title: Immunostimulatory DNA-based vaccines induce cytotoxic lymphocyte activity by a T-helper cell-independent mechanism.
abstract: Immunostimulatory DNA sequences (ISS) contain unmethylated CpG dinucleotides within a defined motif. Immunization with ISS-based vaccines has been shown to induce high antigen-specific cytotoxic lymphocyte (CTL) activity and a Th1-biased immune response. We have developed a novel ISS-based vaccine composed of ovalbumin (OVA) chemically conjugated to ISS-oligodeoxynucleotide (ODN). Protein-ISS conjugate (PIC) is more potent in priming CTL activity and Th1-biased immunity than other ISS-based vaccines. Cytotoxic lymphocyte activation by ISS-ODN-based vaccines is preserved in both CD4-/- and MHC class II-/- gene-deficient animals. Furthermore, PIC provides protection against a lethal burden of OVA-expressing tumor cells in a CD8+ cell-dependent manner. These results demonstrate that PIC acts through two unique mechanisms: T-helper-independent activation of CTL and facilitation of exogenous antigen presentation on MHC class I. This technology may have clinical applications in cancer therapy and in stimulating host defense in AIDS and chronic immunosuppression.
authors.affiliation: Department of Internal Medicine and The Sam and Rose Stein Institute for Research on Aging, University of California San Diego, La Jolla, CA 92093-0663, USA.
authors.forename: H J
authors.initials: HJ
authors.lastname: Cho
authors.forename: K
authors.initials: K
authors.lastname: Takabayashi
authors.forename: P M
authors.initials: PM
authors.lastname: Cheng
authors.forename: M D
authors.initials: MD
authors.lastname: Nguyen
authors.forename: M
authors.initials: M
authors.lastname: Corr
authors.forename: S
authors.initials: S
authors.lastname: Tuck
authors.forename: E
authors.initials: E
authors.lastname: Raz
mesh_terms: D000818:Animals; D017951:Antigen Presentation; D000951:Antigens, Neoplasm / Q000627:therapeutic use*; D019496:Cancer Vaccines / Q000627:therapeutic use*; D015226:Dinucleoside Phosphates / Q000276:immunology; D015395:Histocompatibility Antigens Class I; D051379:Mice; D008817:Mice, Mutant Strains; D009374:Neoplasms, Experimental / Q000628:therapy*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology; D014611:Vaccination; D019444:Vaccines, DNA / Q000627:therapeutic use*; D014614:Vaccines, Synthetic / Q000627:therapeutic use*
chemical_list: D000951:Antigens, Neoplasm; D019496:Cancer Vaccines; D015226:Dinucleoside Phosphates; D015395:Histocompatibility Antigens Class I; D019444:Vaccines, DNA; D014614:Vaccines, Synthetic; C015772:CpG dinucleotide