Viral Interference induced in Mice by Acute or Persistent Infection with the Virus of Lymphocytic Choriomeningitis

Abstract

CONGENITAL or neonatal infection of mice with the virus of lymphocytic choriomeningitis (LCM) is often characterized by prolonged survival of the host, persistence of virus in the tissues, chronic viræmia and failure to develop specific antibodies¹. This ‘persistent tolerated infection’ has been likened to the phenomenon of immunological tolerance². Despite inability to form neutralizing antibody, adult mice previously infected at or before birth with LCM virus also exhibit the capacity to withstand challenge with homologous virus in a dose that would readily kill uninfected adult mice³. It has been postulated³ that this resistance to superinfection (tolerant immunity) is related to lack of an allergic tissue response to LCM virus in the immunologically unresponsive host. Another possible explanation is that LCM virus in the tissues of the persistently infected mouse acts as an interfering agent⁴ in much the same way that LCM virus interferes with poliovirus in the monkey⁵.