Immunological Study of Interleukin-2 in the Patients with Malignant Brain Tumors

The authors studied the capacity of peripheral blood lymphocytes from patients with malignant brain tumors to produce, and to respond to, interleukin-2 (IL-2). The role of IL-2 in generation of T cells cytotoxic to tumor cells was also studied. Lymphocytes from the patients with malignant brain tumors produced less IL-2 than did those of normal controls. However, phytohemagglutinin-activated peripheral blood lymphocytes from normal controls and the patients responded equally well to IL-2. This indicates that IL-2 receptors are abundant in the patients' lymphocytes, although IL-2 production may be depressed. Furthermore, after incubation with IL-2, lymphocytes from patients with malignant glioma exhibited higher natural killer activity and strong cytotoxicity to glioma cells. Its tumor cell cytotoxicity makes IL-2 a likely candidate for use in adoptive immunotherapy.