title: Retinoic acid stabilizes antigen-specific regulatory T-cell function in autoimmune hepatitis type 2.
abstract: Imbalance between effector and regulatory T-cells (Treg) underlies the loss of immune-tolerance to self-antigens in autoimmune disease. In autoimmune hepatitis type 2 (AIH-2), effector CD4 T-cell immune responses to cytochrome P450IID6 (CYP2D6) are permitted by numerically and functionally impaired Treg. Restoration of CYP2D6-specific Treg in AIH-2 would enable control over effectors sharing the same antigen specificity, leading to re-establishment of immune-tolerance. We have previously developed a protocol for generating antigen-specific Treg through co-culture with semi-mature dendritic cells presenting CYP2D6 peptides. In this study, we aimed to explore phenotypic and functional features of patient Treg compared to health, to test Treg stability under pro-inflammatory conditions, and to investigate the potential benefit of supplementation with all-trans-retinoic acid (RA) or rapamycin (RP), agents proven to enhance Treg function. We show that antigen-specific Treg from patients have comparable phenotypic and functional features to those from healthy controls, suppressing both proliferation and pro-inflammatory cytokine production by effector cells. Treg exposure to inflammatory challenge results in decreased suppressive function and up-regulation of Th1/Th2/Th17 transcription factors both in health and AIH-2. The increase of Th1 and Th17 transcription factors is limited by addition of RA in controls and Th1 expression is decreased by RP in patients. Importantly, inflammation-induced decrease in Treg function is also abrogated by RA/RP in health and RA in patients. Our data provide important information for the optimization of protocols aiming at generating antigen-specific Treg for treatment of autoimmune disease and for understanding their biology upon pro-inflammatory challenge and RP/RA supplementation.
authors.affiliation: Institute of Liver Studies, King's College London School of Medicine at King's College Hospital, Denmark Hill, London SE5 9RS, UK; Section of Paediatrics, Division of Infectious Diseases, Imperial College London, London, UK.
authors.forename: Beth S
authors.initials: BS
authors.lastname: Holder
authors.affiliation: Institute of Liver Studies, King's College London School of Medicine at King's College Hospital, Denmark Hill, London SE5 9RS, UK.
authors.forename: Charlotte R
authors.initials: CR
authors.lastname: Grant
authors.affiliation: Institute of Liver Studies, King's College London School of Medicine at King's College Hospital, Denmark Hill, London SE5 9RS, UK; Faculdade de Medicina da Universidade do Porto, Porto, Portugal.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Liberal
authors.affiliation: Institute of Liver Studies, King's College London School of Medicine at King's College Hospital, Denmark Hill, London SE5 9RS, UK.
authors.forename: Yun
authors.initials: Y
authors.lastname: Ma
authors.affiliation: Institute of Liver Studies, King's College London School of Medicine at King's College Hospital, Denmark Hill, London SE5 9RS, UK.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Heneghan
authors.affiliation: Institute of Liver Studies, King's College London School of Medicine at King's College Hospital, Denmark Hill, London SE5 9RS, UK; Paediatric Liver, GI & Nutrition Centre, King's College London School of Medicine at King's College Hospital, London, UK.
authors.forename: Giorgina
authors.initials: G
authors.lastname: Mieli-Vergani
authors.affiliation: Institute of Liver Studies, King's College London School of Medicine at King's College Hospital, Denmark Hill, London SE5 9RS, UK.
authors.forename: Diego
authors.initials: D
authors.lastname: Vergani
authors.affiliation: Institute of Liver Studies, King's College London School of Medicine at King's College Hospital, Denmark Hill, London SE5 9RS, UK. Electronic address: maria.longhi@kcl.ac.uk.
authors.forename: Maria Serena
authors.initials: MS
authors.lastname: Longhi
mesh_terms: D000293:Adolescent; D000328:Adult; D000970:Antineoplastic Agents / Q000494:pharmacology*; D002648:Child; D019389:Cytochrome P-450 CYP2D6 / Q000276:immunology; D005260:Female; D019693:Hepatitis, Autoimmune / Q000188:drug therapy / Q000276:immunology / Q000473:pathology; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology; D008297:Male; D020123:Sirolimus / Q000494:pharmacology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology* / Q000473:pathology; D058504:Th17 Cells / Q000276:immunology / Q000473:pathology; D014212:Tretinoin / Q000494:pharmacology*
chemical_list: D000970:Antineoplastic Agents; D007166:Immunosuppressive Agents; D014212:Tretinoin; D019389:Cytochrome P-450 CYP2D6; D020123:Sirolimus
keywords: Autoimmune liver disease; Liver autoantigen; Regulatory T-cell immunotherapy; Stability; Tolerance