and anti-inflammatory effects of resveratrol (RES) on human health, pre-clinical and clinical studies are frequently disappointing, probably due to its low water-solubility and poor bioavailability. Even though a hormetic mode of action was clearly established for RES, the high doses commonly used to mitigate these issues, lead to adverse effects. Common hallmarks of multiple pathologies results from pathological-enhanced endothelial permeability due to both enhanced inflammation and matrix metalloprotease-9 (aMMP-9) activities. The main aim of this work was to optimize the RES capacity to inhibit aMMP-9 by using a new class of solvents, natural deep eutectic solvents (NADES) for a new RES formulation as compared with dimethyl-sulfoxide (DMSO). To obtain the appropriate NADES, 18 compounds combinations were prepared to select those exhibiting the optimized capacity to dissolve RES. The RES-NADES 1,2-propanediol:choline-chloride:water (PCW, 1:1:1 molar ratio) and compared with RES-DMSO for their aMMP-9-inhibitory capacities. Low concentrations of RES-NADES/PCW formulation exhibited both a biocompatible solubility and a strong increased aMMP-9-inhibitory activity, at least 10-fold, higher than RES-DMSO, reaching its hormetic mode of action. Following in vivo validations, some particular NADES could potentially be considered as the new generation of formulation for druggable compounds. Practical applications: Formulation of resveratrol in Natural Deep Eutectic solvents (NADES) optimizes its capacity to inhibit active matrix metalloprotease-9. The Resveratrol-NADES 1,2-propanediol:choline-was the most efficient and low concentrations exhibited both a biocompatible solubility and an increased aMMP-9-inhibitory activity, at least 10-fold, higher than RES-DMSO. Consequently, the NADES/PCW formulation allowed resveratrol to reach its hormetic mode of action. Following in vivo validations, some particular NADES could potentially be considered as the new generation of formulation for druggable compounds.

Infection Genetics and Evolution, 2008

Cellular and Molecular Biology, Feb 1, 1991

Our strategy of probes designing for major clones of Trypanosoma cruzi was performed taking into ... more Our strategy of probes designing for major clones of Trypanosoma cruzi was performed taking into account the: (i) clear identification of the major clones under multilocus study; (ii) hypothesis of a parallel evolution between the extranuclear and nuclear markers; (iii) structure of kDNA which allowed to amplify high variable regions of the minicircle (HVRm) by PCR. The large production of HVRm was very useful to test their ability to be used as probes for detection of DNA from a diversified genetic panel of T. cruzi. Our success in designing such probes has important implications on: the enhancement of 2 evolutive hypothesis about the clonal structure of T. cruzi and the parallel evolution of their extranuclear and nuclear genetics markers; direct diagnosis in patients and vectors. Studies on bio-clinical significance of major clones are discussed. This procedure could be used as a general strategy to generate DNA probes for Kinetoplastida.