Keywords:
RECEPTOR
;
CELLS
;
CELL
;
Germany
;
human
;
DISTINCT
;
MOLECULES
;
TIME
;
ACTIVATION
;
COMPLEX
;
MECHANISM
;
DENDRITIC CELLS
;
mechanisms
;
T cell
;
T cells
;
T-CELL
;
T-CELLS
;
SIGNAL
;
MOLECULE
;
cytokines
;
RECOGNITION
;
STIMULATION
;
ACID
;
ACQUISITION
;
EFFICIENT
;
LYMPHOCYTES
;
EXCHANGE
;
NATURAL-KILLER-CELLS
;
ANTIGEN-PRESENTING CELLS
;
CD8(+)
;
specificity
;
LIVE CELLS
;
RECEPTORS
;
CYTOKINE
;
T-CELL-ACTIVATION
;
interaction
;
dendritic cell
;
PHASE
;
EVENTS
;
USA
;
SIGNALS
;
immunology
;
exosomes
;
detachment
;
INTERCELLULAR TRANSFER
;
PEPTIDE-MHC COMPLEXES
Abstract:
Activation of CD4(+) T cells by APCs occurs by multiple Ag recognition events including the exchange of costimulatory signals and cytokines. Additionally, the T cells acquire APC-derived surface molecules. Herein, we describe for the first time the transfer of human and murine T cell surface receptors to APCs after Ag-specific interaction. This transfer occurs in two qualitatively different phases. The first group of molecules (e.g., CD2) derived from the T cell surface was transferred rapidly after 2 h of interaction, was strongly bound on the DC surface (acid wash-resistant), was strictly dependent on dendritic cell-T cell contact, and transferred independently of T cell activation. The second group, including the CD3/TCR complex, CD27, and OX40, was of intracellular origin, transferred later after 10-16 h in a cell-cell contact-independent fashion, was noncovalently bound, and was strictly dependent on Ag-specific T cell activation. Functionally, murine dendritic cells that received TCR molecules from OVA-specific CD4(+) T cells after Ag-specific interaction were less efficient in priming naive CD4(+) T cells of the same specificity without losing their ability for CD8(+) T cell stimulation, indicating that the transferred TCR molecules mask the Ag-bearing MHC II molecules, thereby reducing their accessibility to following Ag-specific CD4(+) T cells. While the first. group of transferred T cell surface molecules might facilitate the detachment of the CD4+ T cell from the dendritic cell during the early scanning phases, the second group could play an important immunomodulatory role in intraclonal competition of T cells for APC access, making the physical presence of CD4(+) T cells unnecessary
Type of Publication:
Journal article published
Deep Link:
http://www.dkfz.de/cgi-bin/sel?http://www.dkfz.de/PublicationManager/Show/ShowJournal.aspx%3fpublishedId=5666
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