title: Real-time immune cell interactions in target tissue during autoimmune-induced damage and graft tolerance.
abstract: Real-time imaging studies are reshaping immunological paradigms, but a visual framework is lacking for self-antigen-specific T cells at the effector phase in target tissues. To address this issue, we conducted intravital, longitudinal imaging analyses of cellular behavior in nonlymphoid target tissues to illustrate some key aspects of T cell biology. We used mouse models of T cell-mediated damage and protection of pancreatic islet grafts. Both CD4(+) and CD8(+) effector T (Teff) lymphocytes directly engaged target cells. Strikingly, juxtaposed β cells lacking specific antigens were not subject to bystander destruction but grew substantially in days, likely by replication. In target tissue, Foxp3(+) regulatory T (Treg) cells persistently contacted Teff cells with or without involvement of CD11c(+) dendritic cells, an observation conciliating with the in vitro "trademark" of Treg function, contact-dependent suppression. This study illustrates tolerance induction by contact-based immune cell interaction in target tissues and highlights potentials of tissue regeneration under antigenic incognito in inflammatory settings.
authors.affiliation: Department of Microbiology and Immunology and 2 Department of Surgery, 3 Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, FL 33136 4 Department of Biomedical Engineering, University of Miami, Coral Gables, FL 33124.
authors.forename: Jason
authors.initials: J
authors.lastname: Miska
authors.forename: Midhat H
authors.initials: MH
authors.lastname: Abdulreda
authors.forename: Priyadharshini
authors.initials: P
authors.lastname: Devarajan
authors.forename: Jen Bon
authors.initials: JB
authors.lastname: Lui
authors.forename: Jun
authors.initials: J
authors.lastname: Suzuki
authors.forename: Antonello
authors.initials: A
authors.lastname: Pileggi
authors.forename: Per-Olof
authors.initials: PO
authors.lastname: Berggren
authors.forename: Zhibin
authors.initials: Z
authors.lastname: Chen
mesh_terms: D019264:Adoptive Transfer; D000704:Analysis of Variance; D000818:Animals; D001324:Autoantigens / Q000276:immunology; D015551:Autoimmunity / Q000276:immunology*; D001973:Bromodeoxyuridine; D002450:Cell Communication / Q000276:immunology*; D003433:Crosses, Genetic; D005453:Fluorescence; D007091:Image Processing, Computer-Assisted / Q000379:methods; D016381:Islets of Langerhans Transplantation / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D034622:RNA Interference; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*; D023001:Transplantation Tolerance / Q000276:immunology*
chemical_list: D001324:Autoantigens; D001973:Bromodeoxyuridine