Capsid antigen presentation flags human hepatocytes for destruction after transduction by adeno-associated viral vectors

J Clin Invest. 2009 Jun;119(6):1688-95. doi: 10.1172/JCI36891. Epub 2009 May 11.


Adeno-associated virus (AAV) vectors are effective gene delivery vehicles mediating long-lasting transgene expression. Data from a clinical trial of AAV2-mediated hepatic transfer of the Factor IX gene (F9) into hemophilia B subjects suggests that CTL responses against AAV capsid can eliminate transduced hepatocytes and prevent long-term F9 expression. However, the capacity of hepatocytes to present AAV capsid-derived antigens has not been formally demonstrated, nor whether transduction by AAV sensitizes hepatocytes for CTL-mediated destruction. To investigate the fate of capsids after transduction, we engineered a soluble TCR for the detection of capsid-derived peptide:MHC I (pMHC) complexes. TCR multimers exhibited antigen and HLA specificity and possessed high binding affinity for cognate pMHC complexes. With this reagent, capsid pMHC complexes were detectable by confocal microscopy following AAV-mediated transduction of human hepatocytes. Although antigen presentation was modest, it was sufficient to flag transduced cells for CTL-mediated lysis in an in vitro killing assay. Destruction of hepatocytes was inhibited by soluble TCR, demonstrating a possible application for this reagent in blocking undesirable CTL responses. Together, these studies provide a mechanism for the loss of transgene expression and transient elevations in aminotransferases following AAV-mediated hepatic gene transfer in humans and a potential therapeutic intervention to abrogate these limitations imposed by the host T cell response.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigen Presentation / immunology*
  • Capsid Proteins / immunology*
  • Capsid Proteins / metabolism
  • Cell Line
  • Cytotoxicity, Immunologic / immunology*
  • Dependovirus / genetics*
  • Genetic Vectors / genetics*
  • Hepatocytes / cytology
  • Hepatocytes / immunology*
  • Hepatocytes / metabolism*
  • Histocompatibility Antigens / immunology
  • Humans
  • Protein Multimerization
  • Receptors, Antigen, T-Cell / immunology
  • Solubility
  • Substrate Specificity
  • T-Lymphocytes, Cytotoxic / immunology


  • Capsid Proteins
  • Histocompatibility Antigens
  • Receptors, Antigen, T-Cell