title: Differential Effects of Calcineurin and Mammalian Target of Rapamycin Inhibitors on Alloreactive Th1, Th17, and Regulatory T Cells.
abstract: BACKGROUND
  Previously, we had reported the role of tacrolimus (TAC) versus sirolimus (SRL) on the generation of regulatory T cells (Tregs) in primary MLR assays with SRL, demonstrating a uniquely supportive effect. However, the mechanisms associated with their actions on alloreactive human T cells are not fully understood. Therefore, we tested whether TAC and SRL differentially affect already alloactivated human CD4 T-cell subsets.
  
  
  METHODS
  Alloreactive CD4CD45RA/CD45RO T cells generated in 9-day MLR were cocultured with anti-CD3 and autologous antigen presenting cells plus interleukin (IL)-2 in presence of TAC, SRL, or both, and the Tregs generated after another 5 to 6 days were phenotypically, molecularly, and functionally characterized.
  
  
  RESULTS
  Tacrolimus significantly and SRL modestly inhibited interferon (IFN)-γ (Th1) and IL-17 (Th17)-producing cells. At clinical therapeutic concentrations, SRL, however, significantly increased forkhead/winged helix transcription factor P3 (FOXP3) Tregs, whereas TAC inhibited this T-cell population dose dependently and significantly. When used in combination, TAC and SRL had additive effects on inhibition of IFN-γ- and IL-17-producing cells. This was in contrast to the ability of SRL to reverse TAC-mediated inhibition of FOXP3-expressing cells. Proinflammatory cytokines (IL-1β, IL-6, and tumor necrosis factor-α) added to cultures caused significant decrease in FOXP3 Tregs that was again reversed by SRL. Sirolimus-derived Tregs were phenotypically normal, anergic to allostimulation, and suppressed proliferation of allogeneic effector T-cells.
  
  
  CONCLUSIONS
  Thus, although TAC inhibits all alloreactive T cells, SRL promotes the differentiation and expansion of donor-specific Tregs without secondary reprogramming to IFN-γFOXP3 and IL-17FOXP3 Treg subsets. These results, although performed in an artificial in vitro model, add clinically applicable information on how these agents affect T-cell subpopulations.
authors.affiliation: 1 Department of Medicine-Nephrology, Northwestern University Feinberg School of Medicine, Chicago, IL. 2 Comprehensive Transplant Center, Northwestern University Feinberg School of Medicine, Chicago, IL. 3 Department of Surgery, Northwestern University Feinberg School of Medicine, Chicago, IL. 4 Department of Medicine and Rheumatology Division, Northwestern University Feinberg School of Medicine, Chicago, IL. 5 Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL. 6 Department of Surgery, University of Virginia, Charlottesville, VA.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Gallon
authors.forename: Opas
authors.initials: O
authors.lastname: Traitanon
authors.forename: Yuming
authors.initials: Y
authors.lastname: Yu
authors.forename: Bo
authors.initials: B
authors.lastname: Shi
authors.forename: Joseph R
authors.initials: JR
authors.lastname: Leventhal
authors.forename: Joshua
authors.initials: J
authors.lastname: Miller
authors.forename: Valeria
authors.initials: V
authors.lastname: Mas
authors.forename: Xu
authors.initials: X
authors.lastname: L
authors.forename: James M
authors.initials: JM
authors.lastname: Mathew
mesh_terms: D015415:Biomarkers / Q000378:metabolism; D065095:Calcineurin Inhibitors / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D018920:Coculture Techniques; D016207:Cytokines / Q000378:metabolism; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D018836:Inflammation Mediators / Q000378:metabolism; D008213:Lymphocyte Activation / Q000187:drug effects; D010641:Phenotype; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects; D020123:Sirolimus / Q000494:pharmacology*; D050378:T-Lymphocytes, Regulatory / Q000187:drug effects* / Q000201:enzymology / Q000276:immunology; D058570:TOR Serine-Threonine Kinases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D016559:Tacrolimus / Q000494:pharmacology*; D018417:Th1 Cells / Q000187:drug effects* / Q000201:enzymology / Q000276:immunology; D058504:Th17 Cells / Q000187:drug effects* / Q000201:enzymology / Q000276:immunology; D013997:Time Factors
chemical_list: D015415:Biomarkers; D065095:Calcineurin Inhibitors; D016207:Cytokines; D007166:Immunosuppressive Agents; D018836:Inflammation Mediators; D047428:Protein Kinase Inhibitors; C546842:MTOR protein, human; D058570:TOR Serine-Threonine Kinases; D020123:Sirolimus; D016559:Tacrolimus