S. Sato et al., CENTRAL-NERVOUS-SYSTEM CYTOKINE MESSENGER-RNA EXPRESSION FOLLOWING THEILERS MURINE ENCEPHALOMYELITIS VIRUS-INFECTION, Journal of neuroimmunology, 76(1-2), 1997, pp. 213-223
DA strain of Theiler's murine encephalomyelitis virus (TMEV) produces
a biphasic disease with an initial self-limited acute gray matter poli
oencephalomyelitis in all strains of mice followed by, in the case of
certain susceptible strains of mice, a chronic inflammatory demyelinat
ion of the spinal cord with a persistent virus infection. A pathogenic
role for T-helper 1 (Th1) cells during the demyelinating phase of dis
ease has been proposed. We characterized the cytokine mRNA expression
in the brain and spinal cord of susceptible and resistant strains of m
ice during the early encephalomyelitic disease and the late demyelinat
ion, using a semi-quantitative reverse transcription-polymerase chain
reaction (RT-PCR) assay. At the time of the encephalomyelitis, both re
sistant and susceptible mice expressed proinflammatory cytokine mRNAs
followed by T-cell derived mRNAs; susceptible mice expressed more IL-1
2 p40 mRNA than resistant mice. During this early disease, there was n
o significant difference in Th1 cytokine mRNA expression in the brain
and spinal cord among the four strains and relatively little Th2 type
cytokine upregulation above levels seen in mock-infected controls. Dur
ing the late demyelinating disease, susceptible but not resistant mice
had evidence of viral genome and a continuous expression of Th1 type
cytokine mRNAs. The expression of Th2 cytokine mRNAs varied among the
different strains and did not correlate with susceptibility or resista
nce. The results indicate the complexity of cytokine mRNA expression f
ollowing TMEV infection and the dependence of the expression on diseas
e pathology, the time following infection and the genetics of the host
.