title: Exosomes derived from tumor cells genetically modified to express Mycobacterium tuberculosis antigen: a novel vaccine for cancer therapy.
abstract: OBJECTIVE
  To examine the potential of exosomes derived from the tumor cells, which had been genetically modified to express a Mycobacterium tuberculosis antigen, as a cancer vaccine aimed at overcoming the weak immunogenicity of tumor antigens.
  
  
  RESULTS
  We transfected B16 melanoma cells with a plasmid encoding the M. tuberculosis antigen, early secretory antigenic target-6 (ESAT-6). The secreted exosomes bearing both tumor-associated antigens and the pathogenic antigen (or their epitopes) were collected. When the exosomes were injected into foot pads of mice, they significantly (p < 0.05) evoked cellular immunity against both ESAT-6, and B16 tumor cells. Intra-tumoral injection of the exosomes significantly suppressed (p < 0.001) tumor growth in syngeneic B16 tumor-bearing mice, while the exosomes derived from the non-transfected B16 cells showed no effect on tumor growth, although both exosomes should have similar tumor antigens.
  
  
  CONCLUSIONS
  Exosomes bearing both tumor antigens and the M. tuberculosis antigen (or their epitopes) have a high potential as a candidate for cancer vaccine to overcome the immune escape by tumor cells.
authors.affiliation: Japan Anti-tuberculosis Association, Shin-Yamanote Hospital, 3-6-1 Suwa-cho, Higashimurayama, Tokyo, 189-0021, Japan. drkoyama@vivid.ocn.ne.jp.|Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58 Rinku-oraikita, Izumisano, Osaka, 598-8531, Japan. drkoyama@vivid.ocn.ne.jp.
authors.forename: Yoshiyuki
authors.identifier: http://orcid.org/0000-0002-3102-7535
authors.initials: Y
authors.lastname: Koyama
authors.affiliation: Japan Anti-tuberculosis Association, Shin-Yamanote Hospital, 3-6-1 Suwa-cho, Higashimurayama, Tokyo, 189-0021, Japan.|Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58 Rinku-oraikita, Izumisano, Osaka, 598-8531, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Ito
authors.affiliation: Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58 Rinku-oraikita, Izumisano, Osaka, 598-8531, Japan.
authors.forename: Aya
authors.initials: A
authors.lastname: Hasegawa
authors.affiliation: Japan Anti-tuberculosis Association, Shin-Yamanote Hospital, 3-6-1 Suwa-cho, Higashimurayama, Tokyo, 189-0021, Japan.
authors.forename: Masazumi
authors.initials: M
authors.lastname: Eriguchi
authors.affiliation: Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58 Rinku-oraikita, Izumisano, Osaka, 598-8531, Japan.
authors.forename: Toshio
authors.initials: T
authors.lastname: Inaba
authors.affiliation: Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58 Rinku-oraikita, Izumisano, Osaka, 598-8531, Japan.|Kannai Animal Clinic, 6-3 Yoshida-cho, Naka-ku, Yokohama, Kanagawa, 231-0023, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Ushigusa
authors.affiliation: Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58 Rinku-oraikita, Izumisano, Osaka, 598-8531, Japan.
authors.forename: Kikuya
authors.initials: K
authors.lastname: Sugiura
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D000951:Antigens, Neoplasm / Q000276:immunology; D001426:Bacterial Proteins / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D019496:Cancer Vaccines / Q000008:administration & dosage* / Q000235:genetics / Q000276:immunology; D045744:Cell Line, Tumor; D055354:Exosomes / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D007167:Immunotherapy; D008546:Melanoma, Experimental / Q000188:drug therapy* / Q000235:genetics / Q000276:immunology; D051379:Mice; D009169:Mycobacterium tuberculosis / Q000235:genetics / Q000276:immunology; D014162:Transfection
chemical_list: D000942:Antigens, Bacterial; D000951:Antigens, Neoplasm; D001426:Bacterial Proteins; D019496:Cancer Vaccines; C093276:ESAT-6 protein, Mycobacterium tuberculosis
keywords: Cancer vaccine; Early secretory antigenic target-6 (ESAT-6); Exogenous danger signal; Exosomes; Mycobacterium tuberculosis antigen; Neoantigens; Neoepitopes