Electroporation-mediated delivery of FER gene enhances innate immune response and improves survival in a murine model of pneumonia

Abstract

Previously, we reported that electroporation-mediated (EP) delivery of the FER gene improved survival in a combined trauma-pneumonia model. The mechanism of this protective effect is unknown. In this paper, we performed a pneumonia model in C57/BL6 mice with 500 CFU of Klebsiella pneumoniae. After inoculation, a plasmid encoding human FER was delivered by EP into the lung (PNA/pFER-EP). Survival of FER-treated vs. controls (PNA; PNA/EP-pcDNA) was recorded. In parallel cohorts, bronchial alveolar lavage (BAL) and lung were harvested at 24 and 72 h with markers of infection measured. FER-EP-treated animals reduced bacterial counts and had better 5-day survival compared to controls (80 vs 20 vs 25%; p<0.05). Pre-treatment resulted in 100% survival. With FER, inflammatory monocytes were quickly recruited into BAL. These cells had increased surface expression for Toll-receptor 2 and 4, and increased phagocytic and myeloperoxidase activity at 24 h. Samples from FER electroporated animals had increased phosphorylation of STAT transcription factors, varied gene expression of IL1β, TNFα, Nrf2, Nlrp3, Cxcl2, HSP90 and increased cytokine production of TNF-α, CCL-2, KC, IFN-γ and IL-1RA. In a follow-up experiment, using Methicillin-Resistant Staphylococcus aureus (MRSA) similar bacterial reduction effects were obtained with FER gene delivery. We conclude that FER overexpression improves survival through STAT activation enhancing innate immunity and accelerating bacterial clearance in the lung. This constitutes a novel mechanism of inflammatory regulation with therapeutic potential in the setting of hospital-acquired pneumonia.

TLR3 absence confers increased survival with improved macrophage activity against pneumonia

“…The alveolar macrophage phenotype polarization following pneumonia. Macrophage polarization into M1 or M2 phenotype dictates the nature, duration, and severity of an inflammatory response (4,24,25). WT and TLR3 -/mice were subjected to KP, and RNA was isolated from the BAL macrophages.…”

“…Statistical significance of data between 2 groups was analyzed using 2-tailed, unpaired t test with Welch's correction, and data from more than 2 groups were analyzed using 1-way ANOVA with Tukey's multiple-comparisons test (Graph Pad Prism 8.00) (4). Survival curves (Kaplan-Meier plots) were compared using log-rank tests (25). Fluorescence recovery analysis was done using ImageJ (NIH) (58).…”

Natural genetic variation inDrosophila melanogasterreveals genes associated withCoxiella burnetiiinfection

“…FER expression leads to activation of the DPP-mediated pathway, which has recently been shown to improve survival of Klebsiella pneumoniae through STAT3 when overexpressed ( Murray 2006 ; Dolgachev et al 2018 ; Li et al 2019 ). Coxiella burnetii induces expression of STAT3 and IL-10 during murine infection ( Murray 2006 ; Textoris et al 2010 ; Millar et al 2015 ).…”

Role of the Purinergic P2Y2 Receptor in Pulmonary Hypertension

“…The ATP release by different cell types, which is a part of the vascular tone regulation mechanisms, has another biological function. It participates in the phagocytosis of apoptotic cells and involves inflammatory cells such as monocytes, dendritic, macrophages, eosinophils, and neutrophils in the circulation system via inflammatory P2Y2 sensing [ 60 , 76 , 156 , 157 ]. Thus, ATP release from different apoptotic cells in pulmonary tissues, which is sensed by mast cells, eosinophils, dendritic cells, and other inflammatory cell types, suggests a significant inflammatory clearance role for ATP, UTP, ADP, and P2Y2 receptors in asthma, chronic obstructive pulmonary disease, cystic fibrosis, and other pulmonary diseases [ 30 , 32 , 33 , 35 , 37 , 70 , 73 , 76 , 125 , 128 , 158 , 159 , 160 , 161 , 162 ].…”