Figure 8. Influenza-specific CD8⁺ T-cell produced solTNFR2 regulates the availability of solTNF-α.

To investigate the regulation of solTNF-α levels by solTNFR2 in activated CD8⁺ T cells, NP_366–374-specific CD8⁺ T cells were stimulated in vitro with peptide (A) TNFR2 and TNF-α expression on peptide-stimulated or TAPI-treated, peptide-stimulated WT CD8⁺ T cells after 1 h of stimulation was examined by confocal microscopy. Arrows indicate colocalization of TNFR2 and TNF-α. (B) Effects of blocking antibody for TNFR2 on solTNF-α expression after 1 h of peptide stimulation of WT CD8⁺ T cells, as measured by ELISA. (C) Total intracellular production of TNF-α and IFN-γ by peptide-stimulated WT or TNFR2^−/− CD8⁺ T cells after 4 h of stimulation, as assessed by flow cytometry. (D) ELISA was used to measure solTNF-α and IFN-γ production by peptide-stimulated WT or TNFR2^−/− CD8⁺ T cells after 4 h of stimulation. (E) ELISA was used to measure solTNF-α levels after the addition of increasing concentrations of recombinant solTNFR2 to cultures of peptide-stimulated TNFR2^−/− CD8⁺ T cells. Data represent means ± sd. Data are representative of 2 independent experiments, with each condition conducted in triplicate. *P < 0.05.