Local low-dose IL-2 therapy.

Interleukin-2 (IL-2) is a powerful drug for treating cancer. However, it is only powerful if it is properly applied. That is, IL-2 should be applied at the tumor site, because at the transition of normal and malignant tissue are the tumor infiltrating cells.

Monitoring of CD95 (APO-1/Fas) ligand expression in human T cells by quantitative RT-PCR.

CD95 (APO-1/Fas) receptor/ligand interaction is a key regulatory pathway for apoptosis in lymphoid cells. We developed a quantitative RT-PCR for the human CD95-L to determine expression levels in lymphoid cell lines and in lymphocytes derived from blood of healthy individuals. In untreated peripheral blood T lymphocytes and T cell lines constitutive expression of the CD95-L mRNA was found at low levels.

Specific tumor memory induced by polyethylene-glycol-modified interleukin-2 requires both helper and cytotoxic T cells.

Local polyethylene-glycol (PEG)-modified interleukin-2 (IL-2) immunotherapy of the guinea pig Line 10 (L10) tumor was previously demonstrated to evoke long-lasting systemic immunity after cure of the tumor and metastases. T cells, most likely the helper T cell subpopulation, were demonstrated to be crucial to the antitumor effects. Here we show that systemic immunity is induced within 7 days after the start of PEG-IL-2 therapy, indicating a rapid systemic priming of L10-specific T cells.

PEG-IL-2 therapy of advanced cancer in the guinea pig. Impact of the primary tumor and beneficial effect of cyclophosphamide.

The efficacy of tumor therapy using polyethylene-glycol-modified interleukin-2 (PEG-IL-2), alone or in combination with cyclophosphamide, was studied in advanced metastatic disease in the guinea pig. Line 10 (L10) tumor cells appeared in the axillary lymph node only 7 days after intradermal tumor-cell inoculation, and lymph-node leukocytes were almost completely replaced by tumor cells on day 28. Local treatment of the intradermally growing L10 hepatocarcinoma in the guinea pig with a relatively low dose of PEG-IL-2 resulted in regression of the primary tumor and prevention of lymph-node metastases.