Li H, Ou X, Xiong J. Modified HPV16 E7/HSP70 DNA vaccine with high safety and enhanced cellular immunity represses murine lung metastatic tumors with downregulated expression of MHC class I molecules.
Gynecol Oncol 2007;
104:564-71. [PMID:
17081598 DOI:
10.1016/j.ygyno.2006.09.027]
[Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2006] [Revised: 09/13/2006] [Accepted: 09/28/2006] [Indexed: 11/24/2022]
Abstract
OBJECTIVE
To explore whether the modified E7-HSP70, which has been introduced mutations in two zinc-binding motifs of E7, will eliminate its transformation potential and enhance the immunogenicity of fusion protein and repress E7 containing tumors with a low level of MHC-I molecules to lung metastatic in murine model.
METHODS
In this study, we examined the transforming properties of mutant E7 oncoprotein by the soft agar colony-formation assays, explored the immunogenicity of modified E7-HSP70 gene by various cellular and humor immune responses and evaluated the effect of treating lung metastatic tumor with a low expressing MHC-I molecules by tumor challenge assay and therapeutic experiment.
RESULTS
The mutant E7 oncoprotein has completely lost its transforming properties as measured in the soft agar colony-formation assays. Modified E7-HSP70 gene inducted stronger E7-specific cellular immune response than that induced by unmodified E7-HSP70. More importantly, the new construct significantly reduced the number of B16-HPV16E7 lung metastases.
CONCLUSION
The modified E7-HSP70 gene may be as a powerful and safe DNA vaccine in controlling the hematogenous spread of HPV16E7-associated tumors with low expression of MHC-I molecules. In addition, the B16-HPV16E7 lung metastasis model can be used to test the efficacy of various E7-specific vaccines and immunotherapeutic strategies in settings more relevant to clinical requirements.
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