Cutting edge: CTLs rapidly capture membrane fragments from target cells in a TCR signaling-dependent manner.
Upon encounter of a CTL with a target cell carrying foreign Ags, the TCR internalizes with its ligand, the peptide-MHC class I complex. However, it is unclear how this can happen mechanistically because MHC molecules are anchored to the target cell's surface via a transmembrane domain. By using antigenic peptides and lipids that were fluorescently labeled, we found that CTLs promptly capture target cell membranes together with the antigenic peptide as well as various other surface proteins. This efficient and specific capture process requires sustained TCR signaling. Our observations indicate that this process allows efficient acquisition of the Ag by CTL, which may in turn regulate lymphocyte activation or elimination.
Institut National de la Santé et de la Recherche Médicale, Unité 395, Centre Hospitalier Universitaire Purpan, BP3028, Toulouse, France. Denis.Hudrisier@purpan.inserm.fr
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D016475:3T3 Cells; D000818:Animals; D017951:Antigen Presentation; D000956:Antigens, Viral; D002462:Cell Membrane / Q000276:immunology / Q000378:metabolism; D003601:Cytotoxicity Tests, Immunologic; D003602:Cytotoxicity, Immunologic; D005434:Flow Cytometry; D016650:Fluorescein-5-isothiocyanate / Q000378:metabolism; D006023:Glycoproteins / Q000276:immunology / Q000378:metabolism; D008217:Lymphocytic choriomeningitis virus / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D010446:Peptide Fragments / Q000276:immunology* / Q000378:metabolism*; D011948:Receptors, Antigen, T-Cell / Q000502:physiology*; D015398:Signal Transduction / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology* / Q000378:metabolism*; D014407:Tumor Cells, Cultured; D014764:Viral Proteins
D000956:Antigens, Viral; D006023:Glycoproteins; D010446:Peptide Fragments; D011948:Receptors, Antigen, T-Cell; D014764:Viral Proteins; C094244:glycoprotein peptide 33-41, Lymphocytic choriomeningitis virus; D016650:Fluorescein-5-isothiocyanate