Innate Immunity Group, IdiPAZ, La Paz University Hospital, Madrid, Spain; Tumor Immunology Lab, IdiPAZ, La Paz University Hospital, Madrid, Spain; Center for Biomedical Research Network, CIBEres, Spain.
Innate Immunity Group, IdiPAZ, La Paz University Hospital, Madrid, Spain; Tumor Immunology Lab, IdiPAZ, La Paz University Hospital, Madrid, Spain.
J Cyst Fibros. 2019 Sep;18(5):630-635. doi: 10.1016/j.jcf.2018.11.002. Epub 2018 Nov 12.
Cystic fibrosis (CF) is an endotoxin tolerance (ET)-related disease. Given that increased PD-L1 has been reported in ET, its expression and physiological effects on cystic fibrosis monocytes should be studied.
We analyzed the phenotype and ex vivo response of immune system cells in 32 patients with CF, 19 of them colonized by Pseudomonas aeruginosa. An in vitro model was developed of Pseudomonas aeruginosa colonization using purified lipopolysaccharides (LPS) from one of the most prevalent strains in patients with CF (a CF-adapted Pseudomonas aeruginosa ST395 clone). Changes in the immune response, including cytokine production and T-lymphocyte proliferation, as well as expression of PD-L1, were evaluated.
PD-L1 was overexpressed in the monocytes of patients with CF compared with healthy volunteers, and levels of this immune checkpoint were associated with Pseudomonas aeruginosa colonization. In addition, patients with Pseudomonas aeruginosa colonization showed a patent ET status, including poor inflammatory response, reduced HLA-DR expression and T-lymphocyte proliferation impairment. PD-L1/PD-1 blocking assays reverted the impaired adaptive response. Ultimately, monocytes from healthy volunteers cultured in the presence of the clinically relevant strain of Pseudomonas aeruginosa or serum collected from patients with CF colonized by Pseudomonas aeruginosa reproduced the previous observed features.
Pseudomonas aeruginosa colonization in patients with CF was associated with PD-L1 overexpression and impaired T cell response, and LPS from this pathogen induced the observed phenotype. Our findings open new avenues for the use of anti-PD-1/PD-L1 immunotherapy in patients with CF who are colonized by Pseudomonas aeruginosa.
囊性纤维化（CF）是一种内毒素耐受（ET）相关疾病。鉴于 ET 中 PD-L1 表达增加，应研究其在囊性纤维化单核细胞中的表达及其生理作用。
我们分析了 32 例 CF 患者（其中 19 例定植了铜绿假单胞菌）的免疫系统细胞表型和体外反应。使用从 CF 患者中最常见菌株之一（CF 适应的铜绿假单胞菌 ST395 克隆）分离的纯化脂多糖（LPS）建立了铜绿假单胞菌定植的体外模型。评估了免疫反应的变化，包括细胞因子产生和 T 淋巴细胞增殖以及 PD-L1 的表达。
与健康志愿者相比，CF 患者的单核细胞中 PD-L1 过度表达，并且这种免疫检查点的水平与铜绿假单胞菌定植有关。此外，铜绿假单胞菌定植的患者表现出明显的 ET 状态，包括炎症反应差、HLA-DR 表达降低和 T 淋巴细胞增殖受损。PD-L1/PD-1 阻断测定可逆转受损的适应性反应。最终，在存在临床相关铜绿假单胞菌菌株的情况下培养的健康志愿者的单核细胞或从铜绿假单胞菌定植的 CF 患者采集的血清再现了之前观察到的特征。
CF 患者铜绿假单胞菌定植与 PD-L1 过度表达和 T 细胞反应受损有关，并且来自该病原体的 LPS 诱导了观察到的表型。我们的发现为 CF 患者使用抗 PD-1/PD-L1 免疫疗法开辟了新途径，这些患者定植了铜绿假单胞菌。
