title: [Immunogenicity of the recombinant plasmid of Leishmania donovani amastigote gene].
abstract: OBJECTIVE
  To investigate the immunogenicity of recombinant plasmid pcDNA3.1-amastigote with Leishmania donovani amastigote gene.
  
  
  METHODS
  Eighteen female BALB/c mice were randomly divided into experimental group and control group. Mice in experimental group and control group were intramuscularly injected with 50 microg recombinant plasmid pcDNA3.1-amastigote and blank plasmid vector pcDNA3.1(+), respectively, and then received equivalent dose of plamid after 2 weeks. On days 7, 14, and 21 after the second immunization, serum samples were collected from 3 mice each group. The mice were then sacrificed, spleens were removed and splenocytes were collected. Serum antibody level was determined by indirect ELISA. Splenocyte proliferation responses and cytotoxicity of spleen-derived lymphocytes were analyzed by MTT colorimetry after stimulation with ConA. Level of IFN-gamma, IL-2 and IL-4 in the splenocyte culture supernatants was determined by double antibody sandwich ELISA.
  
  
  RESULTS
  On days 7, 14, and 21 after the second immunization, specific IgG antibody (more than 1:640) was found in experimental group, but not in the control (P < 0.01); stimulation index (SI) of spleen cells in experimental group (428 +/- 0.51, 5.01-0.60, and 4.39 +/- 0.50) was higher than that of control group (P < 0.01); the level of IFN-gamma [(42.06 +/- 4.26), (66.02 +/- 6.02), and (58.29 +/- 3.75) pg/ml] and IL-2 [(38.21 +/- 5.11), (64.79 +/- 8.67), and (52.69 +/- 7.15) pg/ml] in splenocyte culture supernatants of experimental group was higher than that of control group (P < 0.01); IL-4 was not found in the two groups; cytotoxicity of spleen-derived lymphocytes in experimental group [(42.20 +/- 5.96)%, (63.66 +/- 5.44)%, and (52.24 +/- 4.56)%] was stronger than that of control (P < 0.01).
  
  
  CONCLUSIONS
  The recombinant plasmid pcDNA3.1-amastigote can induce specific humoral and Th1 type cellular immune responses in mice.
authors.affiliation: Departmnent of Parasitology, Guiyang Medical College, Guiyang 550004, China.
authors.forename: Jin-fu
authors.initials: JF
authors.lastname: Li
authors.forename: Jian-ping
authors.initials: JP
authors.lastname: Chen
authors.forename: Yu
authors.initials: Y
authors.lastname: Tian
authors.forename: Zhi-wei
authors.initials: ZW
authors.lastname: Yang
authors.forename: Ying
authors.initials: Y
authors.lastname: Ma
authors.forename: Xiao-su
authors.initials: XS
authors.lastname: Hu
mesh_terms: D000818:Animals; D005260:Female; D005822:Genetic Vectors; D007111:Immunity, Cellular; D056724:Immunity, Humoral; D007371:Interferon-gamma / Q000276:immunology; D007376:Interleukin-2 / Q000276:immunology; D015847:Interleukin-4 / Q000276:immunology; D007893:Leishmania donovani / Q000235:genetics / Q000276:immunology*; D054332:Leishmaniasis Vaccines / Q000276:immunology*; D008214:Lymphocytes / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D010957:Plasmids; D015800:Protozoan Proteins / Q000235:genetics / Q000276:immunology*; D018417:Th1 Cells / Q000276:immunology; D019444:Vaccines, DNA / Q000276:immunology*
chemical_list: D007376:Interleukin-2; D054332:Leishmaniasis Vaccines; D015800:Protozoan Proteins; D019444:Vaccines, DNA; D015847:Interleukin-4; D007371:Interferon-gamma