Dendritic Cell Vaccine Quells GI Tumors In Mice

NEW YORK (Reuters Health) - Immunization with dendritic cells loaded with syngeneic tumor cells curbs tumor development in mutant mice predisposed to adenomatous polyps of the gastrointestinal tract, according to Japanese and US researchers.

In the May issue of the Journal of Clinical Investigation, Dr. Toshio Iinuma of Jikei University School of Medicine, Tokyo and colleagues note that the ability of dendritic cells loaded with tumor-associated antigens to prime naive T cells, and thus recognize and kill tumor cells has been shown in various animal models.

To evaluate this approach in a colon cancer model, the researchers injected dendritic cells loaded with T cells (DC/Ts) with and without IL-12 into such mutant mice.

Use of DC/Ts alone reduced the development of gastrointestinal tumors. Co-administration of IL-12 further enhanced this effect. In fact, certain mice given both agents had fewer tumors at 10 weeks of age than did untreated mice at 6 weeks. However, no effect was seen when IL-12 was used on its own.

In vitro studies showed that DC/Ts with IL-12 or alone killed tumor cells in vitro, suggesting that "the antibody directed against tumor T cells was itself cytotoxic," the investigators report.

Overall, the researchers conclude that vaccination prevents tumor development "through adenomatous polyposis coli gene mutation and that its preventive effects are mediated by humoral antitumor immunity."

Moreover, they suggest that such an approach might be useful in preventing tumor recurrence following surgical resection in patients with colorectal cancer.

Source: J Clin Invest 2004;113:1307-1316. [ Google search on this article ]

MeSH Headings: Animal Diseases : Disease Models, Animal : Recombinant Proteins : Vaccines, Synthetic : Cancer Vaccines : Diseases