Biodistribution of LAK cells in mice bearing tumor

For the improvement of IL-2 and LAK (lymphokine activated killer cells) therapy in tumor, it is desired that an enough amount of adoptively transferred LAK cells migrate to and localize in tumor tissue. We observed the changes of the biodistribution of 51Cr labeled AK cells when tumor-bearing mice were exposed to different doses of local γ-ray irradiation on tumor. Our experiment showed that: (1) 51Cr labeled LAK cells distributed mainly into liver and spleen 24 h after i.v. administration and only low level radioactivity of 51Cr labeled LAK cells were detected from tumor lungs and blood in control group. It may be one of the reasons for the inability of AK cells to eradicate tumor metastases completely in vivo; (2) The mean percentage of total injected activity localizing per gram tumor was 1.04 +- 0.79 in the 10 Gy irradiated group and 0.68 +- 0.22 in the control group, the mean of the tumor to spleen distribution ratio of 10 Gy irradiated group was 3.7 times that for control group, indicating that 10 Gy γ-ray irradiation may enhances the infiltration of LAK cells into tumor tissue