Endotoxin stimulates lymphocyte-endothelial interactions in rat
intestinal peyer's patches and villus mucosa.
Miura, Soichiro, Yoshikazu Tsuzuki, Iwao Kurosa, Makoto Suematsu,
Takeharu Shigematsu, Hiroyuki Kimura, Hajime Higuchi, Hiroshi
Serizawa, Hideo Yagita, Ko Okumura, D Neil Granger, and Hiromasa
Ishii.
Departments of Internal Medicine and Biochemistry, School of
Medicine, Keio University, Tokyo, Japan, Department of Immunology,
Juntendo University, School of Medicine, Tokyo, Japan, Department of
Physiology and Biophysics, LSU Medical Center, Shreveport, LA,
USA
APStracts 3:0035G, 1996.
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 non-lymphoid (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,
while 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,
both types of adhesive interaction being mediated by [alpha]4
-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 [alpha]4-integrins and partly by [beta]2-integrins. In
capillaries of intestinal mucosa, lymphocyte adherence occurred
without rolling and was independent of [alpha]4-integrins. LPS also
significantly increased adherence of lymphocytes to villus
capillaries, which was not mediated by either [alpha]4- or [beta]2
-integrin. These observations demonstrate significant heterogeneity of
lymphocyte-endothelial cell interactions within different regions of
the intestinal mucosa.
Received 8 August 1995; accepted in final form 19 January 1996.
APS Manuscript Number G346-5.
Article publication pending Am. J. Physiol. (Gastrointest. Liver
Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 8 February 96