title: Antitumor activity of mixed heat shock protein/peptide vaccine and cyclophosphamide plus interleukin-12 in mice sarcoma.
abstract: BACKGROUND
  The immune factors heat shock protein (HSP)/peptides (HSP/Ps) can induce both adaptive and innate immune responses. Treatment with HSP/Ps in cancer cell-bearing mice and cancer patients revealed antitumor immune activity. We aimed to develop immunotherapy strategies by vaccination with a mixture of HSP/Ps (mHSP/Ps, HSP60, HSP70, Gp96 and HSP110) enhanced with cyclophosphamide (CY) and interleukin-12 (IL-12).
  
  
  METHODS
  We extracted mHSP/Ps from the mouse sarcoma cell line S180 using chromatography. The identity of proteins in this mHSP/Ps was assayed using SDS-PAGE and Western blot analysis with antibodies specific to various HSPs. BALB/C mice bearing S180 cells were vaccinated with mHSP/Ps ×3, then were injected intraperitoneally with low-dose CY and subcutaneously with IL-12, 100 μg/day, ×5. After vaccination, T lymphocytes in the peripheral blood were analyzed using FACScan and Cytotoxicity (CTL) was analyzed using lactate dehydrogenase assay. ELISPOT assay was used to evaluate interferon γ (IFN-γ), and immune cell infiltration in tumors was examined in the sections of tumor specimen.
  
  
  RESULTS
  In mice vaccinated with enhanced vaccine (mHSP/Ps and CY plus IL-12), 80% showed tumor regression and long-term survival, and tumor growth inhibition rate was 82.3% (30 days), all controls died within 40 days. After vaccination, lymphocytes and polymorphonuclear leukocytes infiltrated into the tumors of treated animals, but no leukocytes infiltrated into the tumors of control mice. The proportions of natural killer cells, CD8+, and interferon-γ-secreting cells were all increased in the immune group, and tumor-specific cytotoxic T lymphocyte activity was increased.
  
  
  CONCLUSIONS
  In this mice tumor model, vaccination with mHSP/Ps combined with low-dose CY plus IL-12 induced an immunologic response and a marked antitumor response to autologous tumors. The regimen may be a promising therapeutic agent against tumors.
authors.affiliation: Institute of Orthopedic Research, General Hospital of the People's Liberation Army, Beijing 100853, China.
authors.forename: Quan-Yi
authors.initials: QY
authors.lastname: Guo
authors.forename: Mei
authors.initials: M
authors.lastname: Yuan
authors.forename: Jiang
authors.initials: J
authors.lastname: Peng
authors.forename: Xue-Mei
authors.initials: XM
authors.lastname: Cui
authors.forename: Ge
authors.initials: G
authors.lastname: Song
authors.forename: Xiang
authors.initials: X
authors.lastname: Sui
authors.forename: Shi-Bi
authors.initials: SB
authors.lastname: Lu
mesh_terms: D000818:Animals; D024221:Antineoplastic Protocols; D019496:Cancer Vaccines / Q000627:therapeutic use*; D045744:Cell Line, Tumor; D003520:Cyclophosphamide / Q000627:therapeutic use*; D005260:Female; D006360:Heat-Shock Proteins / Q000276:immunology / Q000627:therapeutic use*; D007167:Immunotherapy / Q000379:methods*; D018664:Interleukin-12 / Q000627:therapeutic use*; D051379:Mice; D008807:Mice, Inbred BALB C; D012513:Sarcoma, Experimental / Q000276:immunology / Q000628:therapy*; D013601:T-Lymphocytes / Q000276:immunology; D022223:Vaccines, Subunit / Q000627:therapeutic use
chemical_list: D019496:Cancer Vaccines; D006360:Heat-Shock Proteins; D022223:Vaccines, Subunit; D018664:Interleukin-12; D003520:Cyclophosphamide