Roles of VP35, VP40 and VP24 Proteins of Ebola Virus in Pathogenic and Replication Mechanisms

Ebola epidemic is a fatal disease due to Ebola virus belonging to Filoviridae; currently the viral evolution caused more than 50% of death worldwide. Among the eight proteins of ZEBOV, there are four structural proteins VP35, VP40, VP24, and NP, which have important functions in the intercellular pathogenic mechanisms. The multi‐functionality of Ebola\u27s viral proteins allows the virus to reduce its protein number to ensure its proper functioning and keeping the compact structure of the virus. Therefore, the aim of this chapter is to study the mechanism of replication and the roles of VP30, VP35, NP, and L in this process. We provide as well to highlight the influence of the virus on the immune system and on the VP24

Ebola Virus’s Glycoproteins and Entry Mechanism

Ebola virus glycoprotein (GP) is the only protein that is expressed on the surface of the virus. The GP proteins play critical roles in the entry of virus into cell and in the evasion of the immune system. The GP gene transcript to membrane GP is constituted of two subunits GP1 and GP2, and the secretory GP (sGP). The main function of GP1/2 is to attach virus to target cell’s membrane, whereas sGP has multiple functions on Ebola pathogenesis, such as inactivate neutrophils through CD16b causing lymphocyte apoptosis and vascular dysregulation. There are many studies that focused on better understanding the GP mechanism and aim at developing new antibodies and drugs such as VSV-EBOV, cAd3-EBO Z, rVSVN4CT1 VesiculoVax, ‘C-peptide’ based on the GP2 C-heptad repeat region (CHR) targeted to endosomes (Tat-Ebo) and MBX2270. In this chapter, we discuss the Ebola viral glycoproteins, genomic organization, synthesis, and their roles and functions. On the other hand, we treat the mechanisms of pathogenicity associated with Ebola GPs

Analyse phylogénétique d'isolats du virus marocain de la clavelée basée sur le gène P32

Sheeppox virus (SPPV) is considered a highly contagious disease in sheep by the World Organization for Animal Health (OIE). It is classified with Goatpox virus (GTPV) and Lumpy skin disease virus (LSDV) within the Capripoxvirus (CaPV) genus. SPPV causes significant economic losses in endemic regions like Northern and Central Africa, Asia, India and Middle East. In Morocco, little information about the molecular characterization of SPPV is available, hence the objective of the present study is to assess the genomic relationships between Moroccan viral strains isolated from different geographic regions during several outbreaks, vaccine strains and reference strains retrieved from the NCBI Genbank, by sequencing the P32 gene. All sequences were analyzed using MEGA7 software version 7. Phylogenetic tree constructions for this gene sequences were generated using the Neighbor-Joining method. It clearly appeared that SPPV strains reported in many countries, were branched and clustered with the clade of SPPV and displayed a strong genetic relationship between them with nucleotide and amino acid identities respectively of 99-100 % and 98-100 %. These results led us to conclude that P32 gene appears highly conserved among SPPV and Capripoxvirus. For that, more genetic studies are required in order to control and understand the epidemiological situation of SPPV. Keywords: Sheeppox virus, P32 gene, Phylogenetic analysis, Capripoxvirus, Goatpox virus.La clavelée (SP) est une maladie considérée hautement contagieuse par l’Organisation Mondiale de la santé Animale (OIE). L’agent causal de la maladie (SPPV) appartient au genre des Capripoxvirus contenant ainsi le virus de la variole de chèvre (GTPV) et le virus de la maladie nodulaire cutanée (LSDV). Le SPPV cause des pertes économiques considérables dans les zones endémiques telles que l’Afrique du nord et centrale, l’Asie, l’inde et le moyen orient. Au Maroc, peu d’étude de caractérisation moléculaire du SPPV sont disponibles, d’où l’objectif du présent travail qui vise à évaluer la relation génétique entre les souches virales marocaines isolées à partir de différentes régions du Maroc durant les flambées épizootiques, des souches vaccinales et des souches de références publiées sur Genbank, et ce, par le séquençage du gène P32. Toutes les séquences sont analysées par le logiciel MEGA 7.0, l’arbre phylogénétique est généré par la méthode Neighbour-Joining. Il apparaît clairement que tous les SPPV rapportés dans la plupart des pays sont branchés et groupés dans le clade du SPPV, et ont montré une forte relation génétique entre eux avec une identité d’acides nucléiques et d’acides aminés de 99-100 % et 98-100 % respectivement. Ces résultats nous mènent à conclure que le gène P32 apparaît hautement conservé chez tous les SPPV et les Capripoxvirus. Pour cela, plus d’études génétiques sont nécessaires afin de contrôler et expliquer la situation épidémiologique du SPPV. Mots-clés: Sheeppox virus, gène P32, analyse phylogénétique, Capripoxvirus, Goatpox virus

Current situation, genetic relationship and control measures of infectious bronchitis virus variants circulating in African regions

Infectious bronchitis virus (IBV) is a major viral pathogen of commercial poultry, affecting chickens of all ages and causing major economic losses in poultry industry worldwide. Frequent points of mutations and recombination events in the S1 gene region, result in the emergence of new IBVs variants circulating in the form of several serotypes/genotypes that can be partially or poorly neutralized by current vaccines. IBV is well studied worldwide, nevertheless in African countries epidemiological and scientific data are poor and not updated. This review aims to give a current overview of IBV situation, to establish evolutionary relationship between the African variants and to list some of the potential measures to control IBV in Africa. Three S1 gene hypervariable regions were studied and compared to the reference genotypes/serotypes that found emerging in African regions. This comparison was based on phylogenetic trees, nucleotide and amino-acid sequence analysis. It clearly appears that IBV variants reported in Africa, display a low genetic relationship between them and with the majority of the reference strains emerging in neighboring countries, except the case of variants from Libya and Egypt that show a high relatedness. Also the Massachusetts serotypes were the most prevalent co-circulating with both serotypes, Italy02 type in Morocco and Qx-like genotype in South part of the African continent. In order to control the IBV variants in African regions, an efficient vaccination strategy program should be implemented

Prevalence and molecular characterization of avian infectious bronchitis virus in poultry flocks in Morocco from 2010 to 2014 and first detection of Italy 02 in Africa

The aim of this study was to investigate the prevalence and diversity of infectious bronchitis virus (IBV) genotypes in poultry flocks in 16 areas of Morocco between 2010 and 2014. A total of 360 chicken flocks suspected of being infected by IBV were screened for the IBV N gene using real-time reverse transcriptase-polymerase chain reaction (RT-PCR). Flocks were classified into four groups according to their IBV vaccination programme. Group 1 contained unvaccinated birds. Group 2 received a single application of live H120 vaccine. Groups 3 and 4 birds received one or two booster vaccination(s), respectively, mostly using the H120 vaccine. The real-time RT-PCR results showed that 51.7% of the flocks were positive for the IBV genome with geographical disparities. Molecular characterization of IBV was performed on 50 RT-PCR positive samples by partially sequencing the S1 gene, including the hypervariable regions (nucleotides 705-1097). Two predominant genotypes were detected, with the Massachusetts type dominating (66%), among which 25% of the samples were identical to the H120 vaccine. The second most common genotype (present in 32% of the flocks) was surprisingly Italy 02, revealing the first detection of this genotype in Morocco and also in Africa. 793B, the predominant genotype in the late 1990s in Morocco, was only detected on one occasion and was identical to the 4/91 vaccine strain. This study highlights the high prevalence of IBV in poultry farms in Morocco and confirms its continuous dynamic changes and evolution