title: Comparative innate immune interactions of human and bovine secretory IgA with pathogenic and non-pathogenic bacteria.
abstract: Secretory IgA (SIgA) from milk contributes to early colonization and maintenance of commensal/symbiotic bacteria in the gut, as well as providing defence against pathogens. SIgA binds bacteria using specific antigenic sites or non-specifically via its glycans attached to α-heavy-chain and secretory component. In our study, we tested the hypothesis that human and bovine SIgA have similar innate-binding activity for bacteria. SIgAs, isolated from human and bovine milk, were incubated with a selection of commensal, pathogenic and probiotic bacteria. Using flow cytometry, we measured numbers of bacteria binding SIgA and their level of SIgA binding. The percentage of bacteria bound by human and bovine SIgA varied from 30 to 90% depending on bacterial species and strains, but was remarkably consistent between human and bovine SIgA. The level of SIgA binding per bacterial cell was lower for those bacteria that had a higher percentage of SIgA-bound bacteria, and higher for those bacteria that had lower percentage of SIgA-bound bacteria. Overall, human and bovine SIgA interacted with bacteria in a comparable way. This contributes to longer term research about the potential benefits of bovine SIgA for human consumers.
authors.affiliation: Dairy Foods Team, Food & Bio-Based Products Group, AgResearch Ruakura, Hamilton, New Zealand. Electronic address: ali.hodgkinson@agresearch.co.nz.
authors.forename: Alison J
authors.initials: AJ
authors.lastname: Hodgkinson
authors.affiliation: Dairy Foods Team, Food & Bio-Based Products Group, AgResearch Ruakura, Hamilton, New Zealand.
authors.forename: Julie
authors.initials: J
authors.lastname: Cakebread
authors.affiliation: Dairy Foods Team, Food & Bio-Based Products Group, AgResearch Ruakura, Hamilton, New Zealand.
authors.forename: Megan
authors.initials: M
authors.lastname: Callaghan
authors.affiliation: Dairy Foods Team, Food & Bio-Based Products Group, AgResearch Ruakura, Hamilton, New Zealand.
authors.forename: Paul
authors.initials: P
authors.lastname: Harris
authors.affiliation: Dairy Foods Team, Food & Bio-Based Products Group, AgResearch Ruakura, Hamilton, New Zealand.
authors.forename: Rachel
authors.initials: R
authors.lastname: Brunt
authors.affiliation: Food Nutrition & Health Team, Food & Bio-Based Products Group, AgResearch Grasslands, Palmerston North, New Zealand; Riddet Institute, Massey University, Palmerston North 4442, New Zealand.
authors.forename: Rachel C
authors.initials: RC
authors.lastname: Anderson
authors.affiliation: Food Nutrition & Health Team, Food & Bio-Based Products Group, AgResearch Grasslands, Palmerston North, New Zealand.
authors.forename: Kelly M
authors.initials: KM
authors.lastname: Armstrong
authors.affiliation: Dairy Foods Team, Food & Bio-Based Products Group, AgResearch Ruakura, Hamilton, New Zealand.
authors.forename: Brendan
authors.initials: B
authors.lastname: Haigh
mesh_terms: D000818:Animals; D001419:Bacteria / Q000276:immunology / Q000378:metabolism*; D002417:Cattle; D054884:Host-Pathogen Interactions; D006801:Humans; D007113:Immunity, Innate; D007071:Immunoglobulin A, Secretory / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D008892:Milk / Q000378:metabolism*; D011134:Polysaccharides / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D011485:Protein Binding; D013045:Species Specificity; D013559:Symbiosis
chemical_list: D007071:Immunoglobulin A, Secretory; D011134:Polysaccharides
keywords: Bacteria; Bacteria binding; Bovine IgA; Human IgA; Secretory IgA