Molecular cloning and expression analysis of the canine chemokine receptor CCR9.
The chemokine receptor CCR9, which interacts with the thymus-expressed chemokine TECK/CCL25, contributes to the localization of lymphocytes to the small intestine, and is implicated in the development of human inflammatory bowel disease (IBD); however, their role in canine IBD is unknown. The objective of this study was to isolate cDNA encoding CCR9 and to investigate CCR9 expression in normal canine tissues and lymphoid cell lines. The complete open reading frame contained 1104 bp, encoding 367 amino acids, with 85% and 81% identity to human and mouse homologs, respectively. CCR9 mRNA was detected in all tissues investigated with the highest expression level in the small intestine. CCR9 mRNA was also expressed in GL-1, a canine B cell leukemia cell line, but not in CLBL-1, a canine B cell lymphoma cell line. Immunoblot and flow cytometry analyses of these cell lines using an anti-human CCR9 monoclonal antibody revealed that CCR9 protein expression was detected only in GL-1, indicating the cross-reactivity of the antibody. Using the antibody, flow cytometry showed that the proportions of CCR9(+) cells were small (mean, 4.88%; SD, 2.15%) in the normal canine PBMCs. This study will be useful in understanding canine intestinal immunity and the immunopathogenesis of canine IBD.
Department of Veterinary Internal Medicine, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Tokyo 113-8657, Japan.
Shingo
S
Maeda
Koichi
K
Ohno
Atsushi
A
Tsukamoto
Ko
K
Nakashima
Kenjiro
K
Fukushima
Yuko
Y
Goto-Koshino
Yasuhito
Y
Fujino
Hajime
H
Tsujimoto
D000595:Amino Acid Sequence; D000818:Animals; D045744:Cell Line, Tumor; D019976:Cloning, Organism; D018076:DNA, Complementary / Q000235:genetics; D004285:Dogs / Q000235:genetics* / Q000276:immunology; D005434:Flow Cytometry / Q000662:veterinary; D015870:Gene Expression / Q000235:genetics; D015151:Immunoblotting / Q000662:veterinary; D007421:Intestine, Small / Q000737:chemistry; D015448:Leukemia, B-Cell / Q000235:genetics / Q000662:veterinary; D008214:Lymphocytes / Q000737:chemistry; D016393:Lymphoma, B-Cell / Q000235:genetics / Q000662:veterinary; D008969:Molecular Sequence Data; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary; D054388:Receptors, CCR / Q000032:analysis / Q000235:genetics*; D016415:Sequence Alignment; D014018:Tissue Distribution / Q000235:genetics
C119309:CC chemokine receptor 9; D018076:DNA, Complementary; D054388:Receptors, CCR