A new method for rapid cytotoxic T-lymphocyte induction using a multiple cytokine cocktail

Immunotherapy using cytotoxic T-lymphocytes (CTLs) still has limited success. An increase in the frequency of CTL administration is one method to improve immunotherapy using CTLs. The conventional method (C-method) that generates CTLs after the induction of dendritic cells requires a long time period. If CTLs can be more rapidly and simply induced, the frequency of immunotherapy could be increased and unexpected contamination could be avoided. In this study, in order to more rapidly induce functional CTLs, we investigated a new method (N-method) that uses a cytokine cocktail, including interleukin (IL)-2, IL- 4, granulocyte macrophage colony-stimulating factor, tumour necrosis factor-α and interferon-α, together with a tumour lysate. CTLs induced by the N-method had equivalent functions, such as proliferation, surface antigen expression and cytotoxicity, compared with those induced by the C-method. These results suggest that the N-method can substitute the C-method in order to improve the effect of immunotherapy using CTLs.