title: SAHA, an HDAC inhibitor, synergizes with tacrolimus to prevent murine cardiac allograft rejection.
abstract: Suberoylanilide hydroxamic acid (SAHA), as a histone deacetylase (HDAC) inhibitor (HDACi), was recently found to exhibit an immunosuppressive effect. However, whether SAHA can synergize with calcineurin inhibitors (CNIs) to inhibit allograft rejection and its underlying mechanism remain elusive. In this study, we demonstrated the synergistic effects of SAHA and non-therapeutic dose of tacrolimus (FK506) in prolonging the allograft survival in a murine cardiac transplant model. Concomitant intragraft examination revealed that allografts from SAHA-treated recipients showed significantly lower levels of IL-17 expression, and no discernable difference for IL-17 expressions was detected between SAHA- and SAHA/FK506-treated allograft as compared with allografts from FK506-treated animals. In contrast, administration of FK506 significantly suppressed interferon (IFN)-γ but increased IL-10 expression as compared with that of SAHA-treated animals, and this effect was independent of SAHA. Interestingly, SAHA synergizes with FK506 to promote Foxp3 and CTLA4 expression. In vitro, SAHA reduced the proportion of Th17 cells in isolated CD4⁺ T-cell population and decreased expressions of IL-17A, IL-17F, STAT3 and RORγt in these cells. Moreover, SAHA enhances suppressive function of regulatory T (Treg) cells by upregulating the expression of CTLA-4 without affecting T effector cell proliferation, and increased the proportion of Treg by selectively promoting apoptosis of T effector cells. Therefore, SAHA, a HDACi, may be a promising immunosuppressive agent with potential benefit in conjunction with CNI drugs.
authors.affiliation: Institute of Organ Transplantation, Changzheng Hospital, Shanghai, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhang
authors.forename: Shu
authors.initials: S
authors.lastname: Han
authors.forename: Yindong
authors.initials: Y
authors.lastname: Kang
authors.forename: Meng
authors.initials: M
authors.lastname: Guo
authors.forename: Shanjuan
authors.initials: S
authors.lastname: Hong
authors.forename: Fang
authors.initials: F
authors.lastname: Liu
authors.forename: Shangxi
authors.initials: S
authors.lastname: Fu
authors.forename: Liming
authors.initials: L
authors.lastname: Wang
authors.forename: Quan-Xing
authors.initials: QX
authors.lastname: Wang
mesh_terms: D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism; D060908:CTLA-4 Antigen / Q000378:metabolism; D049109:Cell Proliferation; D004357:Drug Synergism; D051858:Forkhead Transcription Factors / Q000378:metabolism; D016027:Heart Transplantation; D056572:Histone Deacetylase Inhibitors / Q000494:pharmacology*; D006877:Hydroxamic Acids / Q000494:pharmacology*; D007166:Immunosuppressive Agents / Q000494:pharmacology* / Q000627:therapeutic use; D020381:Interleukin-17 / Q000276:immunology / Q000378:metabolism; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D016559:Tacrolimus / Q000494:pharmacology* / Q000627:therapeutic use; D014184:Transplantation, Homologous / Q000276:immunology; D000077337:Vorinostat
chemical_list: D060908:CTLA-4 Antigen; C556707:Ctla4 protein, mouse; D051858:Forkhead Transcription Factors; C498833:Foxp3 protein, mouse; D056572:Histone Deacetylase Inhibitors; D006877:Hydroxamic Acids; D007166:Immunosuppressive Agents; D020381:Interleukin-17; D000077337:Vorinostat; D016559:Tacrolimus