Induction of therapeutic T-cell responses to subdominant tumor-associated viral oncogene after immunization with replication-incompetent polyepitope adenovirus vaccine

Cancer Res. 2004 Feb 15;64(4):1483-9. doi: 10.1158/0008-5472.can-03-2196.

Abstract

The EBV-encoded latent membrane proteins (LMP1 and LMP2), which are expressed in various EBV-associated malignancies have been proposed as a potential target for CTL-based therapy. However, the precursor frequency for LMP-specific CTL is generally low, and immunotherapy based on these antigens is often compromised by the poor immunogenicity and potential threat from their oncogenic potential. Here we have developed a replication- incompetent adenoviral vaccine that encodes multiple HLA class I-restricted CTL epitopes from LMP1 and LMP2 as a polyepitope. Immunization with this polyepitope vaccine consistently generated strong LMP-specific CTL responses in HLA A2/K(b) mice, which can be readily detected by both ex vivo and in vivo T-cell assays. Furthermore, a human CTL response to LMP antigens can be rapidly expanded after stimulation with this recombinant polyepitope vector. These expanded T cells displayed strong lysis of autologous target cells sensitized with LMP1 and/or LMP2 CTL epitopes. More importantly, this adenoviral vaccine was also successfully used to reverse the outgrowth of LMP1-expressing tumors in HLA A2/K(b) mice. These studies demonstrate that a replication-incompetent adenovirus polyepitope vaccine is an excellent tool for the induction of a protective CTL response directed toward multiple LMP CTL epitopes restricted through common HLA class I alleles prevalent in different ethnic groups where EBV-associated malignancies are endemic.

MeSH terms

  • Adenoviridae / genetics
  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Cell Line
  • Epitopes, T-Lymphocyte
  • H-2 Antigens / immunology
  • Hodgkin Disease / therapy*
  • Humans
  • Immunization
  • Mice
  • Molecular Sequence Data
  • Nasopharyngeal Neoplasms / therapy*
  • T-Lymphocytes, Cytotoxic / immunology*
  • Vaccines, Synthetic / therapeutic use*
  • Viral Matrix Proteins / genetics
  • Viral Matrix Proteins / immunology*
  • Viral Vaccines / therapeutic use*
  • Virus Replication

Substances

  • EBV-associated membrane antigen, Epstein-Barr virus
  • Epitopes, T-Lymphocyte
  • H-2 Antigens
  • H-2Kb protein, mouse
  • Vaccines, Synthetic
  • Viral Matrix Proteins
  • Viral Vaccines