Enhanced immunogenicity and antitumour effects with heterologous prime-boost regime using vaccines based on MG7-Ag mimotope of gastric cancer.
MG7-Ag, gastric cancer-associated antigen, has been shown to be immunogenic and has been used as marker molecule for prognosis. In a previous study, we developed an oral DNA vaccine based on MG7-Ag mimotope. However, we failed to detect cellular immune response using the oral MG7-Ag mimotope DNA vaccine. To induce significant T cell response, we developed a recombinant adenovirus vaccine based on MG7-Ag mimotope and evaluated the efficacy and protective effects of heterologous prime-boost immunization protocol with an oral DNA vaccine previously developed. We found that both vaccines were able to elicit a significant humoral response against MG7-Ag, while the highest serum titre MG7 antibody was detected in mice immunized with the heterologous prime-boost immunization protocol. Enzyme-linked immunospot (ELISPOT) assay demonstrated that the heterologous prime-boost immunization strategy was more efficient in inducing T cell response than the homologous prime-boost strategy. In the tumour challenge assay, 2 of 5 mice immunized with the heterologous prime-boost protocol were tumour free, while none of the mice in homologous prime-boost groups or control groups was tumour free. Those tumour-bearing mice in the heterologous prime-boost regime had smaller tumour masses than their counterparts in the homologous prime-boost groups or control groups. Therefore, our study suggests that vaccines against MG7-Ag induce significant immune response against gastric cancer, and that the heterologous prime-boost protocol using different types of vaccines could achieve better protective effect than the homologous prime-boost protocol.
Lin
T
T
State Key Laboratory of Cancer Biology, Institute of Digestive Diseases, Xijing Hospital, Fourth Military Medical University, 15 Changle West Road, Xi'an 710032, China.
Liang
S
S
Meng
F
F
Han
Q
Q
Guo
C
C
Sun
L
L
Chen
Y
Y
Liu
Z
Z
Yu
Z
Z
Xie
H
H
Ding
J
J
Fan
D
D
D000256:Adenoviridae / Q000276:immunology; D000284:Administration, Oral; D000818:Animals; D000912:Antibodies, Neoplasm / Q000276:immunology; D000917:Antibody Formation / Q000276:immunology; D000951:Antigens, Neoplasm / Q000276:immunology*; D019496:Cancer Vaccines / Q000008:administration & dosage / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D007111:Immunity, Cellular / Q000276:immunology; D007371:Interferon-gamma / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D013274:Stomach Neoplasms / Q000276:immunology* / Q000517:prevention & control; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D019444:Vaccines, DNA / Q000008:administration & dosage / Q000276:immunology*; D014614:Vaccines, Synthetic / Q000276:immunology; D014765:Viral Vaccines / Q000008:administration & dosage / Q000276:immunology*
D000912:Antibodies, Neoplasm; D000951:Antigens, Neoplasm; D019496:Cancer Vaccines; C508753:MG7 antigen, human; D019444:Vaccines, DNA; D014614:Vaccines, Synthetic; D014765:Viral Vaccines; D007371:Interferon-gamma