Skip to main content
ARS Home » Plains Area » College Station, Texas » Southern Plains Agricultural Research Center » Food and Feed Safety Research » Research » Publications at this Location » Publication #379553
Research Project: Identification of the Ecological Niches and Development of Intervention Strategies to Reduce Pathogenic Foodborne Pathogens in Poultry

Location: Food and Feed Safety Research

Title: Granulocytes

Author
item Kogut, Michael - Mike

Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 1/22/2021
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Heterophils are the most numerous granulocytic leukocytes in the peripheral blood of poultry characterized by a multilobes nucleus and intracellular granules. As effector cells, heterophils rapidly migrate from the peripheral blood to the site of infection/injury. Heterophils are specialized white blood cells which are primary components of innate immunity. Considered the avian equivalent to mammalian neutrophils, heterophils respond to similar microbial stimuli, exhibit chemotaxis, phagocytize microbial pathogens, produce cytokines, and metabolites to maintain immune homeostasis. Heterophils are involved in all roles played by the innate immune response ranging from inflammation and defense against pathogens to wound healing and tissue remodeling. As the 'first responders' to bacterial infection and tissue injury, heterophils initiate the acute inflammatory response initially by recognizing and killing bacterial pathogens through the release of an arsenal of antimicrobial mediators including oxygen radicals, proteolytic enzymes, and antimicrobial peptides (AMPs) and then initiate injury repair by the activation of intracellular cell signaling cascade resulting in the expression of effector molecules including chemokines and cytokines. Heterophils initiate the innate immune response using a number of receptors including receptors for opsonized particles, nonspecific glycosylated receptors that recognize lectins on target microbes, and receptors that recognize conserved molecular signatures shared and produced by a large group of microbes called microbial associated membrane patterns (MAMPs). Heterophil recognition of these MAMPs is mediated by transmembrane or cytoplasmic proteins called pattern recognition receptors (PRR). Innate immune recognition of MAMPs initiates a signal transduction cascade that leads to the transcription of immune response genes and the production of various effector molecules.