Fig 1: Model for Fas/FasL regulating mROS and IFN-γ production after IL-12/IL-18 stimulation.Left, IL-12/IL-18 stimulation triggers mitochondria activation and mROS production, which activate the pathway leading to IFN-γ expression. Fas/FasL interaction leads to cytochrome C release, which controls mitochondrial activity and mROS production [39] and, consequently, IFN-γ. Caspase-3 is located outside of mitochondria [58], but there is no apoptosis induction in response to IL-12/IL-18. Right, In absence of Fas, cytochrome C is retained in mitochondria and mROS production is increased. Fas deficiency provokes caspase-3 translocation to mitochondria after IL-12/IL-18 stimulation, which might further increase mROS production [54]. Overall, increased mROS production results in IFN-γ hyperproduction in absence of Fas/FasL interaction.
Fig 2: Fas/FasL interaction restricts mROS and IFN-γ production in memory-like CD4+ T cells.A Immunoblot analysis of memory-like CD4+ T cells from C57BL/6 (WT) and C57BL/6-lpr mice (Faslpr) mice stimulated with IL-12/IL-18. B Representative confocal microscopy images of memory-like CD4+ T cells from WT and Faslpr mice stimulated with IL-12/IL-18 or IL-12/IL-18 + DPI or MitoQ for 15 min and stained with anti-p65 antibody and DAPI to visualize p65 nuclear translocation. C Quantification of confocal microscopy images showing nuclear p65 abundance from two independent experiments and a minimum of 20 cells per condition. D Flow cytometry analysis of WT mitoSOXhi population at 30 min after IL-12/IL-18 stimulation in presence of soluble FasL and zVAD. E qRT-PCR analysis of IFN-γ and IL-2 (1 h after stimulation), F IFN-γ protein levels and G immunoblot analysis of WT cells after IL-12/IL-18 stimulation in presence of soluble FasL and zVAD. H Immunoblot analysis of mitochondrial and cytosol fraction in WT and Faslpr memory-like CD4+ T cells stimulated with IL-12/IL-18 for 1 h. For A, G, and H, representative gels of two experiments are shown and β-actin was used as loading control. Graphs show mean ± SD (n = 3 different mice); *p < 0.05; **p < 0.01; ***p < 0.001; ****p < 0.0001; two-way ANOVA with Sidak’s correction.
Supplier Page from Enzo Life Sciences, Inc. for FasL (soluble) (human), (recombinant)