For the assay of the production of Interleukin 2 (IL-2) in human peripheral blood lymphocytes (human PBL), a study was made on the optimal condition for its culture.
1) The optimal condition for the production of IL-2 was considered to be incubation time of 24 hr, number of PBL of 1 x 106 cells/ml, and phytohemagglutinin-M (PHA-M) concentration of 1 — 5%
2) By one way mixed lymphocyte reaction (one way MLR), IL-2 activity similar in level to that by PHA-M stimulation could also be obtained. It was maximal at the 4th day of culture.
3) By PHA-P (0.06%) stimulation, IL-2 could also be produced similar to that by PHAM stimulation but it decreased in the order of Con A, PWM and PPD and hardly any production of IL-2 could be observed by LPS
