CD56 is Expressed Exclusively on CD3+ T Lymphocytes in Canine Peripheral Blood.

Abstract

ABSTRACT. CD56+ cells in canine blood leukocytes were characterized by flow-cytometric analysis of peripheral blood of 30 healthy adult beagle-dogs (15 males and 15 non-pregnant females). In 19 of the 30 dogs, anti human CD56 antibody, reacted CD56, which is a neural cell adhesion molecule (N-CAM), is a membrane glycoprotein belonging to the immunoglobulin superfamily [3,8]. CD56 is expressed mainly on natural killer (NK) cell in human peripheral blood and is used as a surface marker of human NK cell [2]. Although the precise functional role of CD56 molecules on human NK cells is not fully understood, CD56 is thought to be involved in cell-attachment of NK cells to the target cells in their cytokilling process [10].In rhesus monkeys, however, peripheral blood NK cells predominantly show CD56 -phenotype [1]. Furthermore, CD56 is expressed on almost all peripheral blood monocytes in cynomolgus monkeys [9,12] and in rhesus monkeys [1]. Therefore, CD56 is not always a specific marker for NK cells in mammals other than humans.An anti human CD56 antibody, Leu-19 (Becton Dickinson, San Jose, California, U.S.A.), cross-reacts with canine leukocytes [14]. However, detailed characteristics of canine CD56 + cells remain unclear. In this study, we clarified the phenotypic characteristics of canine CD56 + cells by flow-cytometric analysis on canine peripheral blood leukocytes.Thirty clinically healthy beagle-dogs (15 males and 15 non-pregnant females) 1.4 to 7.3 years old were used in this study. By vaccination, all dogs were free from rabies virus, canine distemper virus, canine herpesvirus, canine parvovirus, canine parainfluenza virus, and canine adenovirus. Blood was collected from each dog's jugular vein, using sodium citrate as an anti-coagulant. We confirmed that the complete blood counts and the leukocyte differential counts of all blood samples were within normal ranges (data not shown).Direct staining of peripheral blood leukocytes was done as follows. The following pairs of antibodies were reacted with 50 µl samples of blood for 15 min at room temperature: anti human CD56 phycoerythrin conjugated (-PE) antibody (Leu-19; Becton-Dickinson) and anti canine CD3 fluorescein isocyanate conjugated (-FITC) antibody (CA17.2A12; Serotec, Oxford), anti human CD21-PE antibody (B-ly4; Becton-Dickinson) and anti canine CD3-FITC antibody, or isotypic control-FITC antibody (Beckman-Coulter, Fullerton, California, U.S.A.) and isotypic control-PE antibody (Beckman-Coulter). To each of these samples, we added 1.5 ml of Erythrocytes Lysing Buffer (0.83% ammonium chloride, 0.1% potassium hydrocarbonate, and 0.004% EDTA disodium salt in distilled water), and then left the sample for 7 min at room temperature. After centrifugation, the supernatant was removed by aspiration. The pellet was washed twice with wash buffer (phosphate buffered saline containing 0.5% bovine serum albumin, 2 mM EDTA disodium salt, and 0.03% sodium azide) at 4°C. The samples were fixed with 1% paraformaldehyde-phosphate buffered saline, and then subjected to ...

Phenotypic Analysis of Hepatic Lymphocytes from Healthy Dogs

“…The human hepatic NK cells are generally considered to contribute to antiviral, tumoricidal and pathogenic inflammatory responses [13]. However, as any specific surface antigenic molecules have never been identified in the canine NK cells at present [6,8], significant relation of non-T non-B lymphocytes and NK cells in canine liver was not able to be clearly defined in this study.…”

“…After diluting to 1:10 with FCM-buffer, and the samples were immediately acquired by FACS Calibur (Becton-Dickinson, Franklin Lakes, NJ). The lymphocytes were separated from the other cells by gating on the forward scatter versus side scatter dot plot of FACS Calibur [3,5,8]. Fluorescence intensity of 7-AAD in gated lymphocytes was detected at 630 nm (FL-3 on FACS Caliber).…”

“…After being centrifuged, the cell-pellet was washed twice with FCMbuffer at 4°C. This specimen was fixed with 1% paraformaldehyde-phosphate buffered saline and was finally subjected to flow-cytometric analysis as described previously [8]. Phenotypes were analysed on the hepatic lymphocytes obtained by gating on the screen of forward scatter versus side scatter dot plot of FACS Calibur (Fig.…”

Malignant Transformation of T-cell Large Granular Lymphocyte Leukemia in a Dog

“…Ehrlichia infection was ruled out based on serology. Flow cytometric analysis was performed using monoclonal antibodies as described previously [9]. The results indicated that most peripheral blood lymphocytes (PBLs) were of the CD3+8+ phenotype (Figs.…”

Relative Quantification of Canine CD56 mRNA Expression by Real-time Polymerase Chain Reaction Method in Normal Tissues and Activated Lymphocytes

“…CD56 is suggested to be expressed in canine lymphocytes [21]; however, the dynamics of CD56 in peripheral blood is not well understood. The CD56 expression level could be used for a mirror of NK activity if it is supposed to be specifically expressed in canine NK cells.…”