High endothelial venules of the lymph nodes express Fas ligand.
J Histochem Cytochem
; 52(5): 693-9, 2004 May.
Article
in En
| MEDLINE
| ID: mdl-15100246
ABSTRACT
Fas (CD95, APO-1) is widely expressed on lymphatic cells, and by interacting with its natural ligand (Fas-L), Fas induces apoptosis through a complex caspase cascade. In this study we sought to survey Fas-L expression in vascular and sinusoidal structures of human reactive lymph nodes. Immunohistochemical Fas-L expression was present in all paracortical high endothelial venules (HEVs), in cells lining the marginal sinus wall, and in a few lymphocytes, but only occasionally in non-HEV vascular endothelium. In the paracortical zone over 60% of all vessels and all paracortical HEVs showed Fas-L expression, whereas in the medullary zone less than 10% of the blood vessels were stained with Fas-L. Normal vessels outside lymph nodes mostly showed no Fas-L expression. We show that in human reactive lymph nodes Fas-L expression is predominantly present in HEVs. Because the circulating lymphocytes gain entry to nodal parenchyma by transendothelial migration through HEVs, the suggested physiological importance of Fas-L expression in these vessels lies in the regulation of lymphocyte access to lymph node parenchyma by possibly inducing Fas/Fas-L mediated apoptosis of activated Fas-expressing lymphoid cells. The Fas-L expressing cells in the marginal sinus might have a similar function for cells accessing the node in afferent lymph.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Endothelium, Vascular
/
Membrane Glycoproteins
/
Lymph Nodes
Limits:
Adolescent
/
Adult
/
Aged
/
Child
/
Child, preschool
/
Female
/
Humans
/
Male
/
Middle aged
Language:
En
Journal:
J Histochem Cytochem
Journal subject:
HISTOCITOQUIMICA
Year:
2004
Document type:
Article
Affiliation country:
Finland