tetano
Editor, Senior Moderator
J Virol. 2015 Jan 21. pii: JVI.03014-14. [Epub ahead of print]
[h=1]A novel humanized antibody neutralizes H5N1 via two different mechanisms.[/h] Tan Y[SUP]1[/SUP], Ng Q[SUP]1[/SUP], Jia Q[SUP]1[/SUP], Kwang J[SUP]2[/SUP], He F[SUP]3[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] H5N1 HPAI virus continues to be a severe threat to public health, as well as the poultry industry, due to its high mortality and antigenic drift rate. Neutralizing monoclonal antibodies can serve as a useful tool in preventing, treating and detecting H5N1. In the present study, a humanized H5 antibody 8A8 was developed from a murine H5 monoclonal antibody (Mab). Both the humanized and mouse Mabs presented positive activity in HI, virus neutralization and IFA against a wide range of H5N1s. Interestingly, both human and murine 8A8 were able to detect H5 in western blotting under reduction conditions. Further, by sequencing escape mutants, the conformational epitope of 8A8 was found to be located within the receptor binding domain (RBD) of H5. The linear epitope of 8A8 was identified by western blotting overlapping fragments and substitution mutants of HA1. RG H5N1s with individual mutations in either the conformational or linear epitope were generated and characterized in a series of assays including HI, post-attachment and cell-cell fusion inhibition assay. The results indicate that for 8A8, virus neutralization mediated by RBD-blocking relies on the conformational epitope while binding to the linear epitope contributes to the neutralization by inhibiting membrane fusion. Taken together, we report in this study that a novel humanized H5 Mab binds to two types of epitopes on HA, leading to virus neutralization via two mechanisms.
[h=4]IMPORTANCE:[/h] Recurrence of the highly pathogenic avian influenza (HPAI) virus subtype H5N1 in humans and poultry continues to be a serious concern to public health. Preventive and therapeutic measures against influenza A viruses have received much interest in the context of global efforts to combat the current and future pandemic. Passive immune therapy is considered to be the most effective and economically prudent preventive strategy against influenza besides vaccination. It is important to develop a humanized neutralizing Mab against all clades of H5N1. For the first time, we report in this study that a novel humanized H5 Mab binds to two types of epitopes on HA, leading to virus neutralization via two mechanisms. These findings further deepen our understanding of influenza neutralization.
Copyright ? 2015, American Society for Microbiology. All Rights Reserved.
PMID: 25609802 [PubMed - as supplied by publisher]
[h=1]A novel humanized antibody neutralizes H5N1 via two different mechanisms.[/h] Tan Y[SUP]1[/SUP], Ng Q[SUP]1[/SUP], Jia Q[SUP]1[/SUP], Kwang J[SUP]2[/SUP], He F[SUP]3[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] H5N1 HPAI virus continues to be a severe threat to public health, as well as the poultry industry, due to its high mortality and antigenic drift rate. Neutralizing monoclonal antibodies can serve as a useful tool in preventing, treating and detecting H5N1. In the present study, a humanized H5 antibody 8A8 was developed from a murine H5 monoclonal antibody (Mab). Both the humanized and mouse Mabs presented positive activity in HI, virus neutralization and IFA against a wide range of H5N1s. Interestingly, both human and murine 8A8 were able to detect H5 in western blotting under reduction conditions. Further, by sequencing escape mutants, the conformational epitope of 8A8 was found to be located within the receptor binding domain (RBD) of H5. The linear epitope of 8A8 was identified by western blotting overlapping fragments and substitution mutants of HA1. RG H5N1s with individual mutations in either the conformational or linear epitope were generated and characterized in a series of assays including HI, post-attachment and cell-cell fusion inhibition assay. The results indicate that for 8A8, virus neutralization mediated by RBD-blocking relies on the conformational epitope while binding to the linear epitope contributes to the neutralization by inhibiting membrane fusion. Taken together, we report in this study that a novel humanized H5 Mab binds to two types of epitopes on HA, leading to virus neutralization via two mechanisms.
[h=4]IMPORTANCE:[/h] Recurrence of the highly pathogenic avian influenza (HPAI) virus subtype H5N1 in humans and poultry continues to be a serious concern to public health. Preventive and therapeutic measures against influenza A viruses have received much interest in the context of global efforts to combat the current and future pandemic. Passive immune therapy is considered to be the most effective and economically prudent preventive strategy against influenza besides vaccination. It is important to develop a humanized neutralizing Mab against all clades of H5N1. For the first time, we report in this study that a novel humanized H5 Mab binds to two types of epitopes on HA, leading to virus neutralization via two mechanisms. These findings further deepen our understanding of influenza neutralization.
Copyright ? 2015, American Society for Microbiology. All Rights Reserved.
PMID: 25609802 [PubMed - as supplied by publisher]