Protective Efficacy of an Inactivated Recombinant Serotype 4 Fowl Adenovirus Against Duck Adenovirus 3 in Muscovy Duck.

Background: Duck adenovirus 3 (DAdV-3) is an emerging pathogen that has caused severe economic losses to the duck industry in China. Recently, the infection of ducks with serotype 4 fowl adenovirus (FAdV-4) has also been reported in China. Therefore, an efficient bivalent vaccine to control the diseases caused by DAdV-3 and FAdV-4 is extremely urgent.

Identification of key residues of B cell epitopes in hemagglutinin of H6 influenza A virus.

Since the escape immunity of influenza A viruses (IAVs) is mainly caused by the continuous antigenic variations in HA, the identification of key antigenic epitopes is crucial for better understanding of the escape immunity and vaccine development for IAVs. The antigenic sites of several HA subtypes, including H1, H3, H5, and H9, have been well characterized, whereas those of H6 subtype are poorly understood. Here, we mapped nine key residues of antigenic epitopes in H6 through escape mutants using a panel of MAbs.

A novel mAb broadly neutralizes SARS-CoV-2 VOCs in vitro and in vivo, including the Omicron variants.

Novel immune escape variants have emerged as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to spread worldwide. Many of the variants cause breakthrough infections in vaccinated populations, posing great challenges to current antiviral strategies targeting the immunodominance of the receptor-binding domain within the spike protein. Here, we found that a novel broadly neutralizing monoclonal antibody (mAb), G5, provided efficient protection against SARS-CoV-2 variants of concern (VOCs) in vitro and in vivo.

Amino Acid Variation at Hemagglutinin Position 193 Impacts the Properties of H9N2 Avian Influenza Virus.

Despite active control strategies, including the vaccination program in poultry, H9N2 avian influenza viruses possessing mutations in hemagglutinin (HA) were frequently isolated. In this study, we analyzed the substitutions at HA residue 193 (H3 numbering) of H9N2 and investigated the impact of these mutations on viral properties. Our study indicated that H9N2 circulating in the Chinese poultry have experienced frequent mutations at HA residue 193 since 2013, with viruses that carried asparagine (N) being replaced by those with alanine (A), aspartic acid (D), glutamic acid (E), glycine (G), and serine (S), etc.

FAdV-4 without Is a Highly Attenuated and Protective Vaccine Candidate.

Hepatitis-hydropericardium syndrome (HHS) caused by the highly pathogenic fowl adenovirus serotype 4 (FAdV-4) has resulted in huge economic losses to the poultry industry globally. The gene, as a major virulence determiner, is also an important vaccine target against FAdV-4. In this study, we used a CRISPR/Cas9-based homology-dependent recombinant technique to replace the gene with and generate a novel recombinant virus, designated FAdV4-EGFP-rF2.

Synergistic pathogenesis of chicken infectious anemia virus and J subgroup of avian leukosis virus.

As important immunosuppressive viruses, chicken infectious anemia virus (CIAV) and subgroup J avian leukosis virus (ALV-J) have caused huge economic losses to the poultry industry globally. Recently, the co-infection of CIAV and ALV-J frequently occurred in the domestic chicken flocks in China. However, the synergistic pathogenesis of CIAV and ALV-J has not been fully investigated.

Characterization of Subtype H6 Avian Influenza A Viruses Isolated From Wild Birds in Poyang Lake, China.

Subtype H6 avian influenza A viruses (IAVs) are enzootic and genetically diverse in both domestic poultry and wild waterfowl and may cause spillovers in both pigs and humans. Thus, it is important to understand the genetic diversity of H6 IAVs in birds and their zoonotic potential. Compared with that in domestic poultry, the genetic diversity of H6 viruses in wild birds in China has not been well-understood.

A novel fiber-2-edited live attenuated vaccine candidate against the highly pathogenic serotype 4 fowl adenovirus.

Recently, the outbreaks of hydropericardium-hepatitis syndrome (HHS) caused by the highly pathogenic fowl adenovirus serotype 4 (FAdV-4) have resulted in huge economic losses to the poultry industry globally. Although several inactivated or subunit vaccines have been developed against FAdV-4, live-attenuated vaccines for FAdV-4 are rarely reported. In this study, a recombinant virus FA4-EGFP expressing EGFP-Fiber-2 fusion protein was generated by the CRISPR/Cas9 technique.

Domain in Fiber-2 interacted with KPNA3/4 significantly affects the replication and pathogenicity of the highly pathogenic FAdV-4.

The outbreaks of hepatitis-hydropericardium syndrome (HPS) caused by the highly pathogenic serotype 4 fowl adenovirus (FAdV-4) have caused a huge economic loss to the poultry industry globally since 2013. Although the Fiber-2 has been identified as a key virulent related factor for FAdV-4, little is known about its molecular basis. In this study, we identified the efficient interaction of the Fiber-2 with the karyopherin alpha 3/4 (KPNA3/4) protein via its N-terminus of 1-40aa.