Protective Effect of Anti-lymphocytic Serum on Murine Lymphocytic Choriomeningitis

Abstract

LYMPHOCYTIC choriomeningitis (LCM) virus inoculated intracerebrally into mice produces a disease that is usually fatal. Such infections are, however, rarely fatal in mice that have been X-irradiated^1,2 or treated with radiomimetic drugs³, although they carry the virus in high concentration indefinitely. These and other observations suggested that the lethal disease results from a hypersensitive reaction against the virus or against some product of the virus^4,5, and certain evidence seems to implicate cells of the central nervous system in this reaction⁶. Congenitally infected mice do not develop acute illness, although they maintain high levels of viraemia throughout their lives⁷. When such mice are inoculated with adequate numbers of histo-compatible lymphocytes from immunized animals no sign of illness develops, but the level of viraemia is greatly reduced⁸. This observation appears to conflict with the hypothesis that severe lymphocytic choriomeningitis is a manifestation of a hypersensitivity reaction.