Nitric Oxide Mediates Insect Cellular Immunity via Phospholipase A < sub > 2 < /sub > Activation
This study focuses on the cross-talk between NO and eicosanoid signaling in our model insect,Spodoptera exigua. Bacterial injection increased NO concentrations in the larval hemocytes and fat body, and RNA interference (RNAi) of theS. exigua NO synthase (NOS) gene suppressed NO concentrations. RNAi treatment also led to a significant reduction in hemocyte nodulation following bacterial injection.Similar RNAi treatments led to significantly reduced PLA2 activities in the hemocytes and fat body compared to control larvae. Injection ofL-NAME also prevented the induction of PLA2 activity following bacterial challenge. An injec...
Source: Journal of Innate Immunity - October 16, 2017 Category: Allergy & Immunology Source Type: research
Immunoregulation of Neutrophil Extracellular Trap Formation by Endothelial-Derived p33 (gC1q Receptor)
In this study, we show that p33 is an endothelial-derived protein that has the ability to annul NET formation. We found that the expression of human p33 is up-regulated in endothelial cells upon infections withStreptococcus pyogenes bacteria. Using tissue biopsies from a patient with streptococcal necrotising fasciitis, we monitored co-localisation of p33 with MPO. Further in vitro studies revealed that p33 is able to block the formation of DAMP-induced NET formation by inhibiting the enzymatic activity of MPO. Additionally, mice challenged withS. pyogenes bacteria demonstrated diminished MPO activity when treated with p33...
Source: Journal of Innate Immunity - October 16, 2017 Category: Allergy & Immunology Source Type: research
Macrophage Extracellular Traps: A Scoping Review
Tissue macrophages are derived from either circulating blood monocytes that originate in the bone marrow, or embryonic precursors that establish residence in tissues and are maintained independent of bone marrow progenitors. Macrophages perform diverse functions including tissue repair, the maintenance of homeostasis, and immune regulation. Recent studies have demonstrated that macrophages produce extracellular traps (ETs). ETs are an immune response by which a cell undergoes “ETosis” to release net-like material, with strands composed of cellular DNA that is studded with histones and cellular proteins. ETs are thought...
Source: Journal of Innate Immunity - October 6, 2017 Category: Allergy & Immunology Source Type: research
Innate Immunity Protein Tag7 Induces 3 Distinct Populations of Cytotoxic Cells That Use Different Mechanisms to Exhibit Their Antitumor Activity on Human Leukocyte Antigen-Deficient Cancer Cells
In this study, we found that the treatment of human peripheral blood lymphocytes with the innate immunity protein Tag7 (PGRP-S, PGLYRP1) induces differentiation of the populations of NK (natural killer) cells and CD8+ and CD4+ T lymphocytes that are cytotoxic for human leukocyte antigen-negative tumor cells. These populations employ different mechanisms of tumor cell lysis (based on the release of granzymes in the case of NK cells and on the FasL-Fas interaction in the case of CD8+ and CD4+ T lymphocytes) and induce different death pathways (apoptosis or necroptosis) in tumor cells. An analysis of genes activated in leukoc...
Source: Journal of Innate Immunity - October 4, 2017 Category: Allergy & Immunology Source Type: research
Galectin-9 Produced by Intestinal Epithelial Cells Enhances Aldehyde Dehydrogenase Activity in Dendritic Cells in a PI3K- and p38-Dependent Manner
Intestinal epithelial cells (IEC) drive regulatory T cell (Treg) responses by promoting the differentiation of aldehyde dehydrogenase (ALDH)-expressing CD103+ dendritic cells (DC). Apical stimulation of TLR9 by CpG DNA on IEC supports galectin-9 expression by IEC, which is promoted by short-chain galacto-oligosaccharides and long-chain fructo-oligosaccharides (GF). While galectin-9 can induce the maturation of monocyte-derived DC (moDC), the contribution of galectin-9 on the induction of ALDH activity in DC is not known. To this end, DC were stimulated with galectin-9, and ALDH activity and the expression of CD103 were ass...
Source: Journal of Innate Immunity - September 8, 2017 Category: Allergy & Immunology Source Type: research
