[A luminescent assay for natural cytotoxicity using K562 cells transfected with the plasmid producing alkaline phosphatase].
A novel non-radioactive assay for natural cytotoxicity is described. A new target cell line was established by the transfection of K562 cells with a plasmid encoding DNA for secretion type of placental alkaline phosphatase(ALP). The assay was based on the kinetic determination of heat-stable ALP in the co-culture of the target cells with effector sample from human peripheral blood. The inactivated effector sample for the control prepared by irradiation(50Gy X-ray) or heat treatment(56 degrees C, 20 min), however, showed an enhancement effect on the ALP production in the target cells. This effect was depending on the concentration of monocyte component(adherent cells on plastic dish) by unknown reason, and was not reduced by the treatment for NK inactivation. Cytotoxic activity was therefore determined by the percent decrease in the ALP productivity compared to that in the control. The correlation coefficient between cytotoxicity values by this ALP synthesis assay and those by 51Cr release assay was 0.93. This cytotoxicity test is simple and unique in terms of estimation for protein synthesis affected in target tumor cells, although the mechanism of the monocyte(or macrophage) effect remained to be elucidated.
Kasatori
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Department of Laboratory Medicine, Toho University School of Medicine, Tokyo.
D000469:Alkaline Phosphatase / Q000096:biosynthesis*; D002460:Cell Line; D003602:Cytotoxicity, Immunologic; D006801:Humans; D020014:K562 Cells; D007694:Killer Cells, Natural / Q000276:immunology*; D008163:Luminescent Measurements; D010957:Plasmids; D014162:Transfection
D000469:Alkaline Phosphatase