title: Human CD19(+)CD25(high) B regulatory cells suppress proliferation of CD4(+) T cells and enhance Foxp3 and CTLA-4 expression in T-regulatory cells.
abstract: Studies in both animal models and humans have shown a subset of B cells behaving as immuno-regulatory cells, being a source of inhibitory cytokines such as IL-10 and TGF-β. Our aims were to establish the presence of human B regulatory (Breg) cells and to assess their ability to suppress proliferation of CD4(+) T cells and to mediate T regulatory (Treg) cells' properties. For this purpose, human Breg, CD4(+) T and Treg cells were purified using magnetic microbeads. CFSE-labeled CD4(+) T cells were stimulated and cultured alone or with Breg cells. Their proliferative response was determined 72 hours later based on the CFSE staining. In parallel, Treg cells were cultured alone or with Breg cells in different conditions for 24 hours, and then stained and analyzed for Foxp3 and CTLA-4 expression. We found that, the co-culture of Breg cells (defined as CD25(high) CD27(high) CD86(high) CD1d(high) IL-10(high) TGF-β(high)) with autologous stimulated CD4(+) T cells decreased significantly (in a dose-dependent way) the proliferative capacity of CD4(+) T cells. Furthermore, Foxp3 and CTLA-4 expression in Treg cells were enhanced by non-stimulated and further by ODN-CD40L stimulated Breg cells. The regulatory function of Breg cells on Treg cells was mainly dependent on a direct contact between Breg and Treg cells, but was also TGF-β but not IL-10 dependent. In conclusion, human Breg cells decrease the proliferation of CD4(+) T cells and also enhance the expression of Foxp3 and CTLA-4 in Treg cells by cell-to-cell contact.
authors.affiliation: Division of Allergy and Clinical Immunology, Bnai Zion Medical Center, Haifa, Israel.
authors.forename: Aharon
authors.initials: A
authors.lastname: Kessel
authors.forename: Tharwat
authors.initials: T
authors.lastname: Haj
authors.forename: Regina
authors.initials: R
authors.lastname: Peri
authors.forename: Ayelet
authors.initials: A
authors.lastname: Snir
authors.forename: Doron
authors.initials: D
authors.lastname: Melamed
authors.forename: Edmond
authors.initials: E
authors.lastname: Sabo
authors.forename: Elias
authors.initials: E
authors.lastname: Toubi
mesh_terms: D018941:Antigens, CD19 / Q000235:genetics / Q000378:metabolism*; D060151:B-Lymphocytes, Regulatory / Q000166:cytology* / Q000187:drug effects / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology* / Q000276:immunology / Q000378:metabolism; D060908:CTLA-4 Antigen / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D002450:Cell Communication; D049109:Cell Proliferation; D018920:Coculture Techniques; D005452:Fluoresceins; D005456:Fluorescent Dyes; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D005786:Gene Expression Regulation; D006801:Humans; D018189:Immunomagnetic Separation; D016753:Interleukin-10 / Q000276:immunology / Q000494:pharmacology; D053645:Interleukin-2 Receptor alpha Subunit / Q000235:genetics / Q000378:metabolism*; D008213:Lymphocyte Activation; D009838:Oligodeoxyribonucleotides / Q000494:pharmacology; D061251:Primary Cell Culture; D013388:Succinimides; D050378:T-Lymphocytes, Regulatory / Q000166:cytology* / Q000276:immunology / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000276:immunology / Q000494:pharmacology
chemical_list: C087165:5-(6)-carboxyfluorescein diacetate succinimidyl ester; D018941:Antigens, CD19; D060908:CTLA-4 Antigen; C418974:FOXP3 protein, human; D005452:Fluoresceins; D005456:Fluorescent Dyes; D051858:Forkhead Transcription Factors; D053645:Interleukin-2 Receptor alpha Subunit; D009838:Oligodeoxyribonucleotides; D013388:Succinimides; D016212:Transforming Growth Factor beta; D016753:Interleukin-10