[52] Measurement of a receptor for (2′-5′)-oligoadenylate(trimer) on macrophages

Publisher Summary This chapter provides measurement of a receptor for (2'-5')-Oligoadenylate (trimer) on Macrophages. The main component of the (2'-5')-oligoadenylate family is pppA-2'p5'A2'p5'A, briefly (2'-5')P 3 A 3 . It plays an important role in the mechanism of interferon action. These may be natural antiviral substances that can regulate the activity of the immune system. Studies on the biological effects of (2'-5')-oligo(A) usually used CaCI 2 or other agents to introduce the compound into cells. The chapter studies the effect of (2'-5')P 3 A 3 on the activity of natural killer cells and macrophages; (2'-5')P 3 A 3 can directly activate these cells without the addition of CaCI 2 or other substances, and [3H](2'-5')P 3 A 3 can be bound to macrophages. This binding is saturable with high concentration of ligand and also with high concentration of macrophages; reversible; ligand specific and also somewhat cell specific; relevant to its biological effect, because there is a correlation of biological effect with binding for various derivatives; and not due to pinocytosis of bulk liquid. There exists a receptor, which mediates the direct action of (2'-5')P 3 A 3 on macrophages. These observations seem to represent the first report of an oligonucleotide generating a biological effect through a receptor.