Fig. 7. Influence of low serum iron on NK cells during acute FV infection.

C57BL/6 mice were infected i.v. with FV for 7 days or used as uninfected, naive control. Mice were treated every day i.p. with DSPE (vehicle) or mini-hepcidin (mHep) in DSPE. At the day of the experiment, bone marrow (BM) and spleens were harvested and stained for analysis by flow cytometry. NK cells were analysed for cell size (FSC, a) and for cMyc (b). NK cells were isolated from spleens of naive + vehicle and FV-infected mice (FV + vehicle and FV + mHep) and co-incubated with Tag-it-Violet stained FV-induced FBL-3 tumour cells. After co-incubation, co-culture was stained for viability and analysed by flow cytometry (c). Viral loads were detected by an Infectious Center assay in bone marrow and spleen and analysed by a two-sided Mann–Whitney test (d). At least five mice per group from two independent experiments were used. Statistically significant differences between the groups were analysed with an Ordinary one-way ANOVA (a–c). The cell culture medium of in vitro expanded NK cells was modified for iron availability (DFO) and additional iron (FeSO₄) was added if indicated. NK cells were analysed for cell size (e), MitoTracker Green (f), perforin (g) and granzyme B (h). Experiments were performed once with four biological replicates. Statistically significant differences were analysed by an ordinary one-way ANOVA with a Sidak post-test. NK cells (NK1.1⁺CD4⁻CD8⁻) were depleted with an anti-NK1.1 depletion antibody and depletion efficiency is shown in i. At 3 dpi, viral loads of FV-infected, mHep-treated ± NK cell depletion is displayed in j and were analysed by a two-sided unpaired t-test. All data are presented as mean values ± SEM. *p < 0.05, **p < 0.01, ***p < 0.001. Source data are provided as a Source Data file. ns not significant.