Suppressor T-cell population induced by Junin virus in adult mice.

Intracerebral (i.c.) Junin virus (JV) infection of adult BALB/c mice is characterized by the absence of morbidity and a low mortality (barely 8-10%). In contrast, the suckling mouse model exhibits almost 100% mortality following central nervous system (CNS) alterations consistent with a delayed-type hypersensitivity (DTH)-like immune response. Besides, JV infection of adult (resistant) mice leads to immunosuppression of DTH to unrelated antigens. Here we present evidence demonstrating that such suppression is mediated by JV-induced cells present in spleen from 24 hr to 24 days post-infection, bearing the Thy-1+, Ly-1+2- phenotype and reactive to an unrelated antigen such as sheep red blood cells (SRBC). No evidence of suppressor factors was found. A relatively low number of total splenic cells (5 x 10(6) cells/mouse) was enough to transfer suppression. Therefore, this cell population may be involved in adult mouse survival to JV infection.