Figure 3.

Cytotoxic T lymphocytes degranulation and cytotoxicity are differently impaired in various HLH-prone mouse models. Mice were infected with 200 pfu LCMV i.v. On day 8 after LCMV infection, spleen cells of mutant mice (beige, pearl, souris, STX-11KO, ashen/filled circles) and wild-type (open circle) and PKO (open triangle) mice were restimulated with gp33 peptide or were left in medium without peptide. Surface expression of CD107a of IFN-γ⁺CD8⁺ T cells was determined by flow cytometry as illustrated by (A) representative FACS plots. (B) Percentage of CD107a expressing IFN-γ⁺CD8⁺ T cells after restimulation with gp33 peptide. (C) Correlation of percentage of CTL expressing IFN-γ without restimulation ex vivo with the IFN-γ levels in sera of the various HLH-prone mutant mice. (D) CTL cytotoxicity was determined in a ⁵¹Cr-release assay by using LCMV-infected MC57 target cells.