Localization of LAK Cells and IL-2-Stimulated Regional Lymph Node Lymphocytes by Regional Arterial Infusion in Renal Tumor-Bearing Rats

Abstract

We describe the results of a traffic assay of the regional arterial administration of either lymphokine-activated killer cells or recombinant interleukin-2-activated regional lymph node lymphocytes in tumor-bearing rats in comparison with the results of systemic or intracardiac administration. The lymphocytes were labeled with 51Cr before infusion. The distribution and localization of these cells were serially evaluated by counting the radioactivity of the removed tissues. Concerning arterial administration, the labeled cells were directly infused into the abdominal aorta just proximal to the left renal artery. In the systemic or intracardiac route, the labeled cells preferentially localized to the lung, spleen and liver 2 h after injection. Radioactivity of the lung decreased thereafter and that of the spleen increased. In contrast, regional arterial administration yielded a remarkable accumulation of radioactivity in the left renal parenchyma 2 and 6 h after injection, similar to other distal organs tested. In the renal tumor model, the percentage radioactivity of the tumor tissue (% injectate recovered/g tissue) obtained at 6 h after injection in the arterial administration group ranged from 0.40 to 1.33, which was significantly higher (p < 0.05) than that in the systemic administration group. However, the radioactivity rapidly decreased from the tumor tissue 18 h after the injection. This study raises the essential issue on the mechanism of tumor destruction by lymphokine-activated killer lymphocytes in adoptive immunotherapy.