Cattle, sheep, and goats are the only species outside primates known to have an expanded and diversified family of killer immunoglobulin-like receptors (KIR). Primate KIR are expressed on the surface of NK and T cells and bind MHC-I to control activation. However, the surface expression, ligands and function of bovid KIR remain unknown. Cattle botaKIR2DL1 is the only functional KIR of the same DL-lineage as the expanded KIR in primates and we examined if leukocyte expression patterns were consistent with human. We raised a specific mouse anti-botaKIR2DL1 monoclonal antibody and assessed its utility in flow cytometry, ELISA, and western blot. Unlike primates, cattle DL-lineage KIR (botaKIR2DL1) is present on B cells and monocytes in addition to T cells and low-level expression on NK cells. Expression decreases after in vitro PBMC stimulation with IL-2. This suggests that botaKIR2DL1 has different functions, and potentially ligands, compared to primate KIR.

牛、绵羊和山羊是灵长类动物之外唯一已知拥有扩大且多样化的杀伤性免疫球蛋白样受体 (KIR) 家族的物种。灵长类动物 KIR 在 NK 和 T 细胞表面表达，并结合 MHC-I 来控制激活。然而，牛科KIR的表面表达、配体和功能仍然未知。牛 botaKIR2DL1 是与灵长类动物中扩展的 KIR 具有相同 DL 谱系的唯一功能性 KIR，我们检查了白细胞表达模式是否与人类一致。我们制备了一种特异性小鼠抗 botaKIR2DL1 单克隆抗体，并评估了其在流式细胞术、ELISA 和蛋白质印迹中的效用。与灵长类动物不同，除了 T 细胞外，牛 DL 谱系 KIR (botaKIR2DL1) 还存在于 B 细胞和单核细胞上，并且在 NK 细胞上有低水平表达。用 IL-2 体外刺激 PBMC 后表达降低。这表明与灵长类 KIR 相比，botaKIR2DL1 具有不同的功能和潜在的配体。