Effects of interleukin-2 and interferon-beta treatment on lymphocytes in various tumor-bearing mice.

Treatment with a combination of recombinant human interleukin-2 (rHIL-2) and recombinant mouse interferon-beta (rIFN-beta) had a significant antitumor effect against subcutaneous (s.c.) adenocarcinoma-755 and colon-38, but this combination performed no better than rHIL-2 alone against s.c. Lewis lung carcinoma in C57BL/6 mice. Injecting a combination of rHIL-2 and rIFN-beta into mice with adenocarcinoma-755 or colon-38 tumors resulted in a marked increase in L3T4+, Lyt-2+ and asialo GM1+ cells in the peritoneal cavity. On the other hand, the treatment of mice with Lewis lung carcinoma with rHIL-2 and rIFN-beta produced almost no change of each subset in the peritoneal cavity compared to cytokine alone. Thus, sensitive tumors (adenocarcinoma-755 and colon-38) in combined treatment with rHIL-2 and rIFN-beta markedly increased L3T4+, Lyt-2+ and asialo GM1+ cells in the peritoneal cavity, but the insensitive tumor (Lewis lung carcinoma) did not.