Publications by authors named "Herve Poulet"

In the human and veterinary fields, oral vaccines generate considerable interest. In dogs, these vaccines are newly developed, and understanding their mechanisms is crucial. Mesenteric lymph nodes (MLNs) and Peyer's patches (PPs) are important sites for gastrointestinal mucosal induction, yet canine MLNs lack sufficient information.

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Article Synopsis
  • Oral vaccination is effective for stimulating immune responses, with GALT and Peyer's patches being key players; however, our knowledge about these systems in dogs is still limited.
  • The research involved advanced techniques like immunofluorescence, flow cytometry, and single-cell RNA sequencing to study canine Peyer's patches and their immune cell populations.
  • The development of a specific antibody targeting canine M cells will assist in understanding how antigens enter the dog's GALT, providing insights for future studies on dog immune responses and diseases.
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(Bb) is a Gram-negative bacterium responsible for canine infectious respiratory disease complex (CIRDC). Several vaccines targeting this pathogen are currently licensed for use in dogs, but their mechanism of action and the correlates of protection are not fully understood. To investigate this, we used a rat model to examine the immune responses induced and the protection conferred by a canine mucosal vaccine after challenge.

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Feline morbillivirus (FeMV) is a recently discovered virus belonging to the genus of the virus family . Often, the virus has been detected in urine of cats with a history of urinary disease and has a worldwide distribution. Currently, it is unclear which receptor the virus uses to enter the target cells.

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Leptospirosis is a vaccine-preventable bacterial zoonotic disease caused by pathogenic Leptospira species. The efficacy of canine vaccines is assessed by challenging vaccinated and control dogs with virulent serovars of , followed by detection of in blood and urine. We assessed the consistency between results obtained for urine and blood samples from clinical studies with species-specific real-time quantitative PCR (qPCR) targeting the gene and those obtained with the reference culture method.

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A non adjuvanted vaccine against feline herpesvirus, feline calicivirus, feline panleucopenia and feline leukemia has been formulated in reduced volume (0.5 ml) with the same antigen content as the conventional 1 ml presentation. This paper reports studies evaluating the safety and the immunogenicity of this reduced volume vaccine in comparison with the conventional volume vaccine.

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Several observations in the world of comparative immunology in plants, insects, fish and eventually mammals lead to the discovery of trained immunity in the early 2010's. The first demonstrations provided evidence that innate immune cells were capable of developing memory after a first encounter with some pathogens. Trained immunity in mammals was initially described in monocytes with the Bacille Calmette-Guerin vaccine (BCG) or prototypical agonists like β-glucans.

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The mechanisms of trained immunity have been extensively described and the beneficial effects are starting to be deciphered in settings. Prototypical compounds inducing trained immunity, such as β-glucans, act through epigenetic reprogramming and metabolic changes of innate immune cells. The recent advances in this field have opened new areas for the development of Trained immunity-based adjuvants (TIbAs).

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Feline calicivirus (FCV) is a widespread and highly prevalent pathogen of domestic cats, responsible for mild upper respiratory tract disease. Outbreaks of severe virulent systemic disease (VSD) associated with FCV infection have been reported worldwide. VSD FCV strains have a broader tropism and cause a systemic vascular compromise.

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Article Synopsis
  • Epidemiological studies show that vaccines, like BCG, may lower child mortality and morbidity beyond just targeting specific diseases.
  • Recent findings indicate that trained immunity, a form of immune memory in innate cells due to epigenetic changes after initial vaccine exposure, plays a significant role in these non-specific effects.
  • Future research should focus on identifying biomarkers for these vaccine effects, potentially reshaping vaccination policies to further reduce childhood mortality globally.
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Mycoplasmas are potential contaminants that introduce undesirable changes in mammalian cell cultures. They frequently contaminate cell substrates and other starting materials used for manufacturing cell-derived biologics, such as vaccines and pharmaceutical products. Mycoplasma purity testing of live vaccines, active ingredients, raw material, and seed lots is required during vaccine production.

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The purpose of this study was to compare the efficacy of three FeLV vaccines, under identical conditions in a laboratory challenge model that closely mimics natural infection. Four groups of cats (n = 20 per group) were administered two doses of vaccine, 21 days apart, starting at 9-10 weeks of age (Purevax FeLV, Versifel FeLV, Nobivac feline 2-FeLV, and a placebo). Cats were challenged 3 weeks later with a virulent, heterologous FeLV isolate.

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The assessment of vaccine combinations, or the evaluation of the impact of minor modifications of one component in well-established vaccines, requires animal challenges in the absence of previously validated correlates of protection. As an alternative, we propose conducting a multivariate analysis of the specific immune response to the vaccine. This approach is consistent with the principles of the 3Rs (Refinement, Reduction and Replacement) and avoids repeating efficacy studies based on infectious challenges in vivo.

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Regulatory potency test for rabies vaccines requires mice vaccination followed by challenge with a live virus via intracerebral route. An alternative in vitro test, consistent with the "3R's" (Reduce, Replace, Refine) was designed to quantify active glycoprotein G using seroneutralizing monoclonal antibodies. This versatile ELISA targets well conformed neutralizing epitopes.

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Feline vaccination guidelines recommend less frequent boosters for the core vaccines (rhinotracheitis, calicivirosis and infectious panleucopenia). Most guidelines recommend boosters at 3-yearly intervals after a basic vaccination including primary vaccination and revaccination one year later. The objective of this study was to assess the duration of immunity induced by PUREVAX(®) RCPCh FeLV, a non-adjuvanted vaccine against feline rhinotracheitis, calicivirosis, infectious panleucopenia, chlamydiosis and leukemia.

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The vesivirus feline calicivirus (FCV) is a positive strand RNA virus encapsidated by an icosahedral T=3 shell formed by the viral VP1 protein. Upon its expression in the insect cell - baculovirus system in the context of vaccine development, two types of virus-like particles (VLPs) were formed, a majority built of 60 subunits (T=1) and a minority probably built of 180 subunits (T=3). The structure of the small particles was determined by x-ray crystallography at 0.

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We previously delineated a highly conserved immunosuppressive (IS) domain within murine and primate retroviral envelope proteins that is critical for virus propagation in vivo. The envelope-mediated immunosuppression was assessed by the ability of the proteins, when expressed by allogeneic tumor cells normally rejected by engrafted mice, to allow these cells to escape, at least transiently, immune rejection. Using this approach, we identified key residues whose mutation (i) specifically abolishes immunosuppressive activity without affecting the "mechanical" function of the envelope protein and (ii) significantly enhances humoral and cellular immune responses elicited against the virus.

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Objective: The early events of human immunodeficiency virus infection seem critical for progression toward disease and antiretroviral therapy initiation. We wanted to clarify some still unknown prognostic relationships between inoculum size and changes in various immunological and virological markers. Feline immunodeficiency virus infection could be a helpful model.

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Background: Multiple infections are common in natural host populations and interspecific parasite interactions are therefore likely within a host individual. As they may seriously impact the circulation of certain parasites and the emergence and management of infectious diseases, their study is essential. In the field, detecting parasite interactions is rendered difficult by the fact that a large number of co-infected individuals may also be observed when two parasites share common risk factors.

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Several felid species have been shown to be susceptible to infection with highly pathogenic avian influenza (HPAI) viruses of the H5N1 subtype. Infection of felids by H5N1 HPAI virus is often fatal, and cat-to-cat transmission has been documented. Domestic cats may then be involved in the transmission of infection to other animals but also to humans.

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Background: In natural cat populations, Feline Immunodeficiency Virus (FIV) is transmitted through bites between individuals. Factors such as the density of cats within the population or the sex-ratio can have potentially strong effects on the frequency of fight between individuals and hence appear as important population risk factors for FIV.

Methodology/principal Findings: To study such population risk factors, we present data on FIV prevalence in 15 cat populations in northeastern France.

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Many theoretical studies have proposed different causal mechanisms by which the structure of a host population could have important implications for life history traits of pathogens. However, little information is available from real systems to test these hypotheses. The domestic cat, Felis silvestris catus, whose populations exhibit a great variability in social and spatial structure, represent an ideal case study to assess this question.

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This report describes a nosocomial outbreak of feline calicivirus (FCV) associated virulent systemic disease (VSD) in a French veterinary teaching hospital in 2005. The outbreak started in March and resolved within 1 month. Signs, clinical course, clinicopathological findings and lesions were typical of FCV-induced VSD.

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