title: The lactoferrin receptor may mediate the reduction of eosinophils in the duodenum of pigs consuming milk containing recombinant human lactoferrin.
abstract: Lactoferrin is part of the immune system and multiple tissues including the gastrointestinal (GI) tract, liver, and lung contain receptors for lactoferrin. Lactoferrin has many functions, including antimicrobial, immunomodulatory, and iron binding. Additionally, lactoferrin inhibits the migration of eosinophils, which are constitutively present in the GI tract, and increase during inflammation. Lactoferrin suppresses eosinophil infiltration into the lungs and eosinophil migration in -vitro. Healthy pigs have a large population of eosinophils in their small intestine and like humans, pigs have small intestinal lactoferrin receptors (LFR); thus, pigs were chosen to investigate the effects of consumption of milk containing recombinant human lactoferrin (rhLF-milk) on small intestinal eosinophils and expression of eosinophilic cytokines. In addition, LFR localization was analyzed in duodenum and circulating eosinophils to determine if the LFR could play a role in lactoferrin's ability to inhibit eosinophil migration. In the duodenum there were significantly fewer eosinophils/unit area in pigs fed rhLF-milk compared to pigs fed control milk (p = 0.025); this was not seen in the ileum (p = 0.669). In the duodenum, no differences were observed in expression of the LFR, or any eosinophil migratory cytokines, and the amount of LFR protein was not different (p = 0.386). Immunohistochemistry (IHC) showed that within the duodenum the LFR localized on the brush border of villi, crypts, and within the lamina propria. Circulating eosinophils also contained LFRs, which may be a mechanism allowing lactoferrin to directly inhibit eosinophil migration.
authors.affiliation: Department of Animal Science, University of California, Davis, CA, USA, ccooper@ucdavis.edu.
authors.forename: Caitlin
authors.initials: C
authors.lastname: Cooper
authors.forename: Eric
authors.initials: E
authors.lastname: Nonnecke
authors.forename: Bo
authors.initials: B
authors.lastname: Lönnerdal
authors.forename: James
authors.initials: J
authors.lastname: Murray
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D002417:Cattle; D002465:Cell Movement / Q000276:immunology; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D004386:Duodenum / Q000166:cytology / Q000276:immunology*; D004804:Eosinophils / Q000166:cytology / Q000276:immunology*; D015870:Gene Expression; D006801:Humans; D007781:Lactoferrin / Q000008:administration & dosage* / Q000235:genetics / Q000378:metabolism; D008297:Male; D008892:Milk / Q000276:immunology*; D011956:Receptors, Cell Surface / Q000378:metabolism*; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000235:genetics; D034421:Sus scrofa
chemical_list: D016207:Cytokines; D011956:Receptors, Cell Surface; D011994:Recombinant Proteins; C038340:lactoferrin receptors; D007781:Lactoferrin