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The role of PB1-F2 in adaptation of high pathogenicity avian influenza virus H7N7 in chickens.

Authors :
Hohensee, Luise
Scheibner, David
Schäfer, Alexander
Shelton, Holly
Mettenleiter, Thomas C.
Breithaupt, Angele
Dorhoi, Anca
Abdelwhab, Elsayed M.
Blohm, Ulrike
Source :
Veterinary Research; 1/3/2024, Vol. 55 Issue 1, p1-17, 17p
Publication Year :
2024

Abstract

Avian influenza viruses (AIV) of the H7N7 subtype are enzootic in the wild bird reservoir in Europe, cause infections in poultry, and have sporadically infected humans. The non-structural protein PB1-F2 is encoded in a second open frame in the polymerase segment PB1 and its sequence varies with the host of origin. While mammalian isolates predominantly carry truncated forms, avian isolates typically express full-length PB1-F2. PB1-F2 is a virulence factor of influenza viruses in mammals. It modulates the host immune response, causing immunopathology and increases pro-inflammatory responses. The role of full-length PB1-F2 in IAV pathogenesis as well as its impact on virus adaptation and virulence in poultry remains enigmatic. Here, we characterised recombinant high pathogenicity AIV (HPAIV) H7N7 expressing or lacking PB1-F2 in vitro and in vivo in chickens. In vitro, full-length PB1-F2 modulated viability of infected chicken fibroblasts by limiting apoptosis. In chickens, PB1-F2 promoted gastrointestinal tropism, as demonstrated by enhanced viral replication in the gut and increased cloacal shedding. PB1-F2's effects on cellular immunity however were marginal. Overall, chickens infected with full-length PB1-F2 virus survived for shorter periods, indicating that PB1-F2 is also a virulence factor in bird-adapted viruses. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
09284249
Volume :
55
Issue :
1
Database :
Supplemental Index
Journal :
Veterinary Research
Publication Type :
Academic Journal
Accession number :
174579043
Full Text :
https://doi.org/10.1186/s13567-023-01257-8