title: Contrasting impacts of immunosuppressive agents (rapamycin, FK506, cyclosporin A, and dexamethasone) on bidirectional dendritic cell-T cell interaction during antigen presentation.
abstract: Rapamycin (RAP), tacrolimus (FK506), cyclosporin A, and glucocorticoids represent modern and classic immunosuppressive agents being used clinically. Although these agents have distinct molecular mechanisms of action and exhibit different immunoregulatory profiles, their direct influences on Ag presentation processes remain relatively unknown. Here we report quantitative and qualitative differences among the above four immunosuppressants in their impact on Ag-specific, bidirectional interaction between dendritic cells (DC) and CD4(+) T cells. In the presence of relevant Ag, bone marrow-derived DC delivered activation signals to CD4(+) T cells isolated from the DO11.10 TCR transgenic mice, leading to clonal expansion; secretion of IFN-gamma, IL-2, and IL-4; and surface expression of CD69. Conversely, DO11.10 T cells delivered maturation signals to DC, leading to IL-6 and IL-12 production and CD40 up-regulation. FK506 (10(-10)-10(-8) M) and cyclosporin A (10(-9)-10(-7) M) each blocked efficiently and uniformly all the changes resulting from intercellular signaling in both DC-->T cell and T cell-->DC directions. Dexamethasone (10(-9)-10(-6) M) suppressed all changes, except for CD69 up-regulation, rather incompletely. Remarkably, RAP (10(-10)-10(-8) M) efficiently inhibited DC-induced T cell proliferation and T cell-mediated CD40 up-regulation by DC without abrogating other changes. Interestingly, T cell-independent DC maturation triggered by LPS stimulation was inhibited by dexamethasone, but not by other agents. Our results demonstrate contrasting pharmacological effects of RAP vs calcineurin inhibitors on Ag presentation, thus forming a conceptual framework for rationale-based selection (and combination) of immunosuppressive agents for clinical application.
authors.affiliation: Department of Dermatology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA. hiroyuki.matsue@utsouthwestern.edu
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Matsue
authors.forename: Chendong
authors.initials: C
authors.lastname: Yang
authors.forename: Keiko
authors.initials: K
authors.lastname: Matsue
authors.forename: Dale
authors.initials: D
authors.lastname: Edelbaum
authors.forename: Mark
authors.initials: M
authors.lastname: Mummert
authors.forename: Akira
authors.initials: A
authors.lastname: Takashima
mesh_terms: D000818:Animals; D017951:Antigen Presentation / Q000187:drug effects*; D002450:Cell Communication / Q000187:drug effects / Q000276:immunology*; D002478:Cells, Cultured; D018920:Coculture Techniques; D016572:Cyclosporine / Q000494:pharmacology; D003713:Dendritic Cells / Q000166:cytology / Q000187:drug effects* / Q000276:immunology* / Q000378:metabolism; D003907:Dexamethasone / Q000494:pharmacology; D005260:Female; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D008070:Lipopolysaccharides / Q000494:pharmacology; D051379:Mice; D008807:Mice, Inbred BALB C; D008822:Mice, Transgenic; D020123:Sirolimus / Q000494:pharmacology; D013601:T-Lymphocytes / Q000187:drug effects* / Q000276:immunology* / Q000378:metabolism; D016559:Tacrolimus / Q000494:pharmacology
chemical_list: D007166:Immunosuppressive Agents; D008070:Lipopolysaccharides; D003907:Dexamethasone; D016572:Cyclosporine; D020123:Sirolimus; D016559:Tacrolimus