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

• Published in: The Journal of clinical investigation Vol. 119; no. 6; pp. 1688 - 1695
• Main Authors: Pien, Gary C., Basner-Tschakarjan, Etiena, Hui, Daniel J., Mentlik, Ashley N., Finn, Jonathan D., Hasbrouck, Nicole C., Zhou, Shangzhen, Murphy, Samuel L., Maus, Marcela V., Mingozzi, Federico, Orange, Jordan S., High, Katherine A.
• Format: Journal Article
• Language: English
• Published: United States American Society for Clinical Investigation 01.06.2009
• Subjects: Antigen presentation; Antigen Presentation - immunology; Biomedical research; Capsid Proteins - immunology; Capsid Proteins - metabolism; Care and treatment; Cell Line; Clinical trials; Cloning; Cytotoxicity, Immunologic - immunology; Dependovirus - genetics; Flow cytometry; Gene therapy; Genetic aspects; Genetic transformation; Genetic Vectors - genetics; Health aspects; Hemophilia; Hepatocytes - cytology; Hepatocytes - immunology; Hepatocytes - metabolism; Histocompatibility Antigens - immunology; Humans; Liver cells; Lymphocytes; Methods; Microscopy; Peptides; Physiological aspects; Protein Multimerization; Reagents; Receptors, Antigen, T-Cell - immunology; Risk factors; Solubility; Substrate Specificity; T cells; T-Lymphocytes, Cytotoxic - immunology; United States
• ISSN: 0021-9738; 1558-8238; 1558-8238
• DOI: 10.1172/JCI36891

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.