Infection of murine T lymphocytes with lymphocytic choriomeningitis virus: effect of age of mice on susceptibility.

Infectious T lymphocytes were determined in thymuses and spleens of mice acutely infected with LCM virus. Such cells appeared in newborn animals, but their numbers declined when the age at infection increased and none were found in adult mice. Either susceptibility to LCM virus is associated with some degree of immaturity or the probability of murine T lymphocytes to encounter the virus as an infectious entity rather than an immunogen is higher in very young than immunologically mature mice.