Risk Assessment of the Tropism and Pathogenesis of the Highly Pathogenic Avian Influenza A/H7N9 Virus Using Ex Vivo and In Vitro Cultures of Human Respiratory Tract. (18th April 2019)

• Record Type: Journal Article
• Authors: Chan, Louisa L Y; Hui, Kenrie P Y; Kuok, Denise I T; Bui, Christine H T; Ng, Ka-chun; Mok, Chris K P; Yang, Zi-feng; Guan, Wenda; Poon, Leo L M; Zhong, Nanshan; Peiris, J S Malik; Nicholls, John M; Chan, Michael C W
• Is Part Of: Journal of infectious diseases. Volume 220:Number 4(2019)
• Page Start: 578
• Page End: 588
• Publication Date: 2019-04-18
• Subjects: alveolar epithelial cells -- H7N9 -- HPAI -- influenza -- risk assessment; Communicable diseases -- Periodicals; Diseases -- Causes and theories of causation -- Periodicals; Medicine -- Periodicals; Communicable Diseases -- Periodicals; Electronic journals; 616.9
• DOI: 10.1093/infdis/jiz165
• Languages: English
• ISSNs: 0022-1899

Abstract

Abstract: Background: Highly pathogenic avian influenza (HPAI)-H7N9 virus arising from low pathogenic avian influenza (LPAI)-H7N9 virus with polybasic amino acid substitutions in the hemagglutinin was detected in 2017. Methods: We compared the tropism, replication competence, and cytokine induction of HPAI-H7N9, LPAI-H7N9, and HPAI-H5N1 in ex vivo human respiratory tract explants, in vitro culture of human alveolar epithelial cells (AECs) and pulmonary microvascular endothelial cells (HMVEC-L). Results: Replication competence of HPAI- and LPAI-H7N9 were comparable in ex vivo cultures of bronchus and lung. HPAI-H7N9 predominantly infected AECs, whereas limited infection was observed in bronchus. The reduced tropism of HPAI-H7N9 in bronchial epithelium may explain the lack of human-to-human transmission despite a number of mammalian adaptation markers. Apical and basolateral release of virus was observed only in HPAI-H7N9- and H5N1-infected AECs regardless of infection route. HPAI-H7N9, but not LPAI-H7N9 efficiently replicated in HMVEC-L. Conclusions: Our findings demonstrate that a HPAI-H7N9 virus efficiently replicating in ex vivo cultures of human bronchus and lung. The HPAI-H7N9 was more efficient at replicating in human AECs and HMVEC-L than LPAI-H7N9 implying that endothelial tropism may involve in pathogenesis of HPAI-H7N9 disease. Abstract : We compared the replication competences of HPAI- and LPAI-H7N9, which were comparable in ex vivo cultures of human bronchus and lung. HPAI-H7N9 and H5N1 replicated to higher titers than LPAI-H7N9 in both human alveolar epithelial and pulmonary microvascular endothelial cells.