title: T cells compete by cleaving cell surface CD27 and blocking access to CD70-bearing APCs.
abstract: T cells compete against each other for access to molecules on APCs in addition to peptide/MHC complexes. However, the identity of cell surface molecules that influence T-cell competition, other than peptide/MHC, have yet to be defined. Here, we identify CD70, a TNF ligand expressed on activated APCs, as an important mediator of T-cell competition for APCs. Upon engagement of CD27 by CD70, CD27 is proteolytically cleaved from the surface of the interacting CD8(+) T cell and captured by CD70 expressing dendritic cells. The capture of CD27 effectively masks CD70 on APCs, disallowing the interaction with CD27 on other competing T cells. Collectively, our data indicate that T cells compete against each other for access to the TNF-ligand CD70, an interaction that affects the duration and potency of T cell/DC interactions, thus influencing the repertoire of responding CD8(+) T cells to self or foreign antigens.
authors.affiliation: School of Medicine, Department of Immunology and Microbiology, University of Colorado Denver, Aurora, CO, USA.
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Burchill
authors.affiliation: School of Medicine, Department of Immunology and Microbiology, University of Colorado Denver, Aurora, CO, USA.
authors.forename: Beth A
authors.initials: BA
authors.lastname: Tamburini
authors.affiliation: School of Medicine, Department of Immunology and Microbiology, University of Colorado Denver, Aurora, CO, USA.
authors.forename: Ross M
authors.initials: RM
authors.lastname: Kedl
mesh_terms: D000818:Animals; D053282:CD27 Ligand / Q000276:immunology* / Q000378:metabolism; D018920:Coculture Techniques; D003713:Dendritic Cells / Q000276:immunology*; D008213:Lymphocyte Activation / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D013601:T-Lymphocytes / Q000276:immunology*; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7 / Q000276:immunology* / Q000378:metabolism
chemical_list: D053282:CD27 Ligand; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7
keywords: CD27; CD70; CD8 T cell; Competition; Dendritic cell