Induction of antigen-specific CTL and antibody responses in mice by a novel recombinant tandem repeat DNA vaccine targeting at mucin 1 of pancreatic cancer.
OBJECTIVE
Tandem repeat (TR) is the key epitope of mucin 1 (MUC1) for inducing cytotoxic T lymphocytes (CTL) to kill the tumor cells specifically. This study aimed to construct a new recombinant DNA vaccine based on single TR and to investigate the induced immune responses in mice.


METHODS
After the synthesis of a recombinant human TR(rhTR)and the construction of the recombinant plasmid pcDNA3.1-TR/Myc-his (+) A (pTR plasmid), C57BL/6 (H-2(b)) mice were immunized with it (TR group, n = 15). Mice inoculated with the empty vector (EV group, n = 15) and normal saline (NS group, n = 15) were used as vector and blank control, respectively. Cytotoxic assay was carried out to measure the CTL activity. And indirect enzyme-linked immunosorbent assay (ELISA) was used to detect anti-TR-specific antibodies.


RESULTS
TR group resulted in more efficient induction of CTL-specific cytolysis against TR polypeptide than both EV and NS groups (both P < 0.01). Vaccine-immunized mice had a higher equivalent concentration of anti-TR-specific antibodies (2,324 ± 238 μg/ml) than either of EV group (1,896 ± 533 μg/ml, P < 0.01) or NS group (1,736 ± 142 μg/ml, P < 0.01).


CONCLUSIONS
The novel recombinant TR DNA vaccine targeting at MUC1 of pancreatic cancer was constructed successfully, effectively expressing TR polypeptide in the transfected mammalian cells and inducing TR-specific CTL and antibody response.
Department of General Surgery, Zhongshan Hospital, Fudan University, 180 Feng Lin Road, Shanghai 200032, People's Republic of China.
Wen-Chuan
WC
Wu
Da-Yong
DY
Jin
Wen-Hui
WH
Lou
Dan-Song
DS
Wang
Xin-Yu
XY
Qin
D000818:Animals; D000906:Antibodies / Q000097:blood / Q000276:immunology; D000917:Antibody Formation / Q000276:immunology; D000941:Antigens / Q000276:immunology*; D001483:Base Sequence; D019556:COS Cells; D002522:Chlorocebus aethiops; D016207:Cytokines / Q000097:blood / Q000276:immunology; D003602:Cytotoxicity, Immunologic / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007114:Immunization; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D018396:Mucin-1 / Q000235:genetics / Q000276:immunology*; D010190:Pancreatic Neoplasms / Q000235:genetics / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D020080:Tandem Repeat Sequences / Q000235:genetics / Q000276:immunology; D013997:Time Factors; D019444:Vaccines, DNA / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*
D000906:Antibodies; D000941:Antigens; D016207:Cytokines; D018396:Mucin-1; D019444:Vaccines, DNA