Recruitment of CCR6-expressing Th17 cells by CCL20 secreted from plasmin-stimulated macrophages

Abstract

In the present study, monocyte-derived human macrophages were differentiated from buffy coats. Naïve CD4 1 T-cells enriched from peripheral blood mononuclear cells using anti-CD4 magnetic beads and the autoMACS separation system were polarized under T-helper 17 (Th17)-promoting conditions for 6 days to get Th17 cells. The frequency of Th17 cell differentiation and the expression of C-C chemokine receptor type 6 (CCR6) on Th17 cells were investigated by flow cytometry. Plasmin-triggered induction of macrophage inflammatory protein-3alpha/C-C chemokine ligand 20 (CCL20) genes in macrophages was assessed by reverse transcription-polymerase chain reaction, and secreted protein levels were measured by enzymelinked immunosorbent assay. Th17 cell migration induced by CCL20 secreted from plasmin-stimulated macrophages was tested in vitro by chemotaxis using a transwell system. These results demonstrate that plasmin triggers the expression of chemokine CCL20 messenger RNA and the release of CCL20 protein in human monocyte-derived macrophages, which critically depend on the proteolytic activity of plasmin and activation of p38 mitogen-activated protein kinase and nuclear factor-kappaB signaling pathways. Expression of CCR6 was detected on 87.23 + + + + + 8.6% of Th17 cells in vitro. Similar to chemotaxis triggered by recombinant human CCL20, supernatants collected from plasmin-stimulated macrophage-induced chemotactic migration of Th17 cells, which could be inhibited by an anti-CCL20 neutralizing antibody. These results suggest that plasmin generated in inflamed tissues might elicit production of chemokine CCL20 by human macrophages leading to the recruitment of CCR6 positive Th17 cells to the inflammatory sites.

Bacterial Siderophores That Evade or Overwhelm Lipocalin 2 Induce Hypoxia Inducible Factor 1α and Proinflammatory Cytokine Secretion in Cultured Respiratory Epithelial Cells

“…In turn, CCL20 is a lymphocyte chemoattractant whose expression is amplified by IL-6 production, recruiting Th17 cells to sites of inflammation by binding to its cognate receptor, CCR6. Thus, it is possible that expression of CCL20 initiates an adaptive immune response (45)(46)(47).…”

Recent Advances on Plasmin Inhibitors for the Treatment of Fibrinolysis‐Related Disorders

“…23 Plasmin is a serine protease that exhibits trypsin-like broad specificity, particularly when plasminogen is activated by urokinase plasminogen activator (uPA) in a cell surface receptormediated process. 24,25 Plasmin generated at the cell surface plays a critical role in degradation of extracellular matrix (ECM) resulting in modulation of several processes including tissue remodeling, 26,27 cell invasion and metastasis, 28,29 chemotaxis, 29,30 wound healing and tissue repair, [31][32][33] neuritogenesis, 34,35 ovulation and embryo implantation, 36,37 and others. 38 Plasmin itself can degrade components in the ECM such as laminin, 39 fibronectin, 40 and collagens.…”

THE ROLE OF THE DIFFERENT SUBPOPULATIONS OF CD4⁺Т LYMPHOCYTES DURING PREGNANCY

“…It has been shown in various models that Th17 migration is carried out with participation of CCR6, a receptor for CCL20 [39,75,92,138]. Thus, in the inflammatory conditions, CCL20 produced by macrophages, stimulates Th17 migration [60].…”