Cany J, Avril A, Pichard V, Aubert D, Ferry N, Conchon S. A transgenic mouse with beta-Galactosidase as a fetal liver self-antigen for immunotherapy studies.
J Hepatol 2007;
47:396-403. [PMID:
17462783 DOI:
10.1016/j.jhep.2007.03.018]
[Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2007] [Revised: 03/01/2007] [Accepted: 03/05/2007] [Indexed: 12/04/2022]
Abstract
BACKGROUND/AIMS
To optimise vaccination strategies for immunotherapy in the liver, we have generated a line of transgenic mice expressing beta-Galactosidase downstream of the alpha-fetoprotein promoter (AFP/betaGal).
METHODS
betaGal expression was documented by qRT-PCR, enzyme activity and immunohistochemistry. betaGal-specific CD8+ T-cell activation in mice immunised with various vectors was measured by interferon-gamma ELISpot.
RESULTS
Like AFP, betaGal expression was detected in fetal hepatocytes and disappeared around birth. In adult mice, a CD8+ T-cell response to betaGal was observed after immunisation with betaGal adenovirus or plasmid DNA but not with betaGal protein or after retroviral infection. When betaGal was re-expressed in adult hepatocytes, immunisation with betaGal adenovirus triggered T-cell mediated elimination of betaGal-expressing hepatocytes. However, the response was weaker than in AFP/betaGal animals in which betaGal was only present around birth.
CONCLUSIONS
In AFP/betaGal mice, betaGal is a fetal liver self-antigen. Interestingly, the basal tolerance to betaGal displayed by these animals is increased during liver re-expression of the self-antigen in adulthood. Adenoviral immunisation allows complete elimination of betaGal-expressing hepatocytes in spite of this increased peripheral tolerance. These results highlight the importance of tolerance against self-antigens and validate the AFP/betaGal mice as a good background to test immunotherapy strategies in hepatocarcinogenesis models.
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