Fusion gene pEGFP-C3-B7.2-hTERT induces immune response in mice and restrains transplanted hepatoma / 中国肿瘤生物治疗杂志

ABSTRACT

Objective:To construct a fusion DNA vaccine pEGFP-C3-B7.2-hTERT and to observe the capability of pEGFP-C3-B7.2-hTERT DNA vaccine to induce specific anti-tumor immune responses and to inhibit growth of the hepatoma transplanted from H22 cells. Methods: The B7.2 and hTERT cDNA (amplified by RT-PCR), together with pEGFP-C3 as the vector were used to construct fusion gene plasmid pEGFP-C3-B7.2-hTERT, which was then used to vaccinated C57BL/6 mice for 3 times at a 7 d interval. Animals vaccinated with pEGFP-C3-B7.2, pEGFP-C3-hTERT, pEGFP-C3 and PBS were taken as controls. Splenocytes CTLs of immunized mice, the levels of IL-2, IFN-? in the culture supernatant, the levels of antibodies against hTERT, and the changes of the T lymphocyte subsets in the peripheral blood were all examined. The mice harboring hepatocarcinoma H22 cells were challenged with pEGFP-C3-B7.2-hTERT and the tumor forming time and the survival periods of mice were observed. Results: Agarose gel electrophoresis, nuclease digestion and sequencing confirmed the successful construction of pEGFP-C3-B7.2-hTERT. The CTLs activity of splenocytes from the mice immunized with pEGFP-C3-B7.2-hTERT fusion gene was significantly higher than those of the other groups (P