title: In ovo delivery of Toll-like receptor 2 ligand, lipoteichoic acid induces pro-inflammatory mediators reducing post-hatch infectious laryngotracheitis virus infection.
abstract: Toll-like receptor (TLR) ligands are pathogen associated molecular patterns (PAMPs) recognized by the TLRs resulting in induction of host innate immune responses. One of the PAMPs that binds to TLR2 and cluster of differentiation (CD) 14 is lipotechoic acid (LTA), which activates downstream signals culminating in the release of pro-inflammatory cytokines. In this study, we investigated whether in ovo LTA delivery leads to the induction of antiviral responses against post-hatch infectious laryngotracheitis virus (ILTV) infection. We first delivered the LTA into embryo day (ED)18 eggs via in ovo route so that the compound is available at the respiratory mucosa. Then the LTA treated and control ED18 eggs were allowed to hatch and the hatched chicken was infected with ILTV intratracheally on the day of hatch. We found that in ovo delivered LTA reduces ILTV infection post-hatch. We also found that in ovo delivery of LTA significantly increases mRNA expression of pro-inflammatory mediators in pre-hatch embryo lungs as well as mononuclear cell infiltration, predominantly macrophages, in lung of post-hatch chickens. Altogether, the data suggest that in ovo delivered LTA could be used to reduce ILTV infection in newly hatched chickens.
authors.affiliation: Department of Ecosystem and Public Health, Faculty of Veterinary Medicine, University of Calgary, Health Research Innovation Center 2C53, 3330 Hospital Drive NW, Calgary, Canada AB T2N 2Z6.
authors.forename: S
authors.initials: S
authors.lastname: Thapa
authors.affiliation: Department of Pathobiology, University of Guelph, Guelph, Canada.
authors.forename: E
authors.initials: E
authors.lastname: Nagy
authors.affiliation: Department of Ecosystem and Public Health, Faculty of Veterinary Medicine, University of Calgary, Health Research Innovation Center 2C53, 3330 Hospital Drive NW, Calgary, Canada AB T2N 2Z6. Electronic address: faizal.abdulcareem@ucalgary.ca.
authors.forename: M F
authors.initials: MF
authors.lastname: Abdul-Careem
mesh_terms: D000818:Animals; D002645:Chickens; D006566:Herpesviridae Infections / Q000276:immunology / Q000517:prevention & control*; D025921:Iltovirus; D018836:Inflammation Mediators / Q000502:physiology*; D008024:Ligands; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008168:Lung / Q000276:immunology / Q000821:virology; D008264:Macrophages / Q000276:immunology; D010063:Ovum; D015398:Signal Transduction; D013682:Teichoic Acids / Q000494:pharmacology*; D051195:Toll-Like Receptor 2 / Q000502:physiology*
chemical_list: D018836:Inflammation Mediators; D008024:Ligands; D008070:Lipopolysaccharides; D013682:Teichoic Acids; D051195:Toll-Like Receptor 2; C009900:lipoteichoic acid
keywords: In ovo; Infectious laryngotracheitis virus; Lipoteichoic acid; Lung; Toll-like receptor 2