IL-8 secretion and neutrophil activation by HT-29 colonic epithelial cells.
This study examines the ability of HT-29 human colonic epithelial cells to stimulate neutrophil migration and adhesion. Interleukin-8 (IL-8), a potent neutrophil chemoattractant, was detected in conditioned media from both unstimulated (1.1 ng/ml) and IL-1 beta-stimulated (16.1 ng/ml) HT-29 cultures. Conditioned medium from IL-1 beta-exposed HT-29 cells stimulated neutrophil migration (395% of control, P < 0.01), and this effect was completely inhibited by anti-IL-8 antibody. HT-29 medium also induced shedding of neutrophil L-selectin and increased expression of neutrophil CD11/CD18 adhesion receptors. Coculture of HT-29 cells with human endothelial cell monolayers resulted in increased neutrophil transendothelial migration (169% of control, P < 0.01), which was blocked by both anti-IL-8 and anti-CD18 antibody. Northern hybridization analysis demonstrated increased levels of mRNA for IL-8 and intercellular adhesion molecule-1 (ICAM-1) in cytokine-treated HT-29 cells. Cytokine stimulation of HT-29 monolayers was also associated with increased neutrophil adhesion to these cells. Neutrophil-HT-29 cell adhesion was blocked by monoclonal antibodies to neutrophil CD18 or to ICAM-1 on the HT-29 cells (86% and 56% inhibition, respectively, P < 0.01 for both). These data suggest that IL-8 secretion by activated colonic epithelial cells may contribute to neutrophil extravasation and tissue infiltration in intestinal inflammation.
Kelly
C P
CP
Section of Gastroenterology, Evans Memorial Department of Clinical Research, Boston University School of Medicine 02118.
Keates
S
S
Siegenberg
D
D
Linevsky
J K
JK
Pothoulakis
C
C
Brady
H R
HR
D015152:Blotting, Northern; D002448:Cell Adhesion; D002465:Cell Movement; D002478:Cells, Cultured; D003106:Colon / Q000166:cytology / Q000502:physiology*; D017077:Culture Media, Conditioned; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000032:analysis / Q000235:genetics; D016209:Interleukin-8 / Q000235:genetics / Q000378:metabolism*; D016177:Macrophage-1 Antigen / Q000032:analysis; D009504:Neutrophils / Q000502:physiology*; D012333:RNA, Messenger / Q000032:analysis
D017077:Culture Media, Conditioned; D016209:Interleukin-8; D016177:Macrophage-1 Antigen; D012333:RNA, Messenger; D018799:Intercellular Adhesion Molecule-1