Fig. 1

Schematic representation of the murine model of virus-associated secondary HLH. HLH-like disease is present in WT and IFN-γ-KO BALB/c mice, not in WT C57BL/6 mice. Mice are infected i.p. with 5 x 10³ PFU of MCMV and analyzed 5 days post infection. * = fever, pancytopenia, hemophagocytosis, hyperferritinemia and elevated soluble CD25 levels; ** = lymphadenopathy, liver dysfunction and decreased NK cell numbers; *** = in addition to WT BALB/c mice also splenomegaly, coagulopathy and decreased NK cell cytotoxicity. ↑ = more pronounced as compared to infected WT BALB/c mice; NK = natural killer; KO = knockout; MCMV = mouse cytomegalovirus; PFU = plaque-forming units; WT = wild-type