Mortality induced by adoptive immunity in Junin virus-infected athymic mice

The effect of normal or sensitized spleen cell transfer from syngeneic euthymic mice to Junin virus-infected suckling athymic mice was studied. Transfer was performed 1 or 7 days after infection. In both cases, an acute lethal disease developed 6-11 days after transfer. The mortality reached 100% in all infected groups receiving normal or sensitized splenocytes, while it was negligible for different control groups of athymic mice. Transfer of normal or sensitized splenocytes was unable to significantly modify brain viral titers, as compared with infected nontransferred athymic mice killed after a 25-day observation period. Brain lesions were demonstrated in about half of the infected athymic mice transferred with sensitized splenocytes and in all euthymic infected mice. These results show that splenocyte transfer from immunocompetent donors is able to change the normal course of persistent Junin virus infection in nude mice to a lethal acute disease, thus pointing to a main role for T cells in its pathogenesis.