■γδ(γδ)T细胞是猪中的主要免疫细胞亚群。在幼猪中大约50%的循环T细胞是γδT细胞,在成年母猪中高达30%。尽管如此丰富,猪γδT细胞的功能大多不明确。在人类和老鼠中,激活的γδT细胞对多种应激表现出广泛的先天细胞毒活性,感染,和癌细胞通过死亡受体/配体依赖性和穿孔素/颗粒酶依赖性途径。然而,到目前为止,目前尚不清楚猪γδT细胞是否具有细胞毒性功能。
■在这项研究中,我们对从血液中分离的猪γδT细胞进行了全面的表型表征,肺,和鼻粘膜。为了进一步分析γδT细胞的细胞溶解潜力,使用纯化的γδT细胞作为效应细胞和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,仅CD2γδT细胞表达细胞毒性标志物(CD16,NKp46,穿孔素),在从肺和鼻粘膜分离的γδT细胞中,穿孔素和NKp46表达更高。此外,我们发现γδT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性功能。然而,猪γδT细胞似乎没有特异性靶向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。
■猪γδT细胞表达细胞毒性标志物,并可在体外表现出细胞毒性活性。猪γδT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。
UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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.