Avian influenza virus (AIV) H7N9 diseases have been recently reported, raising concerns about a potential pandemic. Thus, there is an urgent need for effective therapeutics for AIV H7N9 infections. Herein, camelid immunization and yeast two-hybrid techniques were used to identify potent neutralizing nanobodies (Nbs) targeting the H7 subtype hemagglutinin. First, we evaluated the binding specificity and hemagglutination inhibition activity of the screened Nbs against the H7 subtype hemagglutinin. Nb-Z77, with high hemagglutination inhibition activity was selected from the screened Nbs to optimize the yeast expression conditions and construct oligomeric forms of Nb-Z77 using various ligation methods. The oligomers Nb-Z77-Di, Nb-Z77-Tri, Nb-Z77-Fc and Nb-Z77-Foldon were successfully constructed and expressed. Nb-Z77-Di and Nb-Z77-Foldon exhibited considerably greater activity than did Nb-Z77 against H7 subtype hemagglutinin, with median effective concentrations of 384.7 and 27.33 pM and binding affinity values of 213 and 5.21 pM, respectively. Nb-Z77-Di and Nb-Z77-Foldon completely inhibited the hemagglutination activity of the inactivated virus H7-Re1 at the lowest concentration of 0.938 μg/mL. This study screened a strain of Nb with high hemagglutination inhibition activity and enhanced its antiviral activity through oligomerization, which may have great potential for developing effective agents for the prevention, diagnosis, and treatment of AIV H7 subtype infection.
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http://dx.doi.org/10.1016/j.ijbiomac.2024.131458 | DOI Listing |
A risk assessment framework was developed to evaluate the zoonotic potential of avian influenza (AI), focusing on virus mutations linked to phenotypic traits related to mammalian adaptation identified in the literature. Virus sequences were screened for the presence of these mutations and their geographical, temporal and subtype-specific trends. Spillover events to mammals (including humans) and human seroprevalence studies were also reviewed.
View Article and Find Full Text PDFJ Nanobiotechnology
January 2025
College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, China.
Background: The rapid mutation of avian influenza virus (AIV) poses a significant threat to both the poultry industry and public health. Herein, we have successfully developed an mRNA-LNPs candidate vaccine for H5 subtype highly pathogenic avian influenza and evaluated its immunogenicity and protective efficacy.
Results: In experiments on BALB/c mice, the vaccine candidate elicited strong humoral and a certain cellular immune responses and protected mice from the heterologous AIV challenge.
Viruses
January 2025
Département de Virologie, Institut Pasteur de Dakar, Dakar BP 220, Senegal.
Despite extensive experience with influenza surveillance in humans in Senegal, there is limited knowledge about the actual situation and genetic diversity of avian influenza viruses (AIVs) circulating in the country, hindering control measures and pandemic risk assessment. Therefore, as part of the "One Health" approach to influenza surveillance, we conducted active AIV surveillance in two live bird markets (LBMs) in Dakar to better understand the dynamics and diversity of influenza viruses in Senegal, obtain genetic profiles of circulating AIVs, and assess the risk of emergence of novel strains and their transmission to humans. Cloacal swabs from poultry and environmental samples collected weekly from the two LBMs were screened by RT-qPCR for H5, H7, and H9 AIVs.
View Article and Find Full Text PDFSci Immunol
January 2025
Ragon Institute of Mass General, MIT, and Harvard, Cambridge, MA 02139, USA.
Understanding the naïve B cell repertoire and its specificity for potential zoonotic threats, such as the highly pathogenic avian influenza (HPAI) H5Nx viruses, may allow prediction of infection- or vaccine-specific responses. However, this naïve repertoire and the possibility to respond to emerging, prepandemic viruses are largely undetermined. Here, we profiled naïve B cell reactivity against a prototypical HPAI H5 hemagglutinin (HA), the major target of antibody responses.
View Article and Find Full Text PDFVaccines (Basel)
January 2025
NHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China.
Background: Polypeptide vaccines have the potential to improve immune responses by targeting conserved and weakly immunogenic regions in antigens. This study aimed to identify and evaluate the efficacy of a novel influenza universal vaccine candidate consisting of multiple polypeptides derived from highly conserved regions of influenza virus proteins hemagglutinin (HA), neuraminidase (NA), and matrix protein 2 (M2).
Methods: Immunoinformatics tools were used to screen conserved epitopes from different influenza virus subtypes (H1N1, H3N2, H5N1, H7N9, H9N2, and IBV).
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