title: Identification of a lineage negative cell population in bovine peripheral blood with the ability to mount a strong type I interferon response.
abstract: Lineage negative dendritic cells, or natural interferon-producing cells (NIPC), also referred to as plasmacytoid dendritic cells (pDC) constitute a small population of leukocytes secreting high levels of type I interferon (IFNα/β) in response to certain danger signals. Here, we provide initial data towards the identification of so far uncharacterised circulating bovine pDC like cells. A lineage negative cell population (LIN(-) cells) was isolated from PBMC which showed characteristics similar to that of pDC in other species. Isolated LIN(-) cells presented lymphoid morphology with a semi-crescent nucleus, extensive ER and Golgi network; indicative of pDC. In addition phenotypic analysis of LIN(-) cells described them as distinct from other bovine DC subsets; expressing both lymphoid and myeloid surface markers. LIN(-) cells did not express lineage specific markers, but were MHC class II(+), CD45RO(+), CD80/86(+), CD6(+), WC1(+), CD26(+) and expressed the myeloid markers CD205, CD172a and CD11a. In keeping with pDC, LIN(-) cells express TLR7 mRNA transcripts; however, in a resting state do not express TLR8 or TLR9. Functionally, LIN(-) cells, but not PBMC, monocytes and monocyte derived DC produce large amounts of IFNα/β in response to different CpG oligonucleotides. Taken together, we present data suggesting that an enriched circulating population of bovine LIN(-) cells are uniquely capable of producing IFNα/β in response to CpG oligonucleotides and thus this population likely contain the functional equivalent of bovine pDC.
authors.affiliation: The Royal Veterinary College, North Mymms, Hatfield, Hertfordshire, UK.
authors.forename: Amanda
authors.initials: A
authors.lastname: Gibson
authors.forename: Suhel
authors.initials: S
authors.lastname: Miah
authors.forename: Philip
authors.initials: P
authors.lastname: Griebel
authors.forename: Joe
authors.initials: J
authors.lastname: Brownlie
authors.forename: Dirk
authors.initials: D
authors.lastname: Werling
mesh_terms: D000818:Animals; D002417:Cattle / Q000097:blood / Q000276:immunology*; D019070:Cell Lineage; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology* / Q000648:ultrastructure; D005434:Flow Cytometry / Q000662:veterinary; D015395:Histocompatibility Antigens Class I / Q000276:immunology; D016130:Immunophenotyping / Q000379:methods / Q000662:veterinary; D007370:Interferon Type I / Q000276:immunology*; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008297:Male; D046529:Microscopy, Electron, Transmission / Q000662:veterinary; D009838:Oligodeoxyribonucleotides / Q000494:pharmacology; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D051199:Toll-Like Receptor 7 / Q000235:genetics / Q000276:immunology
chemical_list: C408982:CPG-oligonucleotide; D015395:Histocompatibility Antigens Class I; D007370:Interferon Type I; D009838:Oligodeoxyribonucleotides; D012333:RNA, Messenger; C495348:TLR7 protein, human; D051199:Toll-Like Receptor 7