Induction of lymphokine activated killer cells in serum-free medium

Lymphokine activated killer (LAK) cells may play a role in immunosurveillance against spontaneous neoplasms. To date, LAK cells have been grown in medium supplemented with human serum (HS). Formulation of a defined medium that supports LAK cell generation would be useful to delineate the mechanisms that regulate LAK cell induction. When compared to HS medium, optimal induction of LAK cells required medium containing transferrin, insulin, bovine serum albumin, fatty acids (linoleic, oleic, palmitic), pyruvate and indomethacin. In addition, when 5% autologous monocytes were added to PBMC cultured in serum-free medium without indomethacin, marked suppression of LAK cell induction occurred. Addition of indomethacin abrogated suppression and resulted in enhanced cytotoxicity compared to non-adherent PBMC cultured in HS medium.