β-Endorphin protects mice from neurological disease induced by the murine coronavirus MHV-JHM

The neurotropic murine coronavirus, MHV-JHM (JHMV) causes encephalitis and paralytic-demyelinating disease in susceptible strains of mice and rats, serving as a model for human demyelinating diseases such as multiple sclerosis. In this communication, we report that a single intracerebral administration of the naturally occurring neuropeptide, β-endorphin, reduced the incidence of JHMV-induced paralytic-demyelinating disease 40–50% in C57Bl/6 mice. Protection from disease was accompanied by significantly reduced virus replication in the brain as early as 3 days post-infection and did not occur in irradiated, or immunoincompetent mice. The data suggest that β-endorphin engages immune mechanisms of host resistance to JHMV infection to protect the mice from disease.