■代谢性肝病,包括酒精和非酒精性脂肪性肝病(ALD/NAFLD),以炎症和预防感染的能力下降为特征。患有严重酒精相关肝炎(sAH)的患者在接受类固醇治疗时特别容易感染。了解这些反应的免疫机制对于管理代谢性肝病患者的治疗至关重要。细胞毒性NK细胞和CD8T细胞,使用溶细胞颗粒,通过杀死感染的细胞发挥重要的免疫作用,包括单核细胞。然而,sAH患者的NK细胞功能失调,不能杀死靶细胞,尽管机制未知。
■我们使用单细胞RNA-seq(scRNA-seq)(n=4)和多面板细胞内流式细胞术(所有患者组n=7-8)对从sAH患者和健康对照(HC)分离的PBMC进行了探索性研究。
■ScRNA-seq显示,与健康对照相比,sAH患者中激活单核细胞的细胞毒性细胞识别所需的NK细胞和CD8T细胞中的受体下调。颗粒溶素是NK细胞和效应CD8T细胞中最下调的基因。在来自HC的NK细胞中,颗粒溶素的表达,穿孔素,颗粒酶A和B高度相关;然而,在SAH,这些基因失去了协调表达,指示功能失调的细胞溶解颗粒形成。最后,从sAH开始,NK细胞中溶细胞颗粒蛋白的表达降低,表明细胞溶解颗粒减少。
■一起,这些结果表明,来自sAH的PBMC中细胞毒性细胞功能的丧失,这可能导致与其他免疫细胞的交流能力下降,如单核细胞,防止被感染的细胞被杀死,从而增加感染的风险。
UNASSIGNED: Metabolic liver diseases, including alcohol- and non-alcoholic fatty liver diseases (ALD/NAFLD), are characterized by inflammation and decreased ability to prevent infections. Patients with severe alcohol-associated hepatitis (sAH) are particularly susceptible to infections while undergoing treatment with steroids. Understanding the immunological mechanisms for these responses is critical to managing the treatment of patients with metabolic liver diseases. Cytotoxic NK cells and CD8 T cells, using cytolytic granules, serve an important immunological role by killing infected cells, including monocytes. However, patients with sAH have dysfunctional NK cells, which cannot kill target cells, though the mechanism is unknown.
UNASSIGNED: We performed an exploratory study using single-cell RNA-seq (scRNA-seq) (n = 4) and multi-panel intracellular flow cytometry (n = 7-8 for all patient groups) on PBMCs isolated from patients with sAH and healthy controls (HC).
UNASSIGNED: ScRNA-seq revealed receptors in NK cells and CD8 T cells required for cytotoxic cell recognition of activated monocytes were downregulated in patients with sAH compared to healthy controls. Granulysin was the most downregulated gene in both NK cells and effector CD8 T cells. In NK cells from HC, expression of granulysin, perforin, and granzymes A and B was highly correlated; however, in sAH, these genes lost coordinate expression, indicative of dysfunctional cytolytic granule formation. Finally, the expression of cytolytic granule proteins in NK cells was decreased from sAH, indicating reduced cytolytic granules.
UNASSIGNED: Together, these results suggest a loss of cytotoxic cell function in PBMCs from sAH that may contribute to a decreased ability to communicate with other immune cells, such as monocytes, and prevent the killing of infected cells, thus increasing the risk of infection.