Determination of specific CD4 and CD8 T cell epitopes after AAV2- and AAV8-hF.IX gene therapy

Mol Ther. 2006 Feb;13(2):260-9. doi: 10.1016/j.ymthe.2005.10.006.


The application of AAV2 or AAV8 vectors for delivery of human coagulation factor IX (hF.IX) is a promising gene therapy for hemophilia B. One major limitation of this therapy is the development of antibodies and a cytotoxic T lymphocyte (CTL) response against both the vector capsid and the transgene. We determined the class I and class II MHC peptide epitopes for AAV2, AAV8, and hF.IX after administration of AAV-2-hF.IX or AAV8-hF.IX in H2(b) (C57BL/6), H2(d) (BALB/c), or H2(k) (C3H) strains of mice. The results indicate that the AAV2 capsid peptide AA(373-381), the AAV8 capsid peptide AA(50-58), and the hF.IX transgene peptide AA(311-319) can elicit a CTL response as indicated by an IFN-gamma ELISPOT assay and an in vivo CTL assay. Furthermore, a strong H2(k) MHC II-restricted Th1 response can be elicited in C3H mice by the AAV8 capsid peptide AA(126-140) and the hF.IX peptide AA(108-122), whereas a strong Th2 response can be elicited by the AAV2 peptide AA(475-489). These results show that specific CTL responses are generated to both AAV capsid epitopes and hF.IX epitopes after injection of AAV-hF.IX, and MHC class II epitopes derived from AAV-hF.IX promote development of either Th1 or Th2 cells.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Animals
  • CD4-Positive T-Lymphocytes / immunology*
  • CD4-Positive T-Lymphocytes / metabolism
  • CD4-Positive T-Lymphocytes / virology
  • Capsid Proteins / genetics
  • Capsid Proteins / metabolism
  • Dependovirus / genetics*
  • Dependovirus / immunology*
  • Dependovirus / metabolism
  • Epitopes, T-Lymphocyte / metabolism*
  • Factor IX / metabolism
  • Female
  • Genetic Therapy* / methods
  • H-2 Antigens / metabolism
  • Histocompatibility Antigens Class II / metabolism
  • Humans
  • Mice
  • Mice, Inbred BALB C
  • Mice, Inbred C3H
  • Mice, Inbred DBA
  • Mice, Knockout
  • Molecular Sequence Data
  • Protein Binding / immunology
  • T-Lymphocytes, Cytotoxic / immunology*
  • T-Lymphocytes, Cytotoxic / metabolism
  • T-Lymphocytes, Cytotoxic / virology


  • Capsid Proteins
  • Epitopes, T-Lymphocyte
  • H-2 Antigens
  • H-2E(k) antigen
  • H-2Kb protein, mouse
  • Histocompatibility Antigens Class II
  • I-E-antigen
  • antigen H-2A(k)
  • Factor IX