title: Evidence for the existence of regulatory and effector B cell populations in Peyer's patches of sheep.
abstract: IL-10 secreting CD21(+) B cells exist in sheep Peyer's patches (PP). It's not known however, whether all PP B cells are regulatory or whether an effector population also exists in this tissue. To further characterize the subpopulations of B cells in PP's, highly purified B cells were negatively sorted from jejunal PP and fractionated according to co-expression of CD72(+)CD21(+)or CD72(+)CD21(-) molecules and then stimulated with the TLR9-agonist, CpG ODN. IL-10, IL-12, IFN-γ, and IgM production were then assayed. We observed that only highly purified CD72(+)CD21(+) B cells spontaneously secreted high levels of IL-10, but they did not produce any IL-12, IFN-γ or IgM suggesting that this cell population contains regulatory B cells. In contrast, CD72(+)CD21(-) B cells did not secrete IL-10, but secreted IL-12, IFN-γ, and IgM, suggesting they include effector cells. In addition, B cells expressing surface IgA, IgM and IgG1 all secreted similar levels of IL-10. We further confirmed that only B cells produce IL-10, while other cells in the PP including DCs and T cells do not. Our investigations may provide evidence for the existence of two sub-populations in sheep PP; IL-10 secreting regulatory (CD72(+)CD21(+)) cells, and IL-12/IFN-γ/IgM-secreting effector (CD72(+)CD21(-)) cells.
authors.affiliation: Vaccinology & Immunotherapeutic program, School of Public Health, Saskatoon, Saskatchewan, Canada; VIDO/International Vaccine Centre, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Jimbo
authors.affiliation: Vaccinology & Immunotherapeutic program, School of Public Health, Saskatoon, Saskatchewan, Canada; VIDO/International Vaccine Centre, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
authors.forename: P J
authors.initials: PJ
authors.lastname: Griebel
authors.affiliation: VIDO/International Vaccine Centre, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
authors.forename: H
authors.initials: H
authors.lastname: Townsend
authors.affiliation: University of Alberta, Edmonton, Alberta, Canada.
authors.forename: L A
authors.initials: LA
authors.lastname: Babiuk
authors.affiliation: Vaccinology & Immunotherapeutic program, School of Public Health, Saskatoon, Saskatchewan, Canada; VIDO/International Vaccine Centre, University of Saskatchewan, Saskatoon, Saskatchewan, Canada. Electronic address: George.mutwiri@usask.ca.
authors.forename: G
authors.initials: G
authors.lastname: Mutwiri
mesh_terms: D000818:Animals; D000944:Antigens, Differentiation, B-Lymphocyte / Q000378:metabolism; D016175:B-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology*; D060151:B-Lymphocytes, Regulatory / Q000166:cytology / Q000276:immunology*; D005260:Female; D007071:Immunoglobulin A, Secretory / Q000378:metabolism; D007074:Immunoglobulin G / Q000378:metabolism; D007075:Immunoglobulin M / Q000096:biosynthesis; D007371:Interferon-gamma / Q000096:biosynthesis; D016753:Interleukin-10 / Q000096:biosynthesis; D018664:Interleukin-12 / Q000096:biosynthesis; D008297:Male; D010581:Peyer's Patches / Q000166:cytology / Q000276:immunology*; D011947:Receptors, Antigen, B-Cell / Q000378:metabolism; D017464:Receptors, Complement 3d / Q000378:metabolism; D034561:Sheep, Domestic / Q000033:anatomy & histology / Q000276:immunology*
chemical_list: D000944:Antigens, Differentiation, B-Lymphocyte; D007071:Immunoglobulin A, Secretory; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D011947:Receptors, Antigen, B-Cell; D017464:Receptors, Complement 3d; D016753:Interleukin-10; D018664:Interleukin-12; D007371:Interferon-gamma
keywords: B(regs); CpG ODN; Effector B cells; Immune regulation; Peyer’s patches; Regulatory cells; TLR9