Junin virus-induced non-specific suppressor cells interact with unrelated antigen-specific suppressor cells

Junin virus (JV) infection of adult (resistant) BALB/c mice induces antigen non-specific delayed-type hypersensitivity (DTH) suppressor T cells, termed Tsv, bearing the Thy-1+, Ly-1+2- phenotype. These cells may be related to survival to infection since DTH reaction is associated with lethal meningoencephalitis. Employing several xenogeneic red blood cell (RBC) sensitization schedules to induce different cell subpopulations, we have attempted to establish the target of JV-induced suppressor cells (Tsv). The target of Tsv cells was actually included in the antigen-specific suppressor cell compartment, as demonstrated for the RBC system. Tsv cells were able to trigger suppressor cells to act without loss of their specificity. The presence of two sets of sheep RBC-induced DTH suppressor cells bearing the Ly-1+2- and Ly-1-2+ phenotypes was disclosed in low (10(6))-dose sensitized mice. Both sets were simultaneously required by Tsv to achieve DTH suppression. In contrast, in high (10(8] SRBC-dose sensitized animals treated with cyclophosphamide (doses of 50 mg/kg), a single Ly-1-2+ suppressor cell was required.