Immunogenicity and Protective Efficacy of Baculovirus-Expressed SARS-CoV-2 Envelope Protein in Mice as a Universal Vaccine Candidate.

The envelope (env) protein of SARS-CoV-2, a pivotal component of the viral architecture, plays a multifaceted role in viral assembly, replication, pathogenesis, and ion channel activity. These features make it a significant target for understanding virus-host interactions and developing vaccines to combat COVID-19. Recent structural studies provide valuable insights into the conformational dynamics and membrane topology of the SARS-CoV-2 env protein, shedding light on its functional mechanisms. The strong homology and highly conserved structure of the SARS-CoV-2 env protein shape its immunogenicity and functional characteristics. This study examines the ability of the recombinant SARS-CoV-2 env protein to stimulate an immune response. In this study, recombinant envelope proteins were produced using the baculovirus expression system, and their potential efficacy was evaluated in both in vivo and in vitro models. Our results reveal that the env protein of SARS-CoV-2 stimulates humoral and cellular responses and highlight its potential as a promising vaccine candidate for combating the ongoing pandemic.

Ovine adenoviruses infecting sheep and goats in Türkiye: detection and molecular characterization of three different types.

Adenoviruses (AdVs) have been detected in a wide variety of animals. To date, eight types of AdVs in sheep and two types in goats have been identified, which belong to two distinct genera, Mastadenovirus and Atadenovirus. Typically, the term pneumo-enteritis is used to describe adenovirus-induced disease in small ruminants, which has been associated with both enteric and respiratory symptoms of varying severity. The aim of this study was to detect and identify AdVs of small ruminants belonging to the genera Mastadenovirus and Atadenovirus. For this purpose, diagnostic samples (47 lung, 27 intestine, and two pooled tissue samples including intestine and lung) from 49 small ruminants (39 sheep and 10 goats) were used. Following the viral DNA extraction, PCR was carried out by using the primers targeting the hexon gene in order to detect both mast- and atadenoviruses. Sequencing the amplified fragments revealed the presence of three types of ovine adenovirus (OAdV): OAdV-3, OAdV-4, and OAdV-8. Specifically, OAdV-3 was detected in two sheep and a goat while OAdV-4 and OAdV-8 were found in only one sheep each. There is still limited data on the interaction between the viruses in different adenovirus genera and the detected disease, as well as the genetic diversity of adenoviruses, especially in small ruminants. In conclusion, the detection of AdVs in lung and intestinal tissues of small ruminants in this study suggests that these viruses may have contributed to the disease and/or predisposed to other agents.

Molecular characterization of picobirnaviruses in small ruminants with diarrhea in Turkey.

Picobirnaviruses (PBVs), detected in a wide range of host species, are viruses of which limited information is available about their pathogenic potential, ecology, or evolutionary characteristics. In this study, a molecular analysis of segment 2 encoding the PBV RNA-dependent RNA-polymerase (RdRp) in small ruminants with diarrhea in Turkey was undertaken. A total of 66 fecal samples or gut contents from diarrheic small ruminants including 55 sheep and 11 goats were screened. Four samples (6.06%), obtained from sheep in different farms, yielded the expected amplicon size for the genogroup I RdRp gene fragment, whereas no positivity was detected for genogroup II PBVs. Phylogenetic analysis revealed high levels of genetic diversity among the genogroup I PBVs. Additionally, all PBV infected sheep were also positive for rotavirus A. This study, reporting the presence of the PBVs in sheep Turkey for the first time, contributes to the molecular characterization and epidemiology of PBVs.

Whole-genome analysis of a rare G15P[21] group A rotavirus detected at a dairy cattle farm.

Group A rotaviruses (RVAs) are a major cause of severe enteritis in humans and animals. RVAs have been identified in several animal species and their genetic diversity, the segmented nature of their RNA genome and the ability to spill over from one species to another can generate new RVA strains. In this study, we investigated the genome constellations of an unusual, rare, bovine RVA strain, G15P[21], identified from a farm with neonatal diarrhoea of calves in 2006. In parallel, the genome constellations of other RVA strains with different G/P types identified from the same farm in the same time span (2006-2008) were analysed. The genome constellation of strain K53 was G15-P[21]-I2-R2-C2-M2-A13-N2-T9-E2-H3 and was similar, overall, to that of the other bovine RVA strains (G6/10-P[11]-I2-R2-C2-M2-A13-N2-T6-E2-H3) with the exception of the NSP3 segment (T9 vs T6). This study describes RVA genomes with different genotype combinations isolated at a farm and also contributes to the understanding of the diversity and evaluation of rotavirus in a global context.