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Vaccine
therapy for murine glioma using tumor cells genetically modified to express b7.1
Morioka J, Kajiwara K, Yoshikawa K, Ideguchi M, Uchida T, Suzuki M
Department of Neurosurgery, Yamaguchi University School of
Medicine, Yamaguchi, Japan.
Objective. In a syngeneic mouse brain tumor model, we tested the
hypothesis that vaccination with tumor cells genetically modified to express
B7.1 molecules induces tumor-specific T cells and immunological antitumor
effects.
Methods.
Malignant glioma cells
(RSV-MG) derived from a C3H/He mouse induced by Schmidt-Ruppin Rous sarcoma
virus (RSV) were infected with an adenovirus encoding the B7.1 gene
(AdB7).
To investigate the effects of B7.1 expression on the tumorigenicity of RSV-MG
cells, infected cells were implanted subcutaneously into C3H/He mice.
The C3H/He mice were vaccinated with AdB7 transfectants injected subcutaneously
and 2 weeks later were challenged intracerebrally with wild-type RSV-MG cells to
determine whether or not the expression of B7.1 would enhance the immunogenicity
of RSV-MG cells.
Results.
Immunocytochemistry confirmed the expression of B7.1 and major
histocompatibility complex Class I antigen on the infected cells.
The growth of subcutaneous tumors was markedly retarded in the AdB7 group,
whereas tumors had formed and progressively increased in size in the other
control groups.
In the vaccine experiments, the mice immunized with AdB7 transfectants survived
longer than did the mice of the other groups, and a significant difference in
survival times was noted.
Immunocytochemistry revealed that brain tumors in mice previously vaccinated
with AdB7 infectants had been infiltrated by a larger number of CD3(+)
lymphocytes and that these CD3(+) lymphocytes contained not only CD4(+) and
CD8(+) T cells but also CD25(+)-activated T cells.
In addition, a cytotoxicity assay confirmed that vaccination with the AdB7
transfectants induced tumor-specific cytotoxicity.
Conclusion.
These results demonstrate the therapeutic potential of vaccination with tumor
cells expressing B7.1 for the treatment of malignant glioma.
PMID: 14683556 [PubMed - in process]
Source: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14683556&dopt=Abstract
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