SP and IL-33 together markedly enhance TNF synthesis and secretion from human mast cells mediated by the interaction of their receptors

• Published in: Proceedings of the National Academy of Sciences - PNAS 2017-05, Vol.114 (20), p.E4002-E4009
• Main Authors: Taracanova, Alexandra, Alevizos, Mihail, Karagkouni, Anna, Weng, Zuiy, Norwitz, Errol, Conti, Pio, Leeman, Susan E., Theoharides, Theoharis C.
• Format: Article
• Language: English
• Subjects: Amplification; Biological Sciences; Biphenyl Compounds; Cell Line, Tumor; Cells; Cord blood; Cytokines; Gene expression; Humans; Inflammation; Interleukin 1; Interleukin-1 Receptor-Like 1 Protein - metabolism; Interleukin-33 - metabolism; Luteolin - chemistry; Luteolin - metabolism; MAP Kinase Signaling System; Mast cells; Mast Cells - metabolism; Mast Cells - secretion; Neurokinin; Neurokinin NK1 receptors; Neutralizing; NF-kappa B - metabolism; Peptides; Phosphorylation; Piperidines; PNAS Plus; Pretreatment; Receptors; Receptors, Neurokinin-1 - metabolism; Ribonucleic acid; RNA; Rope; siRNA; Substance P - metabolism; Tumor necrosis factor; Tumor Necrosis Factor-alpha - biosynthesis; Tumor Necrosis Factor-alpha - secretion; Tumor necrosis factor-TNF; Umbilical cord
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.1524845114

The peptide substance P (SP) and the cytokine tumor necrosis factor (TNF) have been implicated in inflammatory processes. Mast cells are recognized as important in inflammatory responses. Here, we report that IL-33 (30 ng/mL), a member of the IL-1 family of cytokines, administered in combination with SP (1 μM), markedly increase (by 1,000-fold) TNF gene expression in cultured human LAD2 and primary mast cells derived from umbilical cord blood. SP (0.01–1 μM) and IL-33 (1–100 ng/mL) in combination also greatly stimulate TNF secretion (by 4,500-fold). Pretreatment of LAD2 cells with two different neurokinin-1 (NK-1) receptor antagonists and siRNA inhibits TNF secretion by 50% (P < 0.001) when stimulated by SP and IL-33. Pretreatment of LAD2 cells with a neutralizing antibody for IL-33 receptor, ST2, inhibits TNF secretion by 50% (P < 0.001), and ST2 siRNA decreases TNF secretion by 30% (P < 0.05), when stimulated by SP and IL-33. Surprisingly, NK-1 antagonists also inhibit 50% of TNF secretion (P < 0.001) when stimulated only by IL-33, and ST2 receptor reduction also decreases SP-stimulated TNF secretion by 30% (P < 0.05), suggesting an interaction between NK-1 and ST2 receptors. Moreover, IL-33 increases NK-1 gene and surface protein expression, as well as IKβ-α phosphorylation. Pretreatment of LAD2 cells with 5,7,3′,4′-tetramethoxyflavone (methoxyluteolin) (1–100 μM) inhibits (P < 0.001) TNF gene expression (98%) and secretion (64%) at 50 μM and phosphorylation of p-IKB-α at 1 μM when stimulated by SP and IL-33. These findings identify a unique amplification process of TNF synthesis and secretion via the interaction of NK-1 and ST2 receptors inhibitable by methoxyluteolin.