INDUCTION OF INTERLEUKIN-1-BETA MESSENGER-RNA IN ADULT-RAT BRAIN

The ability of the central nervous system to produce the cytokine interleukin-1β (IL-1β) in response to challenge by activators of the mononuclear phagocyte system has been examined in vivo. Unilateral injection of a mixture of gamma-interferon (IFN-γ) and lipopolysaccharide (LPS) into the forebrain of adult rats induced expression of IL-1β mRNA. In situ hybridization of IL-1β mRNA showed a gradient of cellular hybridization, which was most intense at the site of IFN-γ/LPS injection. The reverse transcription - polymerase chain reaction (RT-PCR) was used to demonstrate the presence of IL-1β mRNA in normal rat brain, and to confirm increases in IL-1β mRNA levels following IFN-γ/LPS injection. These studies show that IL-1β mRNA can be induced to high levels within the CNS as a consequence of exposure to potent stimulators of macrophaga activation. © 1991.