ISSN:
1432-0851
Keywords:
Key words Tumor vaccine
;
MCP-1
;
Malignant glioma
;
9L gliosarcoma model
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract Recently, there has been renewed interest in the concept of tumor vaccines using genetically engineered tumor cells expressing a variety of cytokines to increase their immunogenicity. Human MCP-1 (JE) is a potent chemoattractant and activator of monocytes and T lymphocytes and thus a good candidate gene for a tumor vaccine. We therefore evaluated the efficacy of vaccines consisting of irradiated tumor cells transduced with the murine MCP-1 gene in the syngeneic 9L gliosarcoma brain tumor model. 9L cell lines stably expressing murine MCP-1 (9L-JE) and control cell lines expressing neomycin 3′ phosphotransferase (9L-Neo) were generated by infection with a Moloney murine leukemia retroviral vector. Fisher 344 rats were immunized with intradermal injections of 5×105 or 2×106 irradiated (5000 cGy) 9L-JE, 9L-Neo, and wild-type 9L (9L-WT) cells. Two weeks later immunized and non-immunized animals were challenged with varyious doses of intradermal (5×106 – 5×107) or intracerebral (2×104 – 5×105) 9L-WT cells. Intradermal tumors grew in all non-immunized animals. No tumors grew in animals immunized with irradiated 9L-JE or 9L-Neo cells and challenged with inocula of fewer than 5×105 9L-WT cells. With higher inocula up to 107 cells, tumors appeared in all the animals, but subsequently regressed in the immunized animals. Tumors in animals immunized with 9L-JE were always smaller than tumors in the other groups. In addition, only the 9L-JE vaccine protected against tumor inocula of 5×107 cells. Thus vaccination with MCP-1-expressing cells was able to protect animals against at least a 100-fold larger number of challenge tumor cells than vaccination with control cells. In contrast to studies with intradermal tumors, immunization with 9L-JE and 9L-Neo produced only minimal protection against intracerebral tumors. There was no significant difference between the 9L-JE and 9L-Neo vaccines in intracerebral challenge. This study suggests that tumor vaccines expressing cytokine genes such as MCP-1 can increase the antitumor response. However, the protective effect of these vaccines appears to be largely limited to intradermal tumors rather than intracerebral tumors.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01516997
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