Effect of intravenous immunoglobulin on the function of Treg cells derived from immunosuppressed mice with <i>Pseudomonas aeruginosa</i> pneumonia

<div><p>Aim</p><p>The present study aimed to investigate the effect of intravenous immunoglobulin (IVIG) on regulatory T (Treg) cells derived from immunosuppressed mice with <i>Pseudomonas aeruginosa</i> (PA) pneumonia.</p><p>Methods</p><p>A total of 108 BALB/c mice were randomly divided into the following groups: control group (Control), immunosuppressed group (IS), PA pneumonia group (PA), PA pneumonia in immunosuppressed group (IS + PA), PA pneumonia with IVIG treatment in immunocompetent group (PA + IVIG) and PA pneumonia with IVIG treatment in immunosuppressed group (IS + PA + IVIG). Each group comprised 18 mice. The combined PA pneumonia in immunosuppressed model and the treatment models were established. The mice in each group were sacrificed at 4, 8, and 24 h time points. The general condition and pathological changes in the lung tissues of the mice were monitored. Reverse transcription-polymerase chain reaction was used to detect the forkhead box P3 (<i>FOXP3)</i> mRNA relative expression level in the lung tissues. The enzyme-linked immunosorbent assay was used to detect the serum concentration of active transforming growth factor beta (TGF-β).</p><p>Results</p><p>No inflammatory response were exhibited in the lung tissues of the mice in Control group and IS group, while varying degrees of acute lung injury were revealed in the mice in PA group, IS + PA group, PA + IVIG group and IS + PA + IVIG group. Lung tissue injury was most apparent at the 8 h time point, and it indicated the greatest effect in IS + PA group. Whereas tissue damages were alleviated in PA + IVIG group and IS + PA + IVIG group compared with IS + PA group. In addition, tissue damage lessened in PA + IVIG group compared with PA group and IS + PA + IVIG group. <i>FOXP3</i> mRNA expression levels in the lung tissues and the serum concentration of TGF-β were lower in IS group, PA group, IS + PA group and IS + PA + IVIG group at the 4, 8 and 24 h time points, respectively compared with Control group. <i>FOXP3</i> mRNA expression levels decreased in PA + IVIG group at the 4h time point and TGF-β serum concentrations decreased at the 4 and 8h time points compared with Control group, and subsequently increased.</p><p>Conclusions</p><p>In the immunosuppred model with PA pneumonia, the immune system was greatly compromised. IVIG partially restored the immunosuppressed functions of Treg cells, suppressed the overactivated immune system and ameliorated the development of the disease.</p></div

<i>FOXP3</i> mRNA relative expression level in lung tissue in each group at 4, 8 and 24h.

<p>Six groups were studied: Control group, IS group, PA group, IS + PA group, PA + IVIG group and IS + PA + IVIG group. Immunosuppression was induced on day -5, -3 and -1 by intraperitoneal injection of CYP, PA pneumonia was induced on day 0 and IVIG mediated treatment models were immediately established following PA intervention on day 0. The left lung tissue of the mice was used for testing <i>FOXP3</i> mRNA relative expression by qRT-PCR. qRT-PCR was carried out using a Thermo Fisher PCR kit with FOXP3 and GAPDH primer. <i>FOXP3</i> mRNA relative expression level was calculated by the 2 ^{(- ΔΔ CT)} method. <i>FOXP3</i> mRNA expression levels in lung tissue in six groups at 4, 8 and 24h were shown.</p

Serum concentrations of active TGF-β in each group at 4, 8 and 24h.

<p>Six groups were studied: Control group, IS group, PA group, IS + PA group, PA + IVIG group and IS + PA + IVIG group. Immunosuppression was induced on day -5, -3 and -1 by intraperitoneal injection of CYP, PA pneumonia was induced on day 0 and IVIG mediated treatment models were immediately established following PA intervention on day 0. Serum samples were heated in a water bath at 80°C for 8 min and cooled for 5 min. The serum concentration of active TGF-β was tested by ELISA kit and was determined by comparison with a standard curve. Serum concentrations of active TGF-β in six groups at 4, 8 and 24h were shown.</p

Methods of grouping and modelling.

<p>Methods of grouping and modelling.</p

IL18R1-Related Molecules as Biomarkers for Asthma Severity and Prognostic Markers for Idiopathic Pulmonary Fibrosis

To determine the role of inflammation-related proteins in predicting asthma severity and outcome, 92 inflammation-related proteins were measured in the asthmatic serum using Olink analysis. Different bioinformatics algorithms were developed to cross analyze with the single-cell or transcriptome data sets from the Gene Expression Omnibus database to explore the role of IL18R1 and related genes in asthma and idiopathic pulmonary fibrosis (IPF). Olink identified 52 differentially expressed proteins in asthma. They were strongly linked to the cytokine–cytokine receptor interaction, TNF, and NF-κB signaling pathway. Seven proteins were found in both single-cell RNA and Olink analyses. Among them, IL18R1 was predominantly expressed in mast cells, and the results suggested enhanced communication between mast cells and CD 8+ T cells. IL18R1 was upregulated in serum and induced sputum and bronchoalveolar lavage fluid of patients with uncontrolled or severe asthma. IL18R1 was positively correlated with TNFSF1 and OSM and S100A12. The diagnostic efficacy of these serum IL18R1-related molecules for asthma ranged from 0.839 to 0.921. Moreover, high levels of IL18R1, TNFSF1, OSM, and S100A12 were significantly associated with shorter survival times and worse lung function. IL18R1-related molecules may serve as biomarkers for monitoring uncontrolled or severe asthma and as prognostic markers for IPF