title: NCR1+ cells in dogs show phenotypic characteristics of natural killer cells.
abstract: No specific markers for natural killer (NK) cells in dogs have currently been described. NCR1 (NKp46, CD355) has been considered a pan species NK cell marker and is expressed on most or all NK cells in all species investigated except for the pig which has both a NCR1(+) and a NCR1(-) population. In this study peripheral blood mononuclear cells (PBMC) from 14 healthy dogs, 37 dogs with a clinical diagnosis, including a dog diagnosed with LGL leukemia, and tissue samples from 8 dogs were evaluated for NCR1(+) expression by a cross reacting anti bovine NCR1 antibody. CD3(-)NCR1(+) cells were found in the blood of 93 % of healthy dogs and comprised up to 2.5 % of lymphocytes in PBMC. In a selection of healthy dogs, sampling and immunophenotyping were repeated throughout a period of 1 year revealing a substantial variation in the percentage of CD3(-)NCR1(+) over time. Dogs allocated to 8 disease groups had comparable amounts of CD3(-)NCR1(+) cells in PBMC to the healthy individuals. All organs examined including liver, spleen and lymph nodes contained CD3(-)NCR1(+) cells. Circulating CD3(-)NCR1(+) cells were further characterized as CD56(-)GranzymeB(+)CD8(-). A CD3(+)NCR1(+) population was observed in PBMC in 79 % of the healthy dogs examined representing at the most 4.8 % of the lymphocyte population. In canine samples examined for CD56 expression, CD56(+) cells were all CD3(+) and NCR1(-). To our knowledge, this is the first examination of NCR1 expression in the dog. The study shows that this NK cell associated receptor is expressed both on populations of CD3(+) and CD3(-) blood lymphocytes in dogs and the receptor is found on a CD3(+) GranzymeB(+) CD8(+) leukemia. Our results support that CD56 is expressed only on CD3(+) cells in dogs and shows that NCR1 defines a different CD3(+) lymphocyte population than CD56(+)CD3(+) cells in this species. CD3(-)NCR1(+) cells may represent canine NK cells.
authors.affiliation: Department of Food Safety and Infection Biology, Faculty of Veterinary Medicine and Biosciences, Norwegian University of Life Sciences, Oslo, Norway.
authors.forename: Christine
authors.initials: C
authors.lastname: Grøndahl-Rosado
authors.forename: Tina B
authors.initials: TB
authors.lastname: Bønsdorff
authors.forename: Hege C
authors.initials: HC
authors.lastname: Brun-Hansen
authors.forename: Anne K
authors.initials: AK
authors.lastname: Storset
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017252:CD3 Complex / Q000276:immunology; D003429:Cross Reactions / Q000276:immunology; D004283:Dog Diseases / Q000276:immunology / Q000503:physiopathology; D004285:Dogs; D006801:Humans; D016130:Immunophenotyping; D007694:Killer Cells, Natural / Q000276:immunology*; D007938:Leukemia / Q000276:immunology / Q000662:veterinary; D007963:Leukocytes, Mononuclear / Q000276:immunology*; D008099:Liver / Q000166:cytology; D008198:Lymph Nodes / Q000166:cytology; D016131:Lymphocyte Subsets / Q000276:immunology*; D008297:Male; D008969:Molecular Sequence Data; D055627:Natural Cytotoxicity Triggering Receptor 1 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D013154:Spleen / Q000166:cytology
chemical_list: D017252:CD3 Complex; D055627:Natural Cytotoxicity Triggering Receptor 1