γ-δ (γδ) T 细胞是猪的主要免疫细胞亚群。幼猪中大约 50% 的循环 T 细胞是 γδ T 细胞，成年母猪中这一比例高达 30%。尽管数量如此丰富，但猪 γδ T 细胞的功能大多尚未确定。在人和小鼠中，活化的 γδ T 细胞通过死亡受体/配体依赖性和穿孔素/颗粒酶依赖性途径，对多种应激、感染和癌细胞表现出广泛的先天细胞毒活性。然而，到目前为止，猪γδT细胞是否具有执行细胞毒功能的能力尚不清楚。在本研究中，我们对从血液、肺和鼻粘膜中分离的猪γδT细胞进行了全面的表型表征。为了进一步分析 γδ T 细胞的溶细胞潜力，使用纯化的 γδ T 细胞作为效应细胞，病毒暴露或模拟处理的原代猪肺泡巨噬细胞作为靶细胞进行体外细胞毒性测定。我们的结果表明，只有 CD2 γδ T 细胞表达细胞毒性标记物（CD16、NKp46、穿孔素），从肺和鼻粘膜分离的 γδ T 细胞中穿孔素和 NKp46 表达较高。此外，我们发现γδ T细胞可以以细胞间接触和脱颗粒依赖性方式表现出细胞毒功能。然而，猪γδ T细胞似乎并没有特异性针对猪繁殖与呼吸综合征病毒或猪甲型流感病毒感染的巨噬细胞，这可能是由于病毒逃逸机制所致。猪γδ T细胞表达细胞毒性标记物，在体外可以表现出细胞毒活性。猪 γδ T 细胞识别靶细胞的具体机制尚不完全清楚，但可能涉及细胞应激信号的检测。版权所有 © 2024 Bettin、Darbellay、van Kessel、Dhar 和 Gerdts。

Gamma-delta (γδ) T cells are a major immune cell subset in pigs. Approximately 50% of circulating T cells are γδ T cells in young pigs and up to 30% in adult sows. Despite this abundance, the functions of porcine γδ T cells are mostly unidentified. In humans and mice, activated γδ T cells exhibit broad innate cytotoxic activity against a wide variety of stressed, infected, and cancerous cells through death receptor/ligand-dependent and perforin/granzyme-dependent pathways. However, so far, it is unknown whether porcine γδ T cells have the ability to perform cytotoxic functions.In this study, we conducted a comprehensive phenotypic characterization of porcine γδ T cells isolated from blood, lung, and nasal mucosa. To further analyze the cytolytic potential of γδ T cells, in vitro cytotoxicity assays were performed using purified γδ T cells as effector cells and virus-exposed or mock-treated primary porcine alveolar macrophages as target cells.Our results show that only CD2+ γδ T cells express cytotoxic markers (CD16, NKp46, perforin) with higher perforin and NKp46 expression in γδ T cells isolated from lung and nasal mucosa. Moreover, we found that γδ T cells can exhibit cytotoxic functions in a cell-cell contact and degranulation-dependent manner. However, porcine γδ T cells did not seem to specifically target Porcine Reproductive and Respiratory Syndrome Virus or swine Influenza A Virus-infected macrophages, which may be due to viral escape mechanisms.Porcine γδ T cells express cytotoxic markers and can exhibit cytotoxic activity in vitro. The specific mechanisms by which porcine γδ T cells recognize target cells are not fully understood but may involve the detection of cellular stress signals.Copyright © 2024 Bettin, Darbellay, van Kessel, Dhar and Gerdts.