Lymphocytic Choriomeningitis Virus (LCMV): Agent for Neurological Diseases and Model for Studying Human Viruses

Lymphocytic choriomeningitis virus (LCMV) is an arenavirus—single-stranded RNA virus. It causes asymptomatic infection in rodents and was identified more than a decade ago in the USA. Though rodents are the main reservoir for LCMV, it can also be transmitted to humans directly or indirectly (through congenital disease or organ donation). Human viral encephalitis caused by LCMV infection can spread through mice, usually starting in the late autumn. LCMV is not a lytic virus and is capable of producing robust lymphocyte cytotoxic responses and triggering inflammation. It enters via aerosol and settles in the lungs causing edema. It then travels via blood to the “meninges,” “choroid plexus,” and “ventricular ependymal linings,” where the virus replicates. Currently, no antiviral therapy, other than “favipiravir,” is promising. A number of important concepts have arisen with the use of LCMV as a model pathogen such as “major histocompatibility complex (MHC) restriction,” “T-cell memory,” chronic infections, exhaustion of T cells, and a major role in the identification of immune-dominant and subdominant T-cell epitopes. This viral system has also been used to identify tolerance, autoimmune tissue damage, and the efficacy of treatment interventions and vaccine preparations. The knowledge and progress of immunology have greatly benefitted from studying this virus.