|Kogut, Michael - Mike|
Submitted to: Veterinary Immunology and Immunopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/18/2008
Publication Date: 1/10/2009
Citation: Nerren, J.R., Kogut, M.H. 2009. The selective Dectin-1 agonist, curdlan, induces an oxidative burst response in chicken heterophils and peripheral blood mononuclear cells. Veterinary Immunology and Immunopathology. 127:162-166.
Interpretive Summary: Host immune cells recognize unique components of bacteria and fungi using structures located on their surface called pattern recognition receptors. These pattern recognition receptors then send signals to the brain of the cell, the nucleus, which causes the cell to respond in a defensive manner. One of these pattern recognition receptors is called Dectin-1. This receptor has been shown to play an important role in the immune system's defense against bacteria and fungi. To date, however, this receptor has only been documented in mammals. In the present study, immune cells from chickens were stimulated with a unique component from bacteria, curdlan, that Dectin-1 recognizes. Following this stimulation, the immune cells responded by undergoing a reaction called oxidative burst, which results in the production of chemicals that kill bacteria and fungi. When the immune cells were pretreated with laminarin, a chemical that specifically blocks Dectin-1, the oxidative burst reaction was significantly reduced. These data provide evidence that chicken cells possess the critical Dectin-1 receptor on their cells.
Technical Abstract: A critical component of host innate immunity is recognition of pathogen-associated molecular patterns (PAMPs) by pattern recognition receptors (PRRs). Dectin-1 is the primary PRR for exogenous beta-glucan, a component of fungal and bacterial cell walls. A previous study conducted in our laboratory demonstrated that administration of beta-glucan as a feed additive resulted in increased innate immune function of neonatal chickens, suggesting that chickens possess a Dectin-1-like beta-glucan receptor. In the present study, we demonstrated that heterophils and peripheral blood mononuclear cells (PBMCs) from day-old chicks had a significant increase in the generation of reactive oxygen species (ROS) following stimulation with the Dectin-1 specific agonist, curdlan. Pre-treatment of heterophils and PBMCs with laminarin, a beta-glucan receptor blocking agent and specific inhibitor of Dectin-1 activity significantly reduced the curdlan-induced ROS production. Together these data provide evidence for the first time of the presence of a functional Dectin-1-like beta-glucan receptor in chicken heterophils and PBMCs.