A novel human Her-2/neu chimeric molecule expressed by Listeria monocytogenes can elicit potent HLA-A2 restricted CD8-positive T cell responses and impact the growth and spread of Her-2/neu-positive breast tumors

Clin Cancer Res. 2009 Feb 1;15(3):924-32. doi: 10.1158/1078-0432.CCR-08-2283.


Purpose: The aim of this study was to efficiently design a novel vaccine for human Her-2/neu-positive (hHer-2/neu) breast cancer using the live, attenuated bacterial vector Listeria monocytogenes.

Experimental design: Three recombinant L. monocytogenes-based vaccines were generated that could express and secrete extracellular and intracellular fragments of the hHer-2/neu protein. In addition, we generated a fourth construct fusing selected portions of each individual fragment that contained most of the human leukocyte antigen (HLA) epitopes as a combination vaccine (L. monocytogenes-hHer-2/neu chimera).

Results: Each individual vaccine was able to either fully regress or slow tumor growth in a mouse model for Her-2/neu-positive tumors. All three vaccines could elicit immune responses directed toward human leukocyte antigen-A2 epitopes of hHer-2/neu. The L. monocytogenes-hHer-2/neu chimera was able to mimic responses generated by the three separate vaccines and prevent spontaneous outgrowth of tumors in an autochthonous model for Her-2/neu-positive breast cancer, induce tumor regression in transplantable models, and prevent seeding of experimental lung metastases in a murine model for metastatic breast cancer.

Conclusion: This novel L. monocytogenes-hHer-2/neu chimera vaccine proves to be just as effective as the individual vaccines but combines the strength of all three in a single vaccination. These encouraging results support future clinical trials using this chimera vaccine and may be applicable to other cancer types expressing the Her-2/neu molecule such as colorectal and pancreatic cancer.

Publication types

  • Evaluation Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antigens, Neoplasm / immunology
  • Breast Neoplasms / genetics
  • Breast Neoplasms / immunology
  • Breast Neoplasms / metabolism
  • Breast Neoplasms / therapy*
  • CD8-Positive T-Lymphocytes / immunology*
  • Cancer Vaccines / immunology
  • Cancer Vaccines / therapeutic use*
  • Genes, erbB-2*
  • Genetic Vectors
  • HLA-A2 Antigen / immunology*
  • Humans
  • Listeria monocytogenes / immunology*
  • Mice
  • Molecular Sequence Data
  • Neoplasm Transplantation
  • Peptide Fragments / immunology
  • Vaccines, Synthetic / therapeutic use*


  • Antigens, Neoplasm
  • Cancer Vaccines
  • HLA-A2 Antigen
  • Peptide Fragments
  • Vaccines, Synthetic