Peripheral blood lymphocytes of normal individuals can be activated by culture with recombinant Interleukin-2 (donated by Genetic Engineering Center, KAIST, Seoul, Korea) leading to expression of cytotoxic activity toward on colorectal carcinoma cell line SNU-05.
After 4 days incubation, the LAK cells were removed by 4 times washing and the number of live target cells in the microtest plates were counted by the tetazolium-based colorimetric (MITT) assay and the survival rate of the target cells was calculated against the control in which the target cells were incubated without Interleukin-2 and effector cells.
During 5 days culture, the recombinant KAIST Interleukin-2 induced the potent LAK cells at the concentration of 0.1 U/ml. After 4 days incubation, almost all target cells (SNU-05) were killed by the LAK cells of 5 days culture when the Effector:Target ratio were 10 : 1 and 5 : 1.
SNU-05 represented high adhesiveness to the culture flask and microtest plate bottom, so it can be used for the tetazolium-based colorimetric (MTT) assay.
Tetrazolium-based colorimetric (MTT) assay shows good correlation between spectrophotometric absorbance and cell number, and it is long-term assay over other cytotoxicity test methods, so semiautomated MTT assay offers a valid, rapid, and simple method to assess cytotoxicity of LAK cells.
|