title: Cancer immunotherapy using a DNA vaccine encoding the translocation domain of a bacterial toxin linked to a tumor antigen.
abstract: Certain domains of bacterial toxins have been shown to facilitate translocation from extracellular and vesicular compartments into the cytoplasm. This feature represents an opportunity to enhance class I presentation of exogenous antigen to CD8(+) T cells. We investigated this notion by creating a novel fusion of the translocation domain (domain II) of Pseudomonas aeruginosa exotoxin A (ETA(dII)) with a model tumor antigen, human papillomavirus type 16 E7, in the context of a DNA vaccine. Our in vitro studies indicated that cells transfected with ETA(dII)/E7 DNA or dendritic cells pulsed with lysates containing ETA(dII)/E7 protein exhibited enhanced MHC class I presentation of E7 antigen. Vaccination of mice with ETA(dII)/E7 DNA generated a dramatic increase in the number of E7-specific CD8(+) T cell precursors ( approximately 30-fold compared with wild-type E7 DNA) and converted a less effective DNA vaccine into one with significant potency against human papillomavirus type 16 E7-expressing murine tumors via a CD8-dependent pathway. These results indicate that fusion of the translocation domain of a bacterial toxin to an antigen may greatly enhance vaccine potency.
authors.affiliation: Department of Pathology, The Johns Hopkins Medical Institutions, Baltimore, Maryland 21205, USA.
authors.forename: C F
authors.initials: CF
authors.lastname: Hung
authors.forename: W F
authors.initials: WF
authors.lastname: Cheng
authors.forename: K F
authors.initials: KF
authors.lastname: Hsu
authors.forename: C Y
authors.initials: CY
authors.lastname: Chai
authors.forename: L
authors.initials: L
authors.lastname: He
authors.forename: M
authors.initials: M
authors.lastname: Ling
authors.forename: T C
authors.initials: TC
authors.lastname: Wu
mesh_terms: D036002:ADP Ribose Transferases; D000818:Animals; D017951:Antigen Presentation; D000951:Antigens, Neoplasm / Q000235:genetics / Q000276:immunology*; D001427:Bacterial Toxins; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D019496:Cancer Vaccines / Q000235:genetics / Q000276:immunology*; D003713:Dendritic Cells / Q000276:immunology; D005098:Exotoxins / Q000235:genetics / Q000276:immunology*; D005260:Female; D015395:Histocompatibility Antigens Class I / Q000276:immunology; D006801:Humans; D008175:Lung Neoplasms / Q000276:immunology / Q000517:prevention & control / Q000556:secondary; D008213:Lymphocyte Activation / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D009374:Neoplasms, Experimental / Q000276:immunology / Q000628:therapy; D009856:Oncogene Proteins, Viral / Q000235:genetics / Q000276:immunology*; D050725:Papillomavirus E7 Proteins; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D014162:Transfection; D014178:Translocation, Genetic; D019444:Vaccines, DNA / Q000235:genetics / Q000276:immunology*; D037521:Virulence Factors; D000097668:Pseudomonas aeruginosa Exotoxin A
chemical_list: D036002:ADP Ribose Transferases; D000951:Antigens, Neoplasm; D001427:Bacterial Toxins; D019496:Cancer Vaccines; D005098:Exotoxins; D015395:Histocompatibility Antigens Class I; D009856:Oncogene Proteins, Viral; D050725:Papillomavirus E7 Proteins; D011993:Recombinant Fusion Proteins; D019444:Vaccines, DNA; D037521:Virulence Factors; D000097668:Pseudomonas aeruginosa Exotoxin A; C059731:oncogene protein E7, Human papillomavirus type 16