Inhibition of influenza virus infection in human airway cell cultures by an antisense peptide-conjugated morpholino oligomer targeting the hemagglutinin-activating protease TMPRSS2

J Virol. 2011 Feb;85(4):1554-62. doi: 10.1128/JVI.01294-10. Epub 2010 Dec 1.

Abstract

Influenza A viruses constitute a major and ongoing global public health concern. Current antiviral strategies target viral gene products; however, the emergence of drug-resistant viruses highlights the need for novel antiviral approaches. Cleavage of the influenza virus hemagglutinin (HA) by host cell proteases is crucial for viral infectivity and therefore presents a potential drug target. Peptide-conjugated phosphorodiamidate morpholino oligomers (PPMO) are single-stranded-DNA-like antisense agents that readily enter cells and can act as antisense agents by sterically blocking cRNA. Here, we evaluated the effect of PPMO targeted to regions of the pre-mRNA or mRNA of the HA-cleaving protease TMPRSS2 on proteolytic activation and spread of influenza viruses in human Calu-3 airway epithelial cells. We found that treatment of cells with a PPMO (T-ex5) designed to interfere with TMPRSS2 pre-mRNA splicing resulted in TMPRSS2 mRNA lacking exon 5 and consequently the expression of a truncated and enzymatically inactive form of TMPRSS2. Altered splicing of TMPRSS2 mRNA by the T-ex5 PPMO prevented HA cleavage in different human seasonal and pandemic influenza A viruses and suppressed viral titers by 2 to 3 log(10) units, strongly suggesting that TMPRSS2 is responsible for HA cleavage in Calu-3 airway cells. The data indicate that PPMO provide a useful reagent for investigating HA-activating proteases and may represent a promising strategy for the development of novel therapeutics to address influenza infections.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bronchi / cytology
  • Cell Line
  • Cells, Cultured
  • Chick Embryo
  • Dogs
  • Epithelial Cells / virology*
  • Hemagglutinin Glycoproteins, Influenza Virus / metabolism*
  • Humans
  • Influenza A Virus, H1N1 Subtype / drug effects
  • Influenza A Virus, H1N1 Subtype / enzymology
  • Influenza A Virus, H3N2 Subtype / drug effects
  • Influenza A Virus, H3N2 Subtype / enzymology
  • Influenza A Virus, H7N1 Subtype / drug effects
  • Influenza A Virus, H7N1 Subtype / enzymology
  • Influenza A virus / drug effects*
  • Influenza A virus / enzymology
  • Influenza A virus / pathogenicity*
  • Metalloendopeptidases / metabolism*
  • Morpholines / pharmacology*
  • Morpholinos
  • RNA Precursors / genetics
  • RNA Precursors / metabolism
  • RNA Splicing
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Serine Endopeptidases / metabolism*

Substances

  • Hemagglutinin Glycoproteins, Influenza Virus
  • Morpholines
  • Morpholinos
  • RNA Precursors
  • RNA, Messenger
  • Serine Endopeptidases
  • TMPRSS2 protein, human
  • Metalloendopeptidases
  • hemagglutinin-protease