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Characterization of the host cell entry of filamentous influenza virus

S B Sieczkarski1, G R Whittaker

  • 1Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA.

Archives of Virology
|June 17, 2005
PubMed

Insights

Influenza virus entry differs by shape. Filamentous influenza virus particles show delayed, dynamin-independent uptake, unlike spherical forms, impacting in vivo infection understanding.

Area of Science:

  • Virology
  • Cell Biology
  • Infectious Diseases

Background:

  • Laboratory influenza virus strains are typically spherical (approx. 100 nm) and enter cells via pH-dependent endocytosis.
  • Influenza virus in infected lungs often exists as filamentous particles (up to several micrometers).

Purpose of the Study:

  • To characterize the host cell entry mechanism of purified filamentous influenza virus particles.
  • To compare the entry of filamentous influenza virus with its spherical counterpart.

Main Methods:

  • Comparative analysis of spherical and filamentous influenza virus particle internalization.
  • Use of vacuolar-ATPase inhibitor to assess pH dependence.
  • Assessment of protein kinase C function in viral trafficking.
  • Investigation of dynamin involvement in endocytosis.

Main Results:

  • Internalization of filamentous influenza virus particles is delayed compared to spherical particles, due to morphology, not strain differences.
  • Filamentous particles retain pH dependence for entry and traffic to late endosomes.
  • Endocytic uptake of filamentous influenza virus particles appears to be dynamin-independent, contrasting with spherical virions.

Conclusions:

  • Filamentous influenza virus morphology influences its cellular entry pathway.
  • Differences in entry mechanisms between filamentous and spherical influenza virions highlight in vivo versus in vitro variations.
  • This study provides insights into the distinct endocytosis of filamentous influenza virus in vivo.

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