Differential IL-1 Synthesis by Astrocytes from Theilerʹs Murine Encephalomyelitis Virus-Susceptible and -Resistant Strains of Mice

Increasing evidence shows that interleukin-1 (IL-1) contributes to inflammatory processes, such as experimental allergic encephalomyelitis (EAE) and virus-induced demyelination, inside the central nervous system (CNS). Using primary cultures of mouse astrocytes, we show that these glial cells can be induced to produce IL-1α when infected with Theilerʹs murine encephalomyelitis virus (TMEV). This was true for astrocytes from SJL/J mice, a strain susceptible to TMEV-induced demyelination. Conversely, BALB/c astrocytes, derived from animals genetically resistant to demyelination, did not produce IL-1α in detectable amounts. Therefore, a differential IL-1 gene expression, which is strain specific, is demonstrated after TMEV infection in astrocytes. The release of IL-1α by SJL astrocytes was studied from kinetic, infectivity, and immunochemical points of view. Since IL-1 plays a critical role in the immune response, its production by astrocytes in some strains of mice may contribute to virus-induced susceptibility and to inflammation associated with this experimental model of multiple sclerosis.