In vivo immunogenicity of osteosarcoma cells that express B7-1a, an alternatively spliced form of B7-1
Nagamori, M.; Kawaguchi, S.; Murakami, M.; Wada, T.; Inobe, M.; Ishii, S.; Uede, T.
Anticancer Research 22(4): 2009-2013
2002
ISSN/ISBN: 0250-7005 PMID: 12174878 Document Number: 543470
Background: B7 family members play a central costimulatory role in T cell activation. We have previously identified B7-1a, an alternatively spliced form of B7-1. The function of B7-1a in induction of anti-tumor immunity remains uncertain. Materials and Methods: The cDNAs of murine B7-1, B7-1a and B7-2 were introduced into a murine osteosarcoma cell line, LM8. The ability of B7 transfectants to elicit in vivo anti-tumor immunity was comparatively analyzed with respect to tumorigenecity, pulmonary metastasis and survival time. Results: LM8 cells expressing B7-1, B7-1a, or B7-2 all elicited immunological responses in immunocompetent C3H/He mice. Notably, the anti-tumor effects were most obvious in mice inoculated with B7-1a-transfected LM8 cells. Such a difference among B7-transfectants became indistinguishable in immunodeficient nude mice. Conclusion: These findings indicate that B7-1a serves as a more efficacious costimulatory molecule than B7-1 or B7-2 in the induction and maintenance of anti-tumor immune responses against a poorly immunogenic osteosarcoma cell line.