TY - JOUR
T1 - Fractalkine is an epithelial and endothelial cell-derived chemoattractant for intraepithelial lymphocytes in the small intestinal mucosa
AU - Muehlhoefer, Andreas
AU - Saubermann, Lawrence J.
AU - Gu, Xuibin
AU - Luedtke-Heckenkamp, Kerstin
AU - Xavier, Ramnik
AU - Blumberg, Richard S.
AU - Podolsky, Daniel K.
AU - MacDermott, Richard P.
AU - Reinecker, Hans Christian
PY - 2000/3/15
Y1 - 2000/3/15
N2 - Fractalkine is a unique chemokine that combines properties of both chemoattractants and adhesion molecules. Fractalkine mRNA expression has been observed in the intestine. However, the role of fractalkine in the healthy intestine and during inflammatory mucosal responses is not known. Studies were undertaken to determine the expression and function of fractalkine and the fractalkine receptor CX3CR1 in the human small intestinal mucosa. We identified intestinal epithelial cells as a novel source of fractalkine. The basal expression of fractalkine mRNA and protein in the intestinal epithelial cell line T-84 was under the control of the inflammatory mediator IL-1β. Fractalkine was shed from intestinal epithelial cell surface upon stimulation with IL-1β. Fractalkine localized with caveolin-1 in detergent-insoluble glycolipid-enriched membrane microdomains in T-84 cells. Cellular distribution of fractalkine was regulated during polarization of T-84 cells. A subpopulation of isolated human intestinal intraepithelial lymphocytes expressed the fractalkine receptor CX3CR1 and migrated specifically along fractalkine gradients after activation with IL-2. Immunohistochemistry demonstrated fractalkine expression in intestinal epithelial cells and endothelial cells in normal small intestine and in active Crohn's disease mucosa. Furthermore, fractalkine mRNA expression was significantly up- regulated in the intestine during active Crohn's disease. This study demonstrates that fractalkine-CX3CR1-mediated mechanism may direct lymphocyte chemoattraction and adhesion within the healthy and diseased human small intestinal mucosa.
AB - Fractalkine is a unique chemokine that combines properties of both chemoattractants and adhesion molecules. Fractalkine mRNA expression has been observed in the intestine. However, the role of fractalkine in the healthy intestine and during inflammatory mucosal responses is not known. Studies were undertaken to determine the expression and function of fractalkine and the fractalkine receptor CX3CR1 in the human small intestinal mucosa. We identified intestinal epithelial cells as a novel source of fractalkine. The basal expression of fractalkine mRNA and protein in the intestinal epithelial cell line T-84 was under the control of the inflammatory mediator IL-1β. Fractalkine was shed from intestinal epithelial cell surface upon stimulation with IL-1β. Fractalkine localized with caveolin-1 in detergent-insoluble glycolipid-enriched membrane microdomains in T-84 cells. Cellular distribution of fractalkine was regulated during polarization of T-84 cells. A subpopulation of isolated human intestinal intraepithelial lymphocytes expressed the fractalkine receptor CX3CR1 and migrated specifically along fractalkine gradients after activation with IL-2. Immunohistochemistry demonstrated fractalkine expression in intestinal epithelial cells and endothelial cells in normal small intestine and in active Crohn's disease mucosa. Furthermore, fractalkine mRNA expression was significantly up- regulated in the intestine during active Crohn's disease. This study demonstrates that fractalkine-CX3CR1-mediated mechanism may direct lymphocyte chemoattraction and adhesion within the healthy and diseased human small intestinal mucosa.
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U2 - 10.4049/jimmunol.164.6.3368
DO - 10.4049/jimmunol.164.6.3368
M3 - Article
C2 - 10706732
AN - SCOPUS:0034654535
SN - 0022-1767
VL - 164
SP - 3368
EP - 3376
JO - Journal of Immunology
JF - Journal of Immunology
IS - 6
ER -