Saint-Paul – La Poudrière

Le site de la Poudrière de Saint-Paul est localisé sur un promontoire rocheux au-dessus de la ville. Son histoire peut être retracée grâce aux recherches d’Olivier Fontaine. Cet ouvrage militaire, édifié en 1724, est l’un des plus anciens bâtiments en maçonnerie construit dans l’île de La Réunion. Il possédait deux annexes, aujourd’hui disparues, un corps de garde et une guérite. Utilisé jusque dans les années 1960, notamment par la Direction départementale des routes, il était squatté jusqu’..

Mutations on the FG surface loop of human papillomavirus type 16 major capsid protein affect recognition by both type-specific neutralizing antibodies and cross-reactive antibodies.

The aim of this study was to further characterize the conformational neutralizing epitopes present on the surface-exposed FG loop of human papillomavirus (HPV) type 16 L1 major capsid protein. We have generated previously two chimeric L1 proteins by insertion of a foreign peptide encoding an epitope of the hepatitis B core (HBc) antigen within the FG loop. In addition, three other chimeric L1 proteins were obtained by replacing three different FG loop sequences by the HBc motif and three others by point mutations. All these chimeric L1 proteins retained the ability to self-assemble into virus-like particles (VLPs), with the exception of the mutant with substitution of the L1 sequence 274-279 by the HBc motif. The eight chimeric VLPs were then analyzed for differential reactivity with a set of six HPV-16 and HPV-31 monoclonal antibodies that bound to conformational and linear epitopes. The binding patterns of these monoclonal antibodies confirmed that the FG loop contained or contributed to neutralizing conformational epitopes. The results obtained suggested that the H31.F7 antibody, an anti-HPV-31 cross-reacting and neutralizing antibody, recognized a conformational epitope situated before the 266-271 sequence. In addition, H16.E70 neutralizing antibody reactivity was reduced with L1 VLPs with an Asn to Ala point mutation at position 270, suggesting that Asn is a part of the epitope recognized by this antibody. This study contributes to the understanding of the antigenic structure of HPV-16 and -31 L1 proteins by confirming that the FG loop contributes to neutralizing epitopes and suggesting the existence of both type-specific and cross-reactive conformational epitopes within the FG loop

Characterization of the haemagglutinin properties of the H5N1 avian influenza virus that caused human infections in Cambodia

High pathogenicity avian influenza (HPAI) H5N1 is a subtype of the influenza A virus primarily found in birds. The subtype emerged in China in 1996 and has spread globally, causing significant morbidity and mortality in birds and humans. In Cambodia, a lethal case was reported in February 2023 involving an 11-year-old girl, marking the first human HPAI H5N1 infection in the country since 2014. This research examined the zoonotic potential of the human H5N1 isolate, A/Cambodia/NPH230032/2023 (KHM/23), by assessing its receptor binding, fusion pH, HA thermal stability, and antigenicity. Results showed that KHM/23 exhibits similar receptor binding and antigenicity as the early clade 2.3.2.1c HPAI H5N1 strain, and it does not bind to human-like receptors. Despite showing limited zoonotic risk, the increased thermal stability and reduced pH of fusion in KHM/23 indicate a potential threat to poultry, emphasizing the need for vigilant monitoring

Integrated Resort Scheme (IRS) : nouveau souffle pour l’économie mauricienne ou enclaves dorées pour résidents fortunés ?

Le développement de Maurice s’est appuyé sur trois piliers : le sucre, le textile et le tourisme. Si le dernier secteur poursuit sa croissance, les deux autres, en revanche, connaissent depuis 2000 des difficultés conjoncturelles suffisamment importantes pour inciter à une politique de diversification. Le textile et le sucre ne bénéficient plus des marchés préférentiels européens. Le premier doit affronter la rude concurrence des pays asiatiques à faible coût de main-d’œuvre, le second est fr..

DW. Analysis of the early immune response to infection by infectious bursal disease virus in chickens differing in their resistance to the disease. J Virol. 2015; 89: 2469–2482. doi

ABSTRACT Chicken whole-genome gene expression arrays were used to analyze the host response to infection by infectious bursal disease virus (IBDV). Spleen and bursal tissue were examined from control and infected birds at 2, 3, and 4 days postinfection from two lines that differ in their resistance to IBDV infection. The host response was evaluated over this period, and differences between susceptible and resistant chicken lines were examined. Antiviral genes, including IFNA, IFNG, MX1, IFITM1, IFITM3, and IFITM5, were upregulated in response to infection. Evaluation of this gene expression data allowed us to predict several genes as candidates for involvement in resistance to IBDV. IMPORTANCE Infectious bursal disease (IBD) is of economic importance to the poultry industry and thus is also important for food security. Vaccines are available, but field strains of the virus are of increasing virulence. There is thus an urgent need to explore new control solutions, one of which would be to breed birds with greater resistance to IBD. This goal is perhaps uniquely achievable with poultry, of all farm animal species, since the genetics of 85% of the 60 billion chickens produced worldwide each year is under the control of essentially two breeding companies. In a comprehensive study, we attempt here to identify global transcriptomic differences in the target organ of the virus between chicken lines that differ in resistance and to predict candidate resistance genes. I nfectious bursal disease virus (IBDV) is a highly contagious virus with a bisegmented double-stranded RNA (dsRNA) genome (belonging to the family Birnaviridae) which causes immunosuppression in chickens (1). Segment A contains two overlapping open reading frames, the larger of which encodes viral proteins VP2, VP3 (both structural capsid proteins), and VP4 (a viral protease). The smaller open reading frame encodes the nonstructural protein VP5. Segment B encodes VP1 which is a multifunctional polymerase. There are two known serotypes: serotype I viruses cause a range of disease severity in chickens and are further classified into classic, variant, and highly virulent strains, and serotype II viruses are nonpathogenic. Although largely controlled by vaccination, new virulent strains of the virus mean that infectious bursal disease (IBD; also known as "Gumboro" disease) still remain a threat to the poultry industry. The virus infects dividing IgM ϩ B lymphocytes and the main site of viral replication is the bursa of Fabricius, where B cells are produced (2, 3). IBDV can also infect macrophages (3-5). Infection is spread orally via contaminated feed and water (6). IBDV affects young birds, with the disease usually being diagnosed in 3-to 6-week-old birds. Younger birds do not show clinical signs but are immunosuppresse

The influences of microbial colonisation and germ-free status on the chicken TCRβ repertoire

International audienceMicrobial colonisation is paramount to the normal development of the immune system, particularly at mucosal sites. However, the relationships between the microbiome and the adaptive immune repertoire have mostly been explored in rodents and humans. Here, we report a high-throughput sequencing analysis of the chicken TCRβ repertoire and the influences of microbial colonisation on tissue-resident TCRβ+ cells. The results reveal that the microbiome is an important driver of TCRβ diversity in both intestinal tissues and the bursa of Fabricius, but not in the spleen. Of note, public TCRβ sequences (shared across individuals) make a substantial contribution to the repertoire. Additionally, different tissues exhibit biases in terms of their V family and J gene usage, and these effects were influenced by the gut-associated microbiome. TCRβ clonal expansions were identified in both colonised and germ-free birds, but differences between the groups were indicative of an influence of the microbiota. Together, these findings provide an insight into the avian adaptive immune system and the influence of the microbiota on the TCRβ repertoire

DataSheet_1_The influences of microbial colonisation and germ-free status on the chicken TCRβ repertoire.docx

Microbial colonisation is paramount to the normal development of the immune system, particularly at mucosal sites. However, the relationships between the microbiome and the adaptive immune repertoire have mostly been explored in rodents and humans. Here, we report a high-throughput sequencing analysis of the chicken TCRβ repertoire and the influences of microbial colonisation on tissue-resident TCRβ+ cells. The results reveal that the microbiome is an important driver of TCRβ diversity in both intestinal tissues and the bursa of Fabricius, but not in the spleen. Of note, public TCRβ sequences (shared across individuals) make a substantial contribution to the repertoire. Additionally, different tissues exhibit biases in terms of their V family and J gene usage, and these effects were influenced by the gut-associated microbiome. TCRβ clonal expansions were identified in both colonised and germ-free birds, but differences between the groups were indicative of an influence of the microbiota. Together, these findings provide an insight into the avian adaptive immune system and the influence of the microbiota on the TCRβ repertoire.</p