Modulation of cell surface markers on NK-like T lymphocytes by using IL-2, IL-7 or IL-12 in vitro stimulation.

Cytotoxicity and proliferation of NK-like T (CIK) cells are dependent on the continuous presence of exogenous cytokines, but it is not known which cytokine is optimal. Here, we compared the effect of exogenous interleukin 2 (IL-2), interleukin 7 (IL-7) or interleukin 12 (IL-12) on the generation of CIK cells in addition to IL-1, interferon-gamma and anti-CD3 antibodies. Cell surface markers important for cytotoxic activity and adhesion were defined and cytokines leading to their optimal expression were determined. The most important findings were: (a) IL-12 generates the most CD3/CD56-double-positive CIK cells, (b) the expression of LFA-1/CD11a which is important for cytotoxic activity is highest with IL-7, and (c) IL-7 also generates the most CD28-positive cells which may enhance T cell receptor co-stimulation. In summary, essential differences concerning antigen expression were found when generating CIK cells using IL-7 or IL-12 instead of IL-2. In particular, IL-12 may be of interest due to the high expansion of CD56 positive cells in CIK cell cultures and the important role of these cells in mediating cytotoxicity towards malignant tissues. Copyright 2000 Academic Press.