Publications by authors named "Sandrine A Lacour"

13 Publications

  • Page 1 of 1

Exploration of binary protein-protein interactions between tick-borne flaviviruses and Ixodes ricinus.

Parasit Vectors 2021 Mar 6;14(1):144. Epub 2021 Mar 6.

UMR 1161 Virologie Laboratoire de Santé Animale, ANSES, INRAE, Ecole Nationale Vétérinaire d'Alfort, Paris-Est Sup, Maisons-Alfort, France.

Background: Louping ill virus (LIV) and tick-borne encephalitis virus (TBEV) are tick-borne flaviviruses that are both transmitted by the major European tick, Ixodes ricinus. Despite the importance of I. ricinus as an arthropod vector, its capacity to acquire and subsequently transmit viruses, known as vector competence, is poorly understood. At the molecular scale, vector competence is governed in part by binary interactions established between viral and cellular proteins within infected tick cells.

Methods: To investigate virus-vector protein-protein interactions (PPIs), the entire set of open reading frames for LIV and TBEV was screened against an I. ricinus cDNA library established from three embryonic tick cell lines using yeast two-hybrid methodology (Y2H). PPIs revealed for each viral bait were retested in yeast by applying a gap repair (GR) strategy, and notably against the cognate protein of both viruses, to determine whether the PPIs were specific for a single virus or common to both. The interacting tick proteins were identified by automatic BLASTX, and in silico analyses were performed to expose the biological processes targeted by LIV and TBEV.

Results: For each virus, we identified 24 different PPIs involving six viral proteins and 22 unique tick proteins, with all PPIs being common to both viruses. According to our data, several viral proteins (pM, M, NS2A, NS4A, 2K and NS5) target multiple tick protein modules implicated in critical biological pathways. Of note, the NS5 and pM viral proteins establish PPI with several tumor necrosis factor (TNF) receptor-associated factor (TRAF) proteins, which are essential adaptor proteins at the nexus of multiple signal transduction pathways.

Conclusion: We provide the first description of the TBEV/LIV-I. ricinus PPI network, and indeed of any PPI network involving a tick-borne virus and its tick vector. While further investigation will be needed to elucidate the role of each tick protein in the replication cycle of tick-borne flaviviruses, our study provides a foundation for understanding the vector competence of I. ricinus at the molecular level. Indeed, certain PPIs may represent molecular determinants of vector competence of I. ricinus for TBEV and LIV, and potentially for other tick-borne flaviviruses.
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http://dx.doi.org/10.1186/s13071-021-04651-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7937244PMC
March 2021

Exposure of Wild Ungulates to the Usutu and Tick-Borne Encephalitis Viruses in France in 2009-2014: Evidence of Undetected Flavivirus Circulation a Decade Ago.

Viruses 2019 12 19;12(1). Epub 2019 Dec 19.

UMR (Unité mixte de recherche) Virologie, INRAE, Ecole Nationale Vétérinaire d'Alfort, ANSES, Université Paris-Est, 94700 Maisons-Alfort, France.

Flaviviruses have become increasingly important pathogens in Europe over the past few decades. A better understanding of the spatiotemporal distribution of flaviviruses in France is needed to better define risk areas and to gain knowledge of the dynamics of virus transmission cycles. Serum samples from 1014 wild boar and 758 roe deer from 16 departments (administrative units) in France collected from 2009 to 2014 were screened for flavivirus antibodies using a competitive ELISA (cELISA) technique. Serum samples found to be positive or doubtful by cELISA were then tested for antibodies directed against West Nile virus (WNV), Usutu virus (USUV), Bagaza virus (BAGV), and tick-borne encephalitis/Louping ill viruses (TBEV/LIV) by microsphere immunoassays (except BAGV) and micro-neutralization tests. USUV antibodies were detected only in southeastern and southwestern areas. TBEV/LIV antibodies were detected in serum samples from eastern, southwestern and northern departments. The results indicate continuous circulation of USUV in southern France from 2009 to 2014, which was unnoticed by the French monitoring system for bird mortality. The findings also confirm wider distribution of TBEV in the eastern part of the country than of human clinical cases. However, further studies are needed to determine the tick-borne flavivirus responsible for the seroconversion in southwestern and northern France.
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http://dx.doi.org/10.3390/v12010010DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7019733PMC
December 2019

A canine adenovirus type 2 vaccine vector confers protection against foot-and-mouth disease in guinea pigs.

Vaccine 2018 04 12;36(16):2193-2198. Epub 2018 Mar 12.

UMR Virologie, INRA, ANSES, École Nationale Vétérinaire d'Alfort, Maisons-Alfort, F-94700, France. Electronic address:

Vaccination is a key element in the control of foot-and-mouth disease (FMD). The majority of the antigenic sites that induce protective immune responses are localized on the FMD virus (FMDV) capsid that is formed by four virus-encoded structural proteins, VP1 to VP4. In the present study, recombinant canine adenovirus type 2 (CAV2)-based FMD vaccines, Cav-P1/3C R° and Cav-VP1 R°, respectively expressing the structural P1 precursor protein along with the non-structural 3C protein or expressing the structural VP1 protein of the FMDV strain O/FRA/1/2001, were evaluated as novel vaccines against FMD. A strong humoral immune response was elicited in guinea pigs (GP) following immunization with Cav-P1/3C R°, while administration of Cav-VP1 R° did not induce a satisfying antibody response in GP or mice. GP were then used as an experimental model for the determination of the protection afforded by the Cav-P1/3C R° vaccine against challenge with the FMDV strain O Manisa/Turkey/1969. The Cav-P1/3C R° vaccine protected GP from generalized FMD to a similar extent as a high potency double-oil emulsion O Manisa vaccine. The results of the present study show that CAV2-based vector vaccines can express immunogenic FMDV antigens and offer protection against generalized FMD in GP. This suggest that Cav-P1/3C R° FMDV vaccine may protect natural host species from FMD. In combination with an appropriate diagnostic test, the Cav-P1/3C R° FMDV vaccine may also serve as a marker vaccine to differentiate vaccinated from infected animals.
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http://dx.doi.org/10.1016/j.vaccine.2018.02.074DOI Listing
April 2018

Firewalls Prevent Systemic Dissemination of Vectors Derived from Human Adenovirus Type 5 and Suppress Production of Transgene-Encoded Antigen in a Murine Model of Oral Vaccination.

Front Cell Infect Microbiol 2018 25;8. Epub 2018 Jan 25.

UMR Virologie INRA, Ecole Nationale Vétérinaire d'Alfort, ANSES, Université Paris-Est, Maisons-Alfort, France.

To define the bottlenecks that restrict antigen expression after oral administration of viral-vectored vaccines, we tracked vectors derived from the human adenovirus type 5 at whole body, tissue, and cellular scales throughout the digestive tract in a murine model of oral delivery. After intragastric administration of vectors encoding firefly luciferase or a model antigen, detectable levels of transgene-encoded protein or mRNA were confined to the intestine, and restricted to delimited anatomical zones. Expression of luciferase in the form of multiple small bioluminescent foci in the distal ileum, cecum, and proximal colon suggested multiple crossing points. Many foci were unassociated with visible Peyer's patches, implying that transduced cells lay in proximity to villous rather than follicle-associated epithelium, as supported by detection of transgene-encoded antigen in villous epithelial cells. Transgene-encoded mRNA but not protein was readily detected in Peyer's patches, suggesting that post-transcriptional regulation of viral gene expression might limit expression of transgene-encoded antigen in this tissue. To characterize the pathways by which the vector crossed the intestinal epithelium and encountered sentinel cells, a fluorescent-labeled vector was administered to mice by the intragastric route or inoculated into ligated intestinal loops comprising a Peyer's patch. The vector adhered selectively to microfold cells in the follicle-associated epithelium, and, after translocation to the subepithelial dome region, was captured by phagocytes that expressed CD11c and lysozyme. In conclusion, although a large number of crossing events took place throughout the intestine within and without Peyer's patches, multiple firewalls prevented systemic dissemination of vector and suppressed production of transgene-encoded protein in Peyer's patches.
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http://dx.doi.org/10.3389/fcimb.2018.00006DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5788964PMC
January 2019

Trichinella spiralis newborn larvae: characterization of a stage specific serine proteinase expression, NBL1, using monoclonal antibodies.

Parasitology 2015 May 19;142(6):783-90. Epub 2015 Jan 19.

Animal Health Laboratory,Université Paris-Est,Anses,ENVA,JRU BIPAR,Maisons-Alfort,France.

Trichinella spiralis is an intracellular parasitic nematode of mammalian skeletal muscle, causing a serious zoonotic disease in humans and showing a high economic impact mainly in pig breeding. Serine proteinases of T. spiralis play important roles in the host-parasite interactions mediating host invasion. In this study, we have focused on newborn larvae (NBL-1), the first identified serine proteinase from the NBL stage of T. spiralis. Five monoclonal antibodies (mAbs) directed against the C-terminal part of NBL1, were produced. These mAbs were IgG1κ isotype and specifically recognized as a common motif of 10 amino acids (PSSGSRPTYP). Selected mAbs were further characterized using antigens from various developmental stages of T. spiralis. Western blot revealed that selected mAbs reacted with the native NBL1 at Mr 50 kDa in the adult and NBL mixed antigens and NBL stage alone. Indirect immunofluorescence analysis revealed that selected mAbs intensely stained only the embryos within the gravid females and the NBL. Thus, the produced mAbs are useful tools for the characterization of NBL1 as a major antigen of Trichinella involved in the invasion of the host but also for the development of new serological tests with an early detection of T. spiralis infection.
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http://dx.doi.org/10.1017/S0031182014001851DOI Listing
May 2015

Primary characterization and assessment of a T. spiralis antigen for the detection of Trichinella infection in pigs.

Vet Parasitol 2014 Oct 16;205(3-4):558-67. Epub 2014 Sep 16.

Anses, ENVA, UPEC, Laboratory for Animal Health, JRU BIPAR, 23 Avenue du Général de Gaulle, 94706 Maisons-Alfort, France.

A clone, designated L20h-Ts3, was selected by immunoscreening of cDNA libraries of Trichinella spiralis worms collected 14h, 20h and 48h post-infection (p.i.) from mice intestines. L20h-Ts3 encodes the full-length of a conserved hypothetical protein of 13.1kDa involving putative interaction with the immune system. PCR analysis showed that L20h-Ts3 mRNA is constitutively expressed throughout T. spiralis life cycle and not restricted to intestinal stages. The L20h-Ts3 fusion protein was obtained in an Escherichia coli expression system and purified by Ni-affinity chromatography before inoculation into mice in order to produce polyclonal antibodies. Then, immunohistochemical study and Western blot analysis revealed its presence within the stichosome of T. spiralis and in excretory/secretory products strengthening a putative fundamental role for the parasite's survival such as host tissue invasion or modification of the host muscular cell phenotype. L20h-Ts3 fusion protein was recognized in Western blot as soon as 15-20 days p.i. by sera from pigs experimentally infected with 20,000 muscle larvae (ML) of T. spiralis. Thus, an indirect L20h-Ts3 ELISA was designed and evaluated using sera from experimentally infected pigs by comparison with the only ELISA currently available for trichinellosis purposes. A gain of precocity from 7 up to 14 days and detection up to 25 weeks p.i. was possible with the L20h-Ts3 ELISA offering a large window for trichinellosis detection. The L20h-Ts3 ELISA was less effective in the case of low infections in pigs. Nevertheless, these results show that the L20h-Ts3 ELISA has a real interest due to its precocity and stability of detection in time. The association of the L20h-Ts3 fusion protein with other antigenic proteins identified previously could appreciably improve the serological test and facilitate its standardization.
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http://dx.doi.org/10.1016/j.vetpar.2014.09.004DOI Listing
October 2014

Increasing circulation of Alaria alata mesocercaria in wild boar populations of the Rhine valley, France, 2007-2011.

Vet Parasitol 2014 Jan 29;199(3-4):153-9. Epub 2013 Sep 29.

Epidemiology Unit, French Agency for Food, Environmental and Occupational Health and Safety, Laboratory for Animal Health, 23 avenue du Général de Gaulle, 94706 Maisons-Alfort Cedex, Maisons-Alfort, France. Electronic address:

The presence of the mesocercarial stage of Alaria alata (Goeze, 1792) in wild boar meat represents a potential risk for human, but little is known about the circulation of mesocercaria in wild boar populations. Routine Trichinella inspection, mandatorily performed in wild boar in France, also allowed detecting mesocercaria. We analyzed the results of this detection in the carcasses of 27,582 wild boars hunted in 2007-2011, in 502 hunting areas of the Rhine valley. Prevalence was globally low (0.6%), but 12% of the hunting areas were affected. These were clustered in lowlands of the Rhine valley, and prevalence strongly decreased with increasing elevation. In the lowlands, prevalence doubled between 2007 and 2011. This time trend and the geographic aggregation of positive wild boars suggest risk management measures based on targeted surveillance, control and prevention.
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http://dx.doi.org/10.1016/j.vetpar.2013.09.029DOI Listing
January 2014

Freeze-tolerance of Trichinella muscle larvae in experimentally infected wild boars.

Vet Parasitol 2013 May 5;194(2-4):175-8. Epub 2013 Feb 5.

ANSES, Laboratory for Animal Health, JRU BIPAR, 23 avenue du Général de Gaulle, 94700 Maisons Alfort, France.

Freeze-tolerance of encapsulated Trichinella muscle larvae (ML) is mainly determined by Trichinella species, but is also influenced by host species, the age of the infection and the storage time and temperature of the infected meat. Moreover, the freeze-tolerance of the encapsulated species appears to be correlated to the development of thick capsule walls which increases with age. An extended infection period and the muscle composition in some hosts (e.g. herbivores) may provide freeze-avoiding matrices due to high carbohydrate contents. The present experiment compares freeze-tolerance of Trichinella spiralis and Trichinella britovi ML in wild boar meat 24 weeks post inoculation (wpi). Three groups of four wild boars were infected with 200, 2000 or 20,000 ML of T. britovi (ISS 1575), respectively. Additionally, three wild boars were inoculated with 20,000 ML of T. spiralis (ISS 004) and two animals served as negative controls. All wild boars were sacrificed 24 wpi. Muscle samples of 70 g were stored at -21°C for 19, 30 and 56 h, and for 1-8 weeks. Larvae were recovered by artificial digestion. Their mobilities were recorded using Saisam(®) image analysis software and their infectivities were evaluated using mouse bioassays. Samples frozen for 19, 30 and 56 h allowed recovery of mobile ML, but samples frozen for 1 or 2 weeks did not. Correspondingly, only T. spiralis and T. britovi larvae isolated from wild boar meat frozen for 19, 30 and 56 h established in mice. This study showed that freezing at -21°C for 1 week inactivated T. spiralis and T. britovi ML encapsulated in wild boar meat for 24 weeks.
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http://dx.doi.org/10.1016/j.vetpar.2013.01.049DOI Listing
May 2013

Molecular characterization of Ancylostoma braziliense larvae in a patient with hookworm-related cutaneous larva migrans.

Am J Trop Med Hyg 2012 May;86(5):843-5

Département des Maladies Infectieuses et Tropicales, Hôpital Universitaire de la Pitié-Salpêtrière, Paris, France.

We report a case of hookworm-related cutaneous larva migrans diagnosed microscopically. Viable hookworm larvae were found by microscopic examination of a skin scraping from follicular lesions. Amplification and sequencing of the internal transcribed spacer 2 allowed the specific identification of the larvae as Ancylostoma braziliense.
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http://dx.doi.org/10.4269/ajtmh.2012.11-0734DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3335691PMC
May 2012

Screening for Trichinella britovi infection in red fox (Vulpes vulpes) and wild boar (Sus scrofa) in southeastern France.

J Wildl Dis 2012 Jan;48(1):223-5

Cabinet Médical, 12(e) Régiment de Cuirassiers, Quartier Valmy, BP 119, 45161 Olivet Cedex, France.

From 2006 to 2009 we screened 108 red foxes (Vulpes vulpes) and 894 wild boars (Sus scrofa) in Haut-Var, France for Trichinella britovi infection. Prevalences were 2.7 and 0% respectively. The fox may be considered a predictive sentinel for Trichinella in the Haut-Var ecosystem.
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http://dx.doi.org/10.7589/0090-3558-48.1.223DOI Listing
January 2012

Identification of Trichinella spiralis early antigens at the pre-adult and adult stages.

Parasitology 2011 Apr 19;138(4):463-71. Epub 2010 Nov 19.

AFSSA, ENVA, UPEC, LERPAZ, JRU BIPAR, 23 avenue du Général de Gaulle, 94700 Maisons-Alfort, France.

Three expression cDNA libraries from Trichinella spiralis worms 14 h, 20 h and 48 h post-infection (p.i.) were screened with serum from pigs experimentally infected with 20,000 T. spiralis muscle larvae. Twenty-nine positive clones were isolated from the 14 h p.i. cDNA library, corresponding to 8 different genes. A putative excretory-secretory protein similar to that of T. pseudospiralis was identified. Three clones corresponded to a T. spiralis serine proteinase inhibitor known to be involved in diverse functions such as blood coagulation and modulation of inflammation. Screening of the 20 h p.i. cDNA library selected 167 positive clones representing 12 different sequences. The clone with the highest redundancy encoded a small polypeptide having no sequence identity with any known proteins from Trichinella or other organisms. Fourteen clones displayed sequence identity with the heat shock protein (HSP) 70. HSPs are produced as an adaptive response of the parasite to the hostile environment encountered in the host intestine but their mechanism of action is not yet well defined. From the 48 h p.i. T. spiralis cDNA library, 91 positive clones were identified representing 7 distinct sequences. Most of the positive clones showed high similarity with a member of a putative T. spiralis serine protease family. This result is consistent with a possible major role for serine proteases during invasive stages of Trichinella infection and host-parasite interactions.
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http://dx.doi.org/10.1017/S0031182010001526DOI Listing
April 2011

Relationship between ozone and temperature during the 2003 heat wave in France: consequences for health data analysis.

BMC Public Health 2006 Oct 20;6:261. Epub 2006 Oct 20.

Inserm, U618, Tours, F-37000 France.

Background: PAPRICA is a research program designed to estimate the impact on the health of patients with chronic respiratory insufficiency of a prevention strategy based on notification of ozone pollution. The first year of this study was conducted during the 2003 heat wave, and high temperatures were therefore considered as a confounding factor in the data analysis. The aim of the present study was to assess the relationship between ozone and temperature in order to propose a methodology to distinguish between the effects of ozone and temperature on the impact of a prevention strategy with regard to ozone pollution.

Methods: Multivariate analyses were used to identify associated climate and ozone pollution profiles. This descriptive method is of great value to highlight the complexity of interactions between these parameters.

Results: Ozone concentration and temperature were strongly correlated, but the health impact of ozone pollution alone will be evaluated by focusing on situations characterized by ozone concentrations above 110 mug/m3/8h (air quality guidelines to protect human health defined by the French legislation) and temperatures lower than 26 degrees C, below the discomfort threshold.

Conclusion: The precise relationship between ambient ozone concentration and temperature identified during the PAPRICA 2003 study period will be used in analysing the PAPRICA health data.
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http://dx.doi.org/10.1186/1471-2458-6-261DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1635711PMC
October 2006

Kinetics of the inhibition of neutrophil proteinases by recombinant elafin and pre-elafin (trappin-2) expressed in Pichia pastoris.

Eur J Biochem 2004 Jun;271(12):2370-8

INSERM U618, University François Rabelais, Tours, France.

Elafin and its precursor, trappin-2 or pre-elafin, are specific endogenous inhibitors of human neutrophil elastase and proteinase 3 but not of cathepsin G. Both inhibitors belong, together with secretory leukocyte protease inhibitor, to the chelonianin family of canonical protease inhibitors of serine proteases. A cDNA coding either elafin or its precursor, trappin-2, was fused in frame with yeast alpha-factor cDNA and expressed in the Pichia pastoris yeast expression system. Full-length elafin or full-length trappin-2 were secreted into the culture medium with high yield, indicating correct processing of the fusion proteins by the yeast KEX2 signal peptidase. Both recombinant inhibitors were purified to homogeneity from concentrated culture medium by one-step cationic exchange chromatography and characterized by N-terminal amino acid sequencing, Western blot and kinetic studies. Both recombinant elafin and trappin-2 were found to be fast-acting inhibitors of pancreatic elastase, neutrophil elastase and proteinase 3 with k(ass) values of 2-4 x 10(6) m(-1).s(-1), while dissociation rate constants k(diss) were found to be in the 10(-4) s(-1) range, indicating low reversibility of the complexes. The equilibrium dissociation constant K(i) for the interaction of both recombinant inhibitors with their target enzymes was either directly measured for pancreatic elastase or calculated from k(ass) and k(diss) values for neutrophil elastase and proteinase 3. K(i) values were found to be in the 10(-10) molar range and virtually identical for both inhibitors. Based on the kinetic parameters determined here, it may be concluded that both recombinant elafin and trappin-2 may act as potent anti-inflammatory molecules and may be of therapeutic potential in the treatment of various inflammatory lung diseases.
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http://dx.doi.org/10.1111/j.1432-1033.2004.04156.xDOI Listing
June 2004