title: Soluble peptide-MHC monomers cause activation of CD8+ T cells through transfer of the peptide to T cell MHC molecules.
abstract: T cell receptor (TCR)-mediated activation of CD4(+) T cells is known to require multivalent engagement of the TCR by, for example, oligomeric peptide-MHC complexes. In contrast, for CD8(+) T cells, there is evidence for TCR-mediated activation by univalent engagement of the TCR. We have here compared oligomeric and monomeric L(d) and K(b) peptide-MHC complexes and free peptide as stimulators of CD8(+) T cells expressing the 2C TCR. We found that the monomers are indeed effective in activating naive and effector CD8(+) T cells, but through an unexpected mechanism that involves transfer of peptide from soluble monomers to T cell endogenous MHC (K(b)) molecules. The result is that T cells, acting as antigen-presenting cells, are able to activate other naive T cells.
authors.affiliation: Department of Biology, Center for Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: Qing
authors.initials: Q
authors.lastname: Ge
authors.forename: Jennifer D
authors.initials: JD
authors.lastname: Stone
authors.forename: M Todd
authors.initials: MT
authors.lastname: Thompson
authors.forename: Jennifer R
authors.initials: JR
authors.lastname: Cochran
authors.forename: Mia
authors.initials: M
authors.lastname: Rushe
authors.forename: Herman N
authors.initials: HN
authors.lastname: Eisen
authors.forename: Jianzhu
authors.initials: J
authors.lastname: Chen
authors.forename: Lawrence J
authors.initials: LJ
authors.lastname: Stern
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017951:Antigen Presentation; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D002999:Clone Cells; D015395:Histocompatibility Antigens Class I / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D066298:In Vitro Techniques; D008213:Lymphocyte Activation; D051379:Mice; D018345:Mice, Knockout; D008822:Mice, Transgenic; D018448:Models, Immunological; D010455:Peptides / Q000737:chemistry* / Q000276:immunology*; D011948:Receptors, Antigen, T-Cell / Q000235:genetics / Q000378:metabolism
chemical_list: D015395:Histocompatibility Antigens Class I; D010455:Peptides; D011948:Receptors, Antigen, T-Cell