ABSTRACT
To investigate the antitumor immune responses induced by MAGE-3 DNA vaccine, the recombinant mammalian expression plasmid pcDNA3.1/MAGE-3 was constructed by ligating MAGE-3 gene, which was amplified by RT-PCR, and the pcD-NA3.1 + vector. The recombinant plasmids were transfected into B16 cells by liposome, the expression of MAGE-3 was checked by RT-PCR, immunocytochemistry and Western blot. Then, 100 ug recombinant plasmids were injected intramuscularly per C57BL/6 mouse on 0, 10 and 20 days, with pcDNA3.1 + plasmid and PBS as controls. Splenocytes CTLs, the level of antibodies against MAGE-3 the changes of the T lymphocyte subsets and the levels of cytokines were checked after 3 times immunization. As a result, the mice immunized with pcDNA3.1/MAGE-3 plasmid can produce MAGE-3 specific immune response. The CTLs kill activities against B16/MAGE-3 cells was 51.08 +/- 7.41%, and had significant difference (P < 0.01) compared with that of pcDNA3.1 + group (8.44 +/- 1.89%) and PBS group (5.76 +/- 1.75%). The titre of antibody against MAGE-3 was 1:15, while controls were negtive. The number of CD4 + CD8 + and the levels of IFN-gamma IL-2 increased significantly after immunization with pcDNA3.1/MAGE-3 plasmid as compared with those of control groups (P < 0.01). It is concluded that the pcDNA3.1-MAGE-3 DNA vaccine are able to induce both cellular and humoral immune responses in vivo.
Subject(s)
Animals , Female , Mice , Antibodies, Neoplasm , Blood , Antigens, Neoplasm , Genetics , Allergy and Immunology , Cancer Vaccines , Allergy and Immunology , Melanoma, Experimental , Mice, Inbred C57BL , Neoplasm Proteins , Genetics , Allergy and Immunology , Recombinant Fusion Proteins , Genetics , Allergy and Immunology , T-Lymphocyte Subsets , Allergy and Immunology , Vaccination , Vaccines, DNA , Genetics , Allergy and ImmunologyABSTRACT
To express the GST-MAGE-3 protein in E. coli, and investigate the antitumor immune responses induced by Dendritic cells (DCs) pulsed with GST-MAGE-3 protein, the recombinant expression plasmid pGEX-MAGE-3 was constructed by ligating MAGE-3 gene, which was amplified by RT-PCR and confirmed by sequencing, and the pGEX-4T-2 vector. The recombinant plasmid was transformed into BL-21 E. coli. The expression of GST-MAGE-3 was induced with IPTG. The GST-MAGE-3 protein expressed as high as 32% of the total cellular protein. After purification with Glutathione Sepharose 4B, the purity of the protein was more than 90%, and 3mg GST-MAGE-3 was obtained from 100 mL BL-21 lysate. Dendritic cells from gastric carcinoma patients were pulsed with GST-MAGE-3 protein, and these DCs were used to stimulate the autologous T. lymphocytes. After 7 days, the T. lymphocytes cocultured with DCs pulsed with GST-MAGE-3 antigen exhibited specific cytotoxicity against MAGE-3 positive SGC-7901 cells. It is concluded that the GST-MAGE-3 protein are able to present antigen to T. lymphocytes, activate antigen-specific CTLs and induce special antitumor immune responses in vitro. Our results lay the groundwork for further research of the MAGE-3 vaccine.