File:Lymph node - high endothelial venule.jpg: Difference between revisions

Lymph Node - High Endothelial Venule

Chemokines and chemokine-binding molecules expressed in and around high endothelial venules (HEVs) in a concentric manner might function coordinately in lymphocyte trafficking across HEVs.

Original authors propose that several chemokine-binding molecules are expressed in a concentric manner in HEVs and their surrounds. The coordinated actions of chemokines and chemokine-binding molecules in and around HEVs are shown schematically in sequential order.

• a - In the lumen of HEVs, heparan sulphate proteoglycans (red) can capture and present a lymphoid chemokine (X, green) in situ. Duffy antigen receptor for chemokines (DARC; black) — a non-signalling chemokine receptor — captures and scavenges inflammatory chemokines, such as CXC-chemokine ligand 1 (CXCL1; pink), which is constitutively produced by HEVs.
• b - n the basal lamina of HEVs, another chemokine-binding protein MAC25 (dark blue) can capture a chemokine, such as CC-chemokine ligand 21 (CCL21), CXCL10 or CCL5 (Y, light blue). In addition, other components in the basal lamina such as collagen and fibronectin (grey) can capture a different chemokine (Z, yellow) expressed in the HEV area.
• c - When lymphocytes rolling along the HEV endothelium recognize chemokine X presented in the lumen, they are signalled to activate their integrins and firmly adhere to HEVs.
• d - Subsequently, some of the adhering lymphocytes migrate across HEVs and are stimulated by chemokine Y, which is immobilized on MAC25.
• e - Farther outside, other chemokine-binding molecules, such as collagen IV and fibronectin, can capture a different chemokine (Z). Some of the extravasating lymphocytes might interact with chemokine Z and be stimulated to move into this area.
• f - By sequentially recognizing the multiple chemokines presented on the tissue matrix, more and more lymphocytes extravasate and progressively move from the inside to the outside of HEVs.

See also Lymph node cartoon.

Lymph Node Cartoons: Detailed structure | Cartoon with Histology | Lymphocyte traffic | Simple structure | Simple node anatomy | Wiki node image | Internal structure | Mesenteric lymph node | Histology | Gallery | Lymph Node Development

Reference

<pubmed>15122201</pubmed>| Nat Rev Immunol.

Adapted by permission from Macmillan Publishers Ltd: Nat. Rev. Immunol.: 2004, 4(5);360-70, copyright (2004)

Licensee: Mark A Hill License Number: 2857291045727 Publication: Nature Reviews Immunology

Title: Lymphocyte trafficking across high endothelial venules: dogmas and enigmas Type Of Use: post on the internet

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