Impact of IAP antagonist on naïve T cells and APC function of the spleen. (A) To evaluate the impact of IAP antagonist on naïve T cells, WT mice were pretreated intraperitoneally with LBW242 or solvent for 7 days. Three days after the last application, the mice were infected intravenously with 200 PFU LCMV. On day 8 post-infection, total leukocyte counts, percent and total counts of CD8 T cells, and GP33-specific T cells were determined in the spleen (upper panels). KLRG-1 upregulation, as well as total numbers of IFNγ- and TNF-expressing CD8 T cells were calculated. Viral titres in the spleens were determined in a virus focus forming assay (lower panels). (B) Antigen presenting function of splenocytes from day 4 LCMV-infected WT mice, treated during infection with LBW242 or solvent, was tested with CFSE-labeled P14 T cells in an in vitro proliferation assay. Data are representative of 2 to 3 independent experiments.