Inhibition of early tumor growth requires J alpha 18-positive (natural killer T) cells
Stewart, T.J.; Smyth, M.J.; Fernando, G.J.P.; Frazer, I.H.; Leggatt, G.R.
Cancer Research 63(12): 3058-3060
2003
ISSN/ISBN: 0008-5472 PMID: 12810627 Document Number: 553549
The role of natural killer T (NKT) cells in the immune response to tumor cells has been largely unexplored. As a model of adoptive tumor immunotherapy, cells from the draining lymph nodes of mice immunized with a tumor-specific or irrelevant antigen were transferred to naïve recipients with established tumor. Inhibition of early tumor growth (day 4) required the transfer of both CD8(+) and J alpha 18(+) (NKT) cells from immunized animals without regard to immunogen. In contrast, CD8(+) cells, but not J alpha 18(+) cells, were necessary for the inhibition of late tumor growth (day 8). Thus, the developing tumor changes in sensitivity to NKT-mediated events and the role for NKT cells cannot be replaced by the presence of tumor-specific cells during early tumor growth. This suggests that recruitment/activation of J alpha 18(+) NKT cells is an important consideration during the immune therapy of early stage tumors.