Long-term culture of LAK cells: expansion and activation signals.

Long-term culture of cells in rIL2-containing medium increases LAK activity on a per cell basis and produces an average 30-100-fold expansion over 14-21 days. The stimulation of PBL with anti-CD3 results in a 300-1000-fold increase in cell number while maintaining LAK activity. Cells stimulated with anti-CD3 and cultured in rIL2 for 12 days) can be further stimulated with beta IL1, or beta IFN, producing a further increase in LAK activity. These findings have allowed us to begin understanding the role of different signals in the activation of cells with LAK activity and together with biotechnological advances will allow for the culture of large numbers of cells for experimental and therapeutic purposes.