tetano
Editor, Senior Moderator
Emerg Microbes Infect. 2020 Dec;9(1):95-110. doi: 10.1080/22221751.2019.1708215. [h=1]Contribution of Fc-dependent cell-mediated activity of a vestigial esterase-targeting antibody against H5N6 virus infection.[/h]
Zheng Z[SUP]1[/SUP], Teo SHC[SUP]1,[/SUP][SUP]2[/SUP], Arularasu SC[SUP]1[/SUP], Liu Z[SUP]1[/SUP], Mohd-Ismail NK[SUP]1[/SUP], Mok CK[SUP]1[/SUP], Ong CB[SUP]2[/SUP], Chu JJ[SUP]1,[/SUP][SUP]2[/SUP], Tan YJ[SUP]1,[/SUP][SUP]2[/SUP].
[h=3]Author information[/h] 1 Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University Health System (NUHS), National University of Singapore, Singapore, Singapore. 2 Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore.
[h=3]Abstract[/h] The highly pathogenic avian influenza A (H5N6) virus has caused sporadic human infections with a high case fatality rate. Due to the continuous evolution of this virus subtype and its ability to transmit to humans, there is an urgent need to develop effective antiviral therapeutics. In this study, a murine monoclonal antibody 9F4 was shown to display broad binding affinity against H5Nx viruses. Furthermore, 9F4 can neutralize H5N6 pseudotyped particles and prevent entry into host cells. Additionally, ADCC/ADCP deficient L234A, L235A (LALA) and CDC deficient K322A mutants were generated and displayed comparable binding affinity and neutralizing activity as wild type 9F4 (9F4-WT). Notably, 9F4-WT, 9F4-LALA and 9F4-K322A exhibit in vivo protective efficacies against H5N6 infections in that they were able to reduce viral loads in mice. However, only 9F4-WT and 9F4-K322A but not 9F4-LALA were able to reduce viral pathogenesis in H5N6 challenged mice. Furthermore, depletion of phagocytic cells in mice lungs nullifies 9F4-WT's protection against H5N6 infections, suggesting a crucial role of the host's immune cells in 9F4 antiviral activity. Collectively, these findings reveal the importance of ADCC/ADCP function for 9F4-WT protection against HPAIV H5N6 and demonstrate the potential of 9F4 to confer protection against the reassortant H5-subtype HPAIVs.
[h=4]KEYWORDS:[/h] H5N6; Influenza A virus; antibody-dependent cellular cytotoxicity; antibody-dependent cellular phagocytosis; complement dependent cytotoxicity; monoclonal antibody 9F4; vestigial esterase domain
PMID: 31906790 DOI: 10.1080/22221751.2019.1708215
Zheng Z[SUP]1[/SUP], Teo SHC[SUP]1,[/SUP][SUP]2[/SUP], Arularasu SC[SUP]1[/SUP], Liu Z[SUP]1[/SUP], Mohd-Ismail NK[SUP]1[/SUP], Mok CK[SUP]1[/SUP], Ong CB[SUP]2[/SUP], Chu JJ[SUP]1,[/SUP][SUP]2[/SUP], Tan YJ[SUP]1,[/SUP][SUP]2[/SUP].
[h=3]Author information[/h] 1 Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University Health System (NUHS), National University of Singapore, Singapore, Singapore. 2 Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore.
[h=3]Abstract[/h] The highly pathogenic avian influenza A (H5N6) virus has caused sporadic human infections with a high case fatality rate. Due to the continuous evolution of this virus subtype and its ability to transmit to humans, there is an urgent need to develop effective antiviral therapeutics. In this study, a murine monoclonal antibody 9F4 was shown to display broad binding affinity against H5Nx viruses. Furthermore, 9F4 can neutralize H5N6 pseudotyped particles and prevent entry into host cells. Additionally, ADCC/ADCP deficient L234A, L235A (LALA) and CDC deficient K322A mutants were generated and displayed comparable binding affinity and neutralizing activity as wild type 9F4 (9F4-WT). Notably, 9F4-WT, 9F4-LALA and 9F4-K322A exhibit in vivo protective efficacies against H5N6 infections in that they were able to reduce viral loads in mice. However, only 9F4-WT and 9F4-K322A but not 9F4-LALA were able to reduce viral pathogenesis in H5N6 challenged mice. Furthermore, depletion of phagocytic cells in mice lungs nullifies 9F4-WT's protection against H5N6 infections, suggesting a crucial role of the host's immune cells in 9F4 antiviral activity. Collectively, these findings reveal the importance of ADCC/ADCP function for 9F4-WT protection against HPAIV H5N6 and demonstrate the potential of 9F4 to confer protection against the reassortant H5-subtype HPAIVs.
[h=4]KEYWORDS:[/h] H5N6; Influenza A virus; antibody-dependent cellular cytotoxicity; antibody-dependent cellular phagocytosis; complement dependent cytotoxicity; monoclonal antibody 9F4; vestigial esterase domain
PMID: 31906790 DOI: 10.1080/22221751.2019.1708215