Effect of ubiquitin-editing protein A20 on monocytes activity in patients with ventilator-associated pneumonia / 中华急诊医学杂志

ABSTRACT

Objective:To investigate and analyze the effect of ubiquitin-editing protein A20 on monocytes activity in patients with ventilator-associated pneumonia (VAP).Methods:Twenty-four VAP patients (VAP group) and twelve healthy controls (control group) were included from the First Affiliated Hospital of Zhengzhou University between February 2019 and September 2019. Peripheral blood mononuclear cells (PBMCs) and bronchial alveolar lavage fluid (BALF) (both infection site and non-infection site) were collected from VAP patients, while PBMCs were collected from healthy controls. A20 level in CD14 + monocytes were measured. CD14 + monocytes and CD4 + T cells were purified from VAP patients. CD14 + monocytes were transfected by A20 siRNA. Transfected CD14 + monocytes were directly/indirectly co-cultured with autologous CD4 + T cells. The secretion of interferon-γ (IFN-γ) and interleukin-17 (IL-17) by CD4 + T cells was investigated. Transfected CD14 + monocytes were directly/indirectly co-cultured with NCI-H889 cells. Cytotoxicity, and cytokines/granzyme B level, and tumor necrosis factor-related apoptosis inducing ligand (TRAIL)/Fas ligand (FasL) level was assessed. Student t test or SNK-q test was used for comparison. Results:VAP group had elevated percentage of circulating CD14 +A20 + cells than control group [(66.14±19.62)% vs. (52.52±13.71)%, P<0.05], and also had increased A20 mean fluorescence intensity (MFI) than control group [(268.0±72.56) vs. (197.4±60.01), P<0.05]. The percentage of CD14 +A20 + cells in BALF from infection site was higher than from non-infection site in VAP group [(66.14±19.62)% vs. (52.52±13.71)%, P<0.05], while A20 MFI in infection site was also up-regulated compared with non-infection site [(268.0±72.56) vs. (197.4±60.01), P<0.05]. In direct contact co-culture, A20 siRNA transfected CD14 + monocytes, which were purified from peripheral blood and BALF of VAP patients, induced elevated percentage of IFN-γ and IL-17 secreting CD4 + T cells than un-transfection or control siRNA transfection ( P<0.05). However, there were no significant differences of CD4 +IFN-γ + or CD4 +IL-17 + percentages among un-transfection, control siRNA transfection, and A20 siRNA transfection ( P>0.05). A20 siRNA transfected CD14 + monocytes, which were purified from peripheral blood and BALF of VAP patients, induced increased target cell death in both direct and indirect contact co-culture than un-transfection or control siRNA transfection ( P<0.05). Tumor necrosis factor-α, IL-6, granzyme B level and TRAIL MFI was also up-regulated ( P<0.05). There was no remarkable difference of target cell death between direct and indirect contact co-culture ( P>0.05). Conclusions:A20 was increasingly expressed in monocytes of VAP patients, and might dampen the activity of monocytes.