Contrasting roles for CXCR2 during experimental colitis.
Neutrophil recruitment into the colon is believed to play a crucial pathogenic role in the progression of clinical and experimental inflammatory bowel diseases (IBDs). The chemokine receptor CXCR2 is highly expressed on neutrophils, and promotes neutrophil recruitment in several inflammatory diseases. The present study determined the biological role of CXCR2 during trinitrobenzene sulfonic acid (TNBS)-induced colitis in the rat by assessing effects of CXCR2 antibody neutralization on neutrophil accumulation during the early (8 h) and late phase (day 7) of TNBS-induced colitis. CXCR2 expression was elevated (>3-fold above control) within 8 h and remained elevated to day 7 of colitis induction, in parallel with significant increases in neutrophil infiltration. Treatment of colitic rats with a single dose of CXCR2 neutralizing antibody significantly reduced colonic neutrophil accumulation during the early (8 h) phase of TNBS-induced colitis. However, chronic administration of CXCR2 antibody did not reduce colonic neutrophil accumulation during the late phase (day 7) of TNBS-induced colitis. In summary, the present findings suggest a functional role for CXCR2 in initiating neutrophil recruitment during the early phase of TNBS-induced acute colitis, and demonstrate that: early colonic neutrophil accumulation is CXCR2 dependent and the late phase colonic neutrophil accumulation is CXCR2 independent.
Ajuebor
Maureen N
MN
Gastrointestinal Research Group, Faculty of Medicine, University of Calgary, Calgary, AB, Canada T2N 4N1. ajuebor@ucalgary.ca
Zagorski
John
J
Kunkel
Steven L
SL
Strieter
Robert M
RM
Hogaboam
Cory M
CM
D000818:Animals; D019138:Antibodies, Blocking / Q000494:pharmacology; D019743:Chemokines, CXC / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D003092:Colitis / Q000139:chemically induced / Q000378:metabolism* / Q000473:pathology; D004195:Disease Models, Animal; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D008297:Male; D020556:Neutrophil Infiltration / Q000187:drug effects / Q000502:physiology*; D009504:Neutrophils / Q000187:drug effects / Q000473:pathology; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D023063:Receptors, Interleukin-8B / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D014302:Trinitrobenzenesulfonic Acid / Q000633:toxicity
D019138:Antibodies, Blocking; D019743:Chemokines, CXC; D036341:Intercellular Signaling Peptides and Proteins; D012333:RNA, Messenger; D023063:Receptors, Interleukin-8B; D014302:Trinitrobenzenesulfonic Acid