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Lentiviruses inefficiently incorporate human parainfluenza type 3 envelope proteins

Cindy Jung1, Joseph M Le Doux

  • 1The Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University, Atlanta, Georgia 30332-0535, USA.

Biotechnology and Bioengineering
|August 21, 2007
PubMed

Insights

Low titers of human parainfluenza virus type 3 (HPIV3) lentiviral vectors are not due to insufficient envelope protein expression. Instead, limited incorporation of these HPIV3 proteins into lentiviruses hinders efficient cell transduction.

Area of Science:

  • Virology
  • Gene Therapy
  • Molecular Biology

Background:

  • Human parainfluenza virus type 3 (HPIV3) envelope glycoproteins (F and HN) can pseudotype lentiviruses.
  • Current HPIV3-pseudotyped lentiviruses exhibit low titers, limiting their clinical gene transfer applications.

Purpose of the Study:

  • Investigate the reasons behind low titers of HPIV3-pseudotyped lentiviruses.
  • Determine strategies to enhance the efficiency of HPIV3-based lentiviral vectors for gene therapy.

Main Methods:

  • Compared mRNA and protein expression of HPIV3 F and HN glycoproteins in transfected cells versus wild-type HPIV3-infected cells.
  • Utilized codon optimization of the HN gene to enhance its expression in lentivirus producer cells.
  • Quantified cell-surface protein levels, viral incorporation, virus titers, and transduction efficiency.

Main Results:

  • Transfected cells showed similar mRNA levels but lower cell-surface F and HN protein expression compared to infected cells.
  • Codon optimization of HN increased cell-surface expression, viral incorporation, and virus titers (1.2- to 6.4-fold).
  • HPIV3 pseudotyped lentiviruses incorporated significantly fewer envelope proteins than amphotropic lentiviruses.

Conclusions:

  • Low titers of HPIV3-pseudotyped lentiviruses are primarily due to inefficient incorporation of envelope glycoproteins into the viral particles, not low expression in producer cells.
  • Codon optimization can improve HPIV3 envelope protein expression and vector titers.
  • Further optimization is needed to increase envelope protein incorporation for enhanced gene transfer efficiency.

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