Endotoxin stimulates lymphocyte-endothelial interactions in rat intestinal Peyer's patches and villus mucosa
Miura, S.; Tsuzuki, Y.; Kurose, I.; Suematsu, M.; Shigematsu, T.; Kimura, H.; Higuchi, H.; Serizawa, H.; Yagita, H.; Okumura, K.; Granger, D.N.; Ishii, H.
American Journal of Physiology 271(2 Pt 1): G282-G292
1996
ISSN/ISBN: 0002-9513 PMID: 8770044 Document Number: 461498
Although lymphocyte-endothelial cell interactions represent a key step in controlling the recruitment of lymphocytes into gut-associated tissues, its dynamic process in microvessels of lymphoid (Peyer's patches) and nonlymphoid (villus) regions of the small bowel remains poorly understood. We monitored the migration of fluorescence-labeled T lymphocytes into normal and lipopolysaccharide (LPS)-inflamed rat intestinal microvessels using intravital microscopy. In Peyer's patches, T lymphocytes selectively adhered to postcapillary venules, although such selectivity was not observed in submucosal venules of villi. T lymphocytes exhibited rolling behavior followed by firm adhesion in microvessels of both the Peyer's patches and the villi, with both types of adhesive interaction being mediated by a4-integrins. The enhanced rolling and adherence of lymphocytes observed in Peyer's patches and submucosal venules of villi of LPS-treated rats were preceded by a reduction in shear rate and were mediated largely by a4-integrins and partly by b2-integrins. In capillaries of intestinal mucosa, lymphocyte adherence occurred without rolling and was independent of a4-integrins. LPS also significantly increased adherence of lymphocytes to villus capillaries, which was not mediated by either a4- or b2-integrin. These observations demonstrate significant heterogeneity of lymphocyte-endothelial cell interactions within different regions of the intestinal mucosa. Reprinted by permission of the publisher.