PURPOSE: High-efficiency production of lymphokine is effected by cultivating human T-lymphocytes which have been established by infection with human T- lymphocyte leukemia virus.

CONSTITUTION: Human adult T-lymphocyte leukema virus, which is irradiated with X-rays of 2,000W30,000 RAd to lose completely its peroliferation activity and the peripheral lumphocytes of healthy adults are inocultated to the RPMI- 164 culture medium containing 1W50% of calf serum and 10W50% of interleukin- 2 and cultured in an incubator filled with carbon dioxide at 20W40°C for 10hr to 10 days to produce and accumulate at least one of interferon and macrophage differentiation factor, which is then separated from the cells and viruses.