Further experiments on the action of antithymocyte serum in experimental Junín virus infection.

Rabbit anti-mouse thymocyte serum (ATS) administrated as late as 7 days after infection suppressed host cell-mediated responsiveness to intracerebrally injected Junín virus, thereby diminishing the morbility and mortality of this infection. It did not affect either the humoral antibody response or the virus titer in brain. This findings suggest that: a) in mouse brain cells, Junín virus infection is basically non-cytopathic: b) cell-mediated immunity is responsible for morbility and mortality and does not clear up virus from brain as in other viral encephalitides; and c) ATS may be of therapeutic interest by suppressing or diminishing the cell-mediated response to Junín virus.