| abstract |
A method of producing NK lymphocytes in vitro, comprising the steps of: (i) isolating leukocytes from peripheral blood and NK lymphocytes from human peripheral blood; (ii) stimulate NK lymphocytes by carrying out a stationary culture for 2-15 days in a medium containing anti-CD3 antibody, cytokine and feeder cells, to cause cell-cell contact; (iii) after completion of the stationary culture of step (ii), re-stimulate the cells by the addition of cytokine, anti-CD3 antibody and feeder cells, and carry out a stationary culture to cause cell-cell contact; (iv) after the completion of the stationary culture, add to the cells a medium containing a cytokine necessary for stationary or suspension culture, and carry out a stationary or suspension culture while maintaining the cell concentration and concentration of cytokine at constant levels. |