Macrophage migration inhibitory factor stimulates interleukin-17 expression and production in lymph node cells

Area of Science:

• Immunology
• Molecular Biology
• Cell Biology

Background:

• Interleukin-17 (IL-17) is a pro-inflammatory cytokine produced by T helper type 17 (Th17) cells.
• Th17 cells play a critical role in immunity and the pathogenesis of autoimmune disorders.
• IL-6 and transforming growth factor-beta (TGF-β) are crucial for Th17 cell generation, while other cytokines support IL-17 production.

Purpose of the Study:

• To investigate the influence of macrophage migration inhibitory factor (MIF) on IL-17 production in mice.
• To determine the signaling pathways involved in MIF-mediated IL-17 regulation.
• To explore the therapeutic potential of targeting MIF for inflammatory and autoimmune diseases.

Main Methods:

• Treatment of mouse lymph node cells (LNCs) with recombinant MIF.
• Analysis of IL-17 production in MIF knockout (mif(-/-)) and wild-type (WT) mice.
• Stimulation of LNCs with various cytokines (IL-1β, IL-23, TNF-α, IL-6, TGF-β).
• Assessment of IL-17 levels in vivo after complete Freund's adjuvant injection.
• Investigation of signaling pathways including p38, ERK, JNK, Jak2/STAT3, NF-κB, and NFAT.

Main Results:

• Recombinant MIF treatment up-regulated IL-17 expression and secretion in LNCs.
• MIF knockout mice exhibited significantly impaired production of IL-17 and related cytokines (IL-1β, IL-6, IL-23, TGF-β).
• MIF deficiency reduced IL-17 secretion and the number of IL-17-positive cells in vivo.
• MIF's effect on IL-17 production was dependent on p38, ERK, JNK, and Jak2/STAT3 signaling pathways, but not NF-κB or NFAT.

Conclusions:

• MIF plays a significant role in regulating IL-17 production in mice.
• Targeting MIF biological activity presents a potential therapeutic strategy for inflammatory and autoimmune diseases.
• The findings elucidate the molecular mechanisms underlying MIF-mediated IL-17 regulation.