Alveolar macrophages (AM) are thought to function as primary effector cells against tumors growing in the lung. Systemic administration of lymphokine activated killer (LAK) cells and IL-2 resulted in partial antitumor response in patients with advance...
Alveolar macrophages (AM) are thought to function as primary effector cells against tumors growing in the lung. Systemic administration of lymphokine activated killer (LAK) cells and IL-2 resulted in partial antitumor response in patients with advanced cancer. LAK activity is influenced by various factors. We studied the effects of AM and blood monocytes from healthy donors on IL-2 enhanced NK activity against K-562 cells and LAK activity against Raji cells utilizing a 4h ^(51)Cr release assay. The following results were obtained: 1) The addition of different doses of human blood monocytes showed no suppression or enhancement of IL-2 enhanced NK and LAK activity. 2) The addition of high dose of AM (Lymphocyte: AM=1:1) significantly suppressed IL-2 enhanced NK activity. Smaller doses of AM (Lymphocyte: AM= 10:1and 100:1) did not suppress IL-2 enhanced NK activity. 3) The addition of high dose of AM (Lymphocyte: AM = 1:1 and 10:1) significantly suppressed LAK activity. The smallest dose of AM (Lymphocyte: AM= 100:1) did not suppress LAK activity. In conclusion, IL-2 enhanced NK and LAK activity were dose-dependently suppressed by human alveolar macrophages. However IL-2 enhanced NK and LAK activity were not suppressed by blood monocytes.