Journal Article

FcεR1-Mediated Mast Cell Reactivity Is Amplified through Prolonged Toll-Like Receptor-Ligand Treatment

Nilsson, Gunnar P., Delin, Ingrid, Adner, Mikael, Saluja, Rohit

2012

Overview

Mast cell-derived mediators mediate several of the pathological features of asthma. Microbial infections induce asthma exacerbations in which the contribution of mast cells remains incomprehensible. In this study we have investigated the characteristic expression pattern of Toll-like receptors (TLRs) 1-9 and the effect of TLR ligand treatment on IgE-receptor mediated mast cell reactivity. For the studies we employed in vitro differentiated connective tissue like mast cells (CTLMC) and mucosal like mast cells (MLMC) from mice. Both phenotypes were treated for 24 h or 96 h with ligands for TLR1/2, TLR2/6, TLR3 and TLR4, before activation with IgE and antigen. Prolonged exposure (96 h) with TLR-ligands promoted mast cell reactivity following IgE-receptor activation. TLR4 activation with LPS generated the most pronounced effect, with an enhanced degranulation and secretion of leukotrienes, cytokines and chemokines, in both CTLMC and MLMC. The effect of LPS was mediated through a Myd88-dependent pathway and the increased effect involved JNK-dependent pathway. We find that prolonged exposure of mast cells to pathogens/TLR-ligands modulates their effector responses by priming them for increased release of several inflammatory mediators when subsequently activated by IgE-receptors. These data suggest that infections might exaggerate the severity of allergic reactions such as in asthma, by enhancing mediator release from mast cells.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Activation / Airway management / Allergic reactions / Allergies / Animals / Antigens / Asthma / Bacterial infections / Biology / Blotting, Western / Cell activation / Cells, Cultured / Chemokines / Chemokines - metabolism / Connective tissues / Cytokines / Cytokines - metabolism / Degranulation / Environmental health / Exposure / Gene expression / Histamine / Hypersensitivity / Immune system / Immunoglobulin E / Immunology / Infections / Inflammation / JNK protein / Leukotrienes / Leukotrienes - metabolism / Ligands / Lipopolysaccharides / Lipopolysaccharides - pharmacology / Mast cells / Mast Cells - drug effects / Mast Cells - metabolism / Medicine / Mice / Microorganisms / Mucosa / MyD88 protein / Priming / Proteins / Reactivity / Real-Time Polymerase Chain Reaction / Receptor mechanisms / Receptors / Receptors, IgE - metabolism / Studies / TLR1 protein / TLR2 protein / TLR3 protein / TLR4 protein / Toll-like receptors / Toll-Like Receptors - agonists / Viral infections