tetano
Editor, Senior Moderator
J Virol. 2015 Oct 28. pii: JVI.02275-15. [Epub ahead of print]
[h=1]Hemagglutinin stalk- and neuraminidase-specific monoclonal antibodies protect against lethal H10N8 influenza virus infection in mice.[/h] Wohlbold TJ[SUP]1[/SUP], Chromikova V[SUP]2[/SUP], Tan GS[SUP]2[/SUP], Meade P[SUP]1[/SUP], Amanat F[SUP]2[/SUP], Comella P[SUP]1[/SUP], Hirsh A[SUP]2[/SUP], Krammer F[SUP]3[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] Between November 2013 and February 2014, China reported three human cases of H10N8 influenza virus infection in the Jiangxi province, two of which were fatal. Using hybridoma technology, we isolated a panel of H10- and N8-directed mAbs and further characterized the binding reactivity of these antibodies (via ELISA) to a range of purified virus and recombinant protein substrates. The H10-directed mAbs displayed functional hemagglutination inhibition (HI) and neutralization activity and the N8-directed antibodies displayed functional neuraminidase inhibition (NI) activity against H10N8. Surprisingly, the HI-reactive H10 antibodies as well as a previously generated, group 2 HA stalk-reactive antibody demonstrated NI activity against H10N8 and an H10N7 strain; this phenomenon was absent when virus was treated with detergent, suggesting the anti-HA antibodies inhibited neuraminidase enzymatic activity through steric hindrance. We tested the prophylactic efficacy of one representative H10-reactive, N8-reactive, and group 2 HA stalk-reactive antibody in vivo using a BALB/c challenge model. All three antibodies were protective at a high dose (5 mg/kg). At a low dose (0.5 mg/kg), only the anti-N8 antibody prevented weight loss. Together, these data suggest that antibody targets other than the globular head domain of the hemagglutinin may be efficacious in preventing influenza virus-induced morbidity and mortality.
[h=4]IMPORTANCE:[/h] Avian H10N8 and H10N7 viruses have recently crossed the species barrier, causing morbidity and mortality in humans and other mammals. While these reports are likely isolated incidents, it is possible that more cases may emerge in future winter seasons, similar to H7N9. Furthermore, regular transmission of avian influenza viruses to humans increases the risk of adaptive mutations and re-assortment events, which may result in a novel virus with pandemic potential. Currently, no specific therapeutics or vaccines are available against the H10N8 influenza virus subtype. Here we generated a panel of H10- and N8-reactive mAbs. While these antibodies may practically be developed into therapeutic agents, characterizing the protective potential of mAbs that have targets other than the HA globular head domain will provide insight into novel antibody-mediated mechanisms of protection and help to better understand correlates of protection for influenza A virus infection.
Copyright ? 2015, American Society for Microbiology. All Rights Reserved.
PMID: 26512088 [PubMed - as supplied by publisher]
[h=1]Hemagglutinin stalk- and neuraminidase-specific monoclonal antibodies protect against lethal H10N8 influenza virus infection in mice.[/h] Wohlbold TJ[SUP]1[/SUP], Chromikova V[SUP]2[/SUP], Tan GS[SUP]2[/SUP], Meade P[SUP]1[/SUP], Amanat F[SUP]2[/SUP], Comella P[SUP]1[/SUP], Hirsh A[SUP]2[/SUP], Krammer F[SUP]3[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] Between November 2013 and February 2014, China reported three human cases of H10N8 influenza virus infection in the Jiangxi province, two of which were fatal. Using hybridoma technology, we isolated a panel of H10- and N8-directed mAbs and further characterized the binding reactivity of these antibodies (via ELISA) to a range of purified virus and recombinant protein substrates. The H10-directed mAbs displayed functional hemagglutination inhibition (HI) and neutralization activity and the N8-directed antibodies displayed functional neuraminidase inhibition (NI) activity against H10N8. Surprisingly, the HI-reactive H10 antibodies as well as a previously generated, group 2 HA stalk-reactive antibody demonstrated NI activity against H10N8 and an H10N7 strain; this phenomenon was absent when virus was treated with detergent, suggesting the anti-HA antibodies inhibited neuraminidase enzymatic activity through steric hindrance. We tested the prophylactic efficacy of one representative H10-reactive, N8-reactive, and group 2 HA stalk-reactive antibody in vivo using a BALB/c challenge model. All three antibodies were protective at a high dose (5 mg/kg). At a low dose (0.5 mg/kg), only the anti-N8 antibody prevented weight loss. Together, these data suggest that antibody targets other than the globular head domain of the hemagglutinin may be efficacious in preventing influenza virus-induced morbidity and mortality.
[h=4]IMPORTANCE:[/h] Avian H10N8 and H10N7 viruses have recently crossed the species barrier, causing morbidity and mortality in humans and other mammals. While these reports are likely isolated incidents, it is possible that more cases may emerge in future winter seasons, similar to H7N9. Furthermore, regular transmission of avian influenza viruses to humans increases the risk of adaptive mutations and re-assortment events, which may result in a novel virus with pandemic potential. Currently, no specific therapeutics or vaccines are available against the H10N8 influenza virus subtype. Here we generated a panel of H10- and N8-reactive mAbs. While these antibodies may practically be developed into therapeutic agents, characterizing the protective potential of mAbs that have targets other than the HA globular head domain will provide insight into novel antibody-mediated mechanisms of protection and help to better understand correlates of protection for influenza A virus infection.
Copyright ? 2015, American Society for Microbiology. All Rights Reserved.
PMID: 26512088 [PubMed - as supplied by publisher]