title: Neutrophil function of neonatal foals is enhanced in vitro by CpG oligodeoxynucleotide stimulation.
abstract: Rhodococcus equi is an intracellular bacterium that causes pneumonia in foals and immunocompromised adult horses. Evidence exists that foals become infected with R. equi early in life, a period when innate immune responses are critically important for protection against infection. Neutrophils are innate immune cells that play a key role in defense against this bacterium. Enhancing neutrophil function during early life could thus help to protect foals against R. equi infection. The objective of our study was to determine whether in vitro incubation with the TLR9 agonist CpG 2142 would enhance degranulation and gene expression of cytokines and Toll-like receptor 9 (TLR9) by neutrophils collected from foals at 2, 14, and 56 days of life, and to determine whether these stimulated responses varied among ages. Neutrophil degranulation was enhanced at all ages by in vitro stimulation with either CpG alone, R. equi alone, or in combination with either R. equi or N-formyl-methionyl-leucyl-phenylalanine (fMLP) (P<0.05), but not by in vitro stimulation with fMLP alone. There were no significant differences among ages in CpG-induced cytokine expression, except for IL-12p40, which was induced more at 56 days of age than on days 2 or 14. Collapsing data across ages, CpG 2142 significantly (P<0.05) increased IL-6 and IL-17 mRNA expression. We concluded that in vitro stimulation of foal neutrophils with CpG enhances their function by promoting degranulation and inducing mRNA expression of IL-6 and IL-17, regardless of age.
authors.affiliation: Department of Large Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843-4475, USA.
authors.forename: Angela I
authors.initials: AI
authors.lastname: Bordin
authors.forename: Mei
authors.initials: M
authors.lastname: Liu
authors.forename: Jessica R
authors.initials: JR
authors.lastname: Nerren
authors.forename: Stephanie L
authors.initials: SL
authors.lastname: Buntain
authors.forename: Courtney N
authors.initials: CN
authors.lastname: Brake
authors.forename: Michael H
authors.initials: MH
authors.lastname: Kogut
authors.forename: Noah D
authors.initials: ND
authors.lastname: Cohen
mesh_terms: D000193:Actinomycetales Infections / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary; D000818:Animals; D000831:Animals, Newborn / Q000276:immunology; D016207:Cytokines / Q000096:biosynthesis; D004359:Drug Therapy, Combination; D006734:Horse Diseases / Q000276:immunology / Q000517:prevention & control; D006736:Horses / Q000276:immunology; D007113:Immunity, Innate / Q000187:drug effects / Q000276:immunology; D020381:Interleukin-17 / Q000096:biosynthesis; D015850:Interleukin-6 / Q000096:biosynthesis; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000008:administration & dosage / Q000627:therapeutic use; D009504:Neutrophils / Q000187:drug effects / Q000276:immunology*; D009838:Oligodeoxyribonucleotides / Q000008:administration & dosage / Q000627:therapeutic use*; D016929:Rhodococcus equi / Q000276:immunology; D051217:Toll-Like Receptor 9 / Q000096:biosynthesis
chemical_list: C408982:CPG-oligonucleotide; D016207:Cytokines; D020381:Interleukin-17; D015850:Interleukin-6; D009838:Oligodeoxyribonucleotides; D051217:Toll-Like Receptor 9; D009240:N-Formylmethionine Leucyl-Phenylalanine