SPN and infection: CD43+/+ and CD43-/- mice on a C57BL/6 background were intravenously injected with 5 × 10 7 amastigotes of Leishmania (L.)infantum chagasi, and 30 days after infection the clinical signs of disease were examined; the splenocytes were isolated and assayed for cytokine production; and the livers were removed for phenotypic analysis of T cell subsets by flow cytometry.