Figure 4.

IFN-γ-secreting cells are abolished by depletion of NK cells in RAG-1-deficient mice. 25 µg of anti-NK1.1 antibody dissolved in 300 µl PBS were administered intraperitoneally to RAG-1-deficient mice on days 2, 5, and 8 before analysis. (A) A flow cytometric analysis with splenocytes stained for NK1.1. Data of cells in the small lymphocyte gate show > 90% reduction of NK1.1+ cells after anti-NK1.1 antibody treatment (Thin, before treatment; Thick, after treatment). Please note that NK cells are abundant in RAG-1-deficient mice since they are lacking in T and B lymphocytes. (B) Splenocytes from control and NK cell-depleted RAG-1-deficient mice were harvested and incubated for 24 h with indicated concentrations of NiSO₄. The number of IFN-γ-secreting cells was counted by the ELISPOT assay.