TY - JOUR TI - Increased public health threat of avian-origin H3N2 influenza virus caused by its evolution in dogs AU - Chen, Mingyue AU - Lyu, Yanli AU - Wu, Fan AU - Zhang, Ying AU - Li, Hongkui AU - Wang, Rui AU - Liu, Yang AU - Yang, Xinyu AU - Zhou, Liwei AU - Zhang, Ming AU - Tong, Qi AU - Sun, Honglei AU - Pu, Juan AU - Liu, Jinhua AU - Sun, Yipeng A2 - Sawyer, Sara L A2 - Wan, Hongquan VL - 12 PY - 2023 DA - 2023/04/06 SP - e83470 C1 - eLife 2023;12:e83470 DO - 10.7554/eLife.83470 UR - https://doi.org/10.7554/eLife.83470 AB - Influenza A viruses in animal reservoirs repeatedly cross species barriers to infect humans. Dogs are the closest companion animals to humans, but the role of dogs in the ecology of influenza viruses is unclear. H3N2 avian influenza viruses were transmitted to dogs around 2006 and have formed stable lineages. The long-term epidemic of avian-origin H3N2 virus in canines offers the best models to investigate the effect of dogs on the evolution of influenza viruses. Here, we carried out a systematic and comparative identification of the biological characteristics of H3N2 canine influenza viruses (CIVs) isolated worldwide over 10 years. We found that, during adaptation in dogs, H3N2 CIVs became able to recognize the human-like SAα2,6-Gal receptor, showed gradually increased hemagglutination (HA) acid stability and replication ability in human airway epithelial cells, and acquired a 100% transmission rate via respiratory droplets in a ferret model. We also found that human populations lack immunity to H3N2 CIVs, and even preexisting immunity derived from the present human seasonal influenza viruses cannot provide protection against H3N2 CIVs. Our results showed that canines may serve as intermediates for the adaptation of avian influenza viruses to humans. Continuous surveillance coordinated with risk assessment for CIVs is necessary. KW - canine h3n2 influenza virus KW - airborne transmissibility KW - HA KW - PB1 KW - public health JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -