High endothelial venule morphology and function are inducible in germ-free XXXX : a possible role for @entity60 .

@entity19 @entity4973 @entity60
Cytokines may facilitate lymphocyte traffic by modulating @entity4973 structure and lymphocyte binding function in accordance with local tissue requirements. This study investigated whether the morphology of HEVs and their lymphocyte binding ligand are altered following antigenic challenge and evaluated the role of @entity60 in the induction of such changes. The morphology and lymphocyte binding function of mesenteric LN HEVs of GFM exposed to environmental pathogens were compared to those from GFM and conventional @entity19 . Lymph nodes from all @entity19 had microscopically identifiable HEVs. The morphology of HEVs from GFM was not uniform; many HEVs contained flat endothelial cells with sparse cytoplasm and prominent interendothelial gaps. The number of lymphocytes within the lumen and the @entity4973 wall was low. In contrast, HEVs from GFME and conventional @entity19 were characterized by cuboidal endothelial cells with plentiful cytoplasm and large numbers of lymphocytes in the vessel wall and lumen. There was no delineation of interendothelial cell borders. Lymphocyte binding to HEVs of lymph node sections from GFM was reduced (mean +/- SEM: 1.08 +/- 0.15) compared to that of conventional @entity19 (1.91 +/- 0.20), P less than 0.003. GFME had augmented lymphocyte binding (2.23 +/- 0.26) to levels comparable with those of conventional @entity19 . GFM injected intraperitoneally with @entity60 , IFN-alpha beta, or diluent resulted in minor changes in @entity4973 morphology. By contrast, lymphocyte binding to @entity4973 of GFM was more than doubled by the injection of @entity60 (1.95 +/- 0.25), P less than 0.01, but not IFN-alpha beta (0.54 +/- 0.07) or the relevant diluent controls (0.89 +/- 0.11, 0.56 +/- 0.06, respectively). It appears that the @entity4973 binding ligand is inducible, and its expression is regulated by at least one immunomodulator, @entity60 . Although short-term exposure of HEVs to @entity60 influenced @entity4973 function it caused only minor changes in morphology.
