title: Polymerization-dependent activation of porcine γδ T-cells by proanthocyanidins.
abstract: Plant-derived proanthocyanidins (PAC) have been promoted as a natural method of improving health and immune function in livestock. It has previously been shown that PAC are effective agonists for activating ruminant γδ T-cells in vitro, however effects on other livestock species are not yet clear. Moreover, the fine structural characteristics of the PAC which contribute to this stimulatory effect have not been elucidated. Here, we demonstrate activation of porcine γδ T-cells by PAC via up-regulation of CD25 (IL-2Rα) and show that 1) activation is dependent on degree of polymerization (DP), with PAC fractions containing polymers with mean DP >6 significantly more effective than fractions with mean DP <6, whilst flavan-3-ol monomers (the constituent monomeric units of PAC) did not induce CD25 expression and 2) both procyanidin and prodelphinidin-type PAC are effective agonists. Furthermore, we show that this effect of PAC is restricted to the γδ T-cell population within porcine peripheral mononuclear cells as significant CD25 up-regulation was not observed in non γδ T-cells, and no activation (via CD80/86 up-regulation) was evident in monocytes. Our results show that dietary PAC may contribute to enhancement of innate immunity in swine via activation of γδ T-cells.
authors.affiliation: Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark. Electronic address: arw@sund.ku.dk.
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Williams
authors.affiliation: Chemistry and Biochemistry Laboratory, School of Agriculture, Policy and Development, University of Reading, Reading, United Kingdom.
authors.forename: Christos
authors.initials: C
authors.lastname: Fryganas
authors.affiliation: Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark.
authors.forename: Kirsten
authors.initials: K
authors.lastname: Reichwald
authors.affiliation: Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark.
authors.forename: Søren
authors.initials: S
authors.lastname: Skov
authors.affiliation: Chemistry and Biochemistry Laboratory, School of Agriculture, Policy and Development, University of Reading, Reading, United Kingdom.
authors.forename: Irene
authors.initials: I
authors.lastname: Mueller-Harvey
authors.affiliation: Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark.
authors.forename: Stig M
authors.initials: SM
authors.lastname: Thamsborg
mesh_terms: D000818:Animals; D009000:Monocytes / Q000276:immunology* / Q000378:metabolism; D058105:Polymerization; D044945:Proanthocyanidins / Q000276:immunology / Q000494:pharmacology*; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000276:immunology* / Q000378:metabolism; D034421:Sus scrofa / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D013601:T-Lymphocytes / Q000378:metabolism*; D015854:Up-Regulation
chemical_list: D044945:Proanthocyanidins; D016692:Receptors, Antigen, T-Cell, gamma-delta
keywords: Activation; Innate immunity; Proanthocyanidins; γδ T-cells