This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Liu, C.-M. Articles by Wheelock, E. F. Search for Related Content PubMed PubMed Citation Articles by Liu, C.-M. Articles by Wheelock, E. F.

Maintenance and Cure of the L5178Y Murine Tumor-dormant State by Interleukin 2: In Vivo and in Vitro Effects¹

Department of Pathology and Laboratory Medicine, Hahnemann University [C-M. L., Y. S., L. C., T. O., E. F. W], and the Department of Microbiology, Thomas Jefferson University [C. E. C.], Philadelphia, Pennsylvania

We studied the antitumor effects of recombinant human interleukin 2 (HuIL-2) in DBA/2 mice which harbor L5178Y lymphoma cells in a tumor-dormant state in the peritoneal cavity and in peritoneal cell (PC) cultures prepared from such mice. Intraperitoneal injection of 10,000 to 100,000 units of HuIL-2/day for 10 days eliminated tumor cells from 30–45% of the mice, whereas no mice became tumor-free in the phosphate-buffered saline-treated control group. In vitro, as little as 10 units/well HuIL-2 stimulated antitumor cytotoxic activity in PC from tumor-dormant mice, whereas HuIL-2 in concentrations up to 1,000 units/well HuIL-2 failed to stimulate cytotoxic activity in PC from normal mice. HuIL-2 directly stimulated antitumor cytotoxic activity in nonadherent but not in adherent PC cultures from tumor-dormant mice; however, treatment of whole PC from tumor-dormant mice with HuIL-2 resulted in the development of antitumor cytotoxic activity in the adherent PC population which were derived from such cultures. This suggests that the HuIL-2-treated nonadherent PC contributed to the cytotoxic activation of the adherent PC. Flow cytometric analysis of the PC from tumordormant mice revealed a polyclonal expansion of T-lymphocytes. Lyt-1⁺, Lyt-2⁺, and L3T4⁺ lymphocytes were all required for HuIL-2 to induce antitumor cytotoxic activity.

¹ Supported by PHS Grants CA32577 and CA37438, awarded by the National Cancer Institute, HHHS, and by a grant from Hoffmann La Roche.

² Present address: Beckman Instruments, 200 S. Kraemer Blvd., Brea, CA 92621.

³ Present address: Second Department of Surgery, Hokkaido University School of Medicine, Sapporo, Japan.

⁴ To whom requests for reprints should be addressed, at Department of Pathology, Hahnemann University, Broad and Vine Streets, Philadelphia, PA 19102.

Received 9/ 7/88. Revised 7/13/89. Accepted 11/27/89.