抄録
Twenty-nine patients operated on for colon cancer were preoperatively administered lentinan and recombinant interleukin-2 (rIL-2) in order to study the local immunomodulating effect on the tumor itself. The patients were divided into a control group, group A given 2mg of lentinan and 100, 000 JRU of rIL-2, and group B given 2mg of lentinan and 400, 000 JRU of rIL-2. Groups A and B received 8 doses of each agent from 2 weeks before the operation. Resected tumor tissues were subjected to immunostaining with antibodies for MT-1, CD4 or CD8. Greater local infiltration of CD4-positive T lymphocytes (p<0.05 in group B) and CD8-positive lymphocytes (p<0.05 in group B) was observed in groups A and B than in the control group. This infiltration increased along with the dose of rIL-2. When expression of the IL-2R β-chain was assessed after administration of lentinan and rIL-2, expression was even on the T lymphocytes infiltrating the interstitial around the cancers, and it was enhanced in group A and group B (p<0.05) compared with the controls. Both CD4- and CD8-positive cells expressed the IL-2R β-chain. This study indicated that IL-2R expression on lymphocytes was increased by concomitant administration of lentinan and rIL-2. These lymphocytes subsequently infiltrated tumors and mobilized effector cells.
