Successful transplantation of a human leukemia cell line into nude mice: conditions optimizing graft acceptance

Conditions were determined for successful subcutaneous tumor development of MOLT-4 human T-cell leukemia cells in BALB/c nude (nu/nu) female mice. MOLT-4 cells injected alone at one site resulted in tumors in none of 21 mice, whereas MOLT-4 cells injected with X-irradiated human fibrosarcoma cells (HT-1080) at another site resulted in tumors in 5 of 21 mice. When X-irradiated three times with 200 rad over a 3-week period and then inoculated with MOLT-4 cells and X-irradiated HT-1080 cells, 19 of 25 mice developed tumors, which indicated that a combination of X-irradiation of the recipients and inoculation of an admixture of the leukemia cells with X-irradiated fibrosarcoma cells markedly increases tumor incidence. The cells growing in the tumors had the characteristics of MOLT-4, as assessed by marker studies and histology.