title: [Preventive and therapeutic effect of genetic vaccine based on recombinant alpha virus against mouse mastocytoma P815].
abstract: OBJECTIVE
  To explore the immunological effect of genetic vaccine based on alpha-virus and to seek out better forms of gene vaccines.
  
  
  METHODS
  Expression plasmid P1A/pSMART2a and packaging plasmid helper were cotransfected into mammalian 293 cells by calcium phosphate precipitation method and high level of recombinant alpha-virus P1A/SFV was prepared. Following identification of rSFV and its expression, BALB/c mice were inoculated with rSFV, and the production of antigen-specific antibody and the cytotoxic effect of CTLs were determined. In the preventive and therapeutic experiments, the percents of tumor-free and of survival mice immunized with rSFV were observed.
  
  
  RESULTS
  The recombinant SFV could express correctly in cultured cells. After being inoculated into the mice, rSFV could prime stronger CTL response than that in control mice. When the ratio of E/T cells was 100:1, the (51)Cr release rate reached 75%. No antibody could be detected in mice from all groups. The immunological effect of P1A/SFV among all groups was the best in both preventive and therapeutic experiment within experimental deadline. On 60th day in preventive experiment, the percent of tumor-free animal in P1A/SFV group reached 60%, whereas that was only 20% in P1A/pCI-neogroup. On 60th day in therapeutic experiment, survival rate of mice in P1A/SFV group reached 50%, but only 10% mice could survive in all control groups.
  
  
  CONCLUSIONS
  Compared with common gene vaccines, the genetic vaccine based on recombinant SFV has the best immunological effect, which provides some new strategies for clinical genetic therapy of tumors.
authors.affiliation: Institute of Immunology, Third Military Medical University, Chongqing 400038, China. nibingxi@hotmail.com
authors.forename: Bing
authors.initials: B
authors.lastname: Ni
authors.forename: Ri-gao
authors.initials: RG
authors.lastname: Yang
authors.forename: Yan-qiu
authors.initials: YQ
authors.lastname: Li
authors.forename: Yu-zhang
authors.initials: YZ
authors.lastname: Wu
mesh_terms: D000818:Animals; D000951:Antigens, Neoplasm / Q000235:genetics* / Q000276:immunology; D019496:Cancer Vaccines / Q000627:therapeutic use*; D005260:Female; D015316:Genetic Therapy; D034801:Mastocytoma / Q000517:prevention & control* / Q000628:therapy; D051379:Mice; D008807:Mice, Inbred BALB C; D008811:Mice, Inbred DBA; D012672:Semliki forest virus / Q000235:genetics*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D014614:Vaccines, Synthetic / Q000627:therapeutic use*
chemical_list: D000951:Antigens, Neoplasm; D019496:Cancer Vaccines; D014614:Vaccines, Synthetic; C076546:tumor rejection antigen P815A, mouse