NKp46 defines a subset of bovine leukocytes with natural killer cell characteristics

Abstract

Natural killer (NK) cells have not previously been precisely identified or characterized in cattle or any other ruminant species. We have generated a monoclonal antibody against bovine NKp46, which is expressed exclusively by NK cells in man. NKp46 + cells comprised 1-10% of blood mononuclear cells in cattle, and did not stain with antibodies against CD3, CD4, TCR1, B cell or granulocyte markers. The majority of the NKp46 + cells expressed CD2, and a variable fraction also expressed CD8. The tissue distribution of NKp46 + cells in cattle was compatible with the tissue distribution of NK cells in other species. Bovine NKp46 + cells had typical, large granular lymphocyte morphology, and proliferated vigorously in response to bovine IL-2 for a limited number of cell divisions. IL-2-activated NKp46 + cells killed the bovine kidney cell line MDBK. This cytotoxicity was inhibited by preincubation with antibody against NKp46. In a redirected lysis assay, IL-2-activated NKp46 + cells killed the Fc + R + target cell line P815 after preincubation with antibody against NKp46. Together, these data indicate that bovine NKp46 is an activating receptor and demonstrate the existence of a subset of leukocytes in cattle that, in terms of surface markers, morphology and function, represent NK cells.

Identification of immediate early gene products of bovine herpes virus 1 (BHV-1) as dominant antigens recognized by CD8 T cells in immune cattle

“…The involvement of CD8 T cells was inferred from ablation of cytotoxicity following depletion of CD8 T cells by antibody-and complementmediated lysis. Since CD8 is also known to be expressed on bovine NK cells and gd T cells [36,37], which can exhibit cytotoxic activity, the attribution of the cytotoxicity measured in these studies to classical CD8 T cells remains open to question. Nevertheless, it is possible that CD8 T cells specific for additional antigens, including the glycoproteins, were present at low frequency in our T-cell lines, but were not detected by our screening method.…”

Change in Lymphocyte Subsets of Holstein Calves Caused by Short-term Transportation

“…The CD2 molecule is the receptor for activation on both T cells and NK cells (McNerney & Kumar 2006), although it is not expressed on most WC1+ γδT cells (Davis et al 1996). Storset et al (2004) reported that in cattle, most circulating NK cells are CD2+ and that CD2-cells comprise a low percentage. In this study, only the smaller CD2-NK cell population increased significantly just after transport, as did the total NK cell population.…”

A Review On Nk46 the Immunogenetic Predictive Candidate Gene of Unexpplained Recurrent Miscarrages

“…NKp 46 gene is currently considered the most reliable identifying marker for natural for natural killer cells across species [16]. Natural Killer cells are effector regulatory lymphocytes of the innate immune system that contribute to tumor surveillance hematopoietic allograft rejection, control of microbial infections and pregnancy [17]. They have also been suggested to provide a link between innate and acquired immunity through production of cytokines and interaction with antigen -presenting cells [17].…”

“…Natural Killer cells are effector regulatory lymphocytes of the innate immune system that contribute to tumor surveillance hematopoietic allograft rejection, control of microbial infections and pregnancy [17]. They have also been suggested to provide a link between innate and acquired immunity through production of cytokines and interaction with antigen -presenting cells [17]. Since the NKp 46 gene is thought to be the main natural killer cell activating receptor and also proven to display functional cross talk with other natural cytotoxic receptors and natural killer cell activating receptors, we propose a strong involvement of this gene in the pathogenesis of unexplained recurrent miscarries suggesting it a candidate gene for the condition [18].…”