Immunological synapses are versatile structures enabling selective T cell polarization.
Helper T cells discriminate among different antigen-presenting cells to provide their help in a selective fashion. The molecular mechanisms leading to this exquisite selectivity are still elusive. Here, we demonstrate that immunological synapses are dynamic and adaptable structures allowing T cells to communicate with multiple cells. We show that T cells can form simultaneous immunological synapses with cells presenting different levels of antigenic ligands but eventually polarize toward the strongest stimulus. Remarkably, living T cells form discrete foci of signal transduction of different intensities during the interaction with different antigen-presenting cells and rapidly relocate TCR and Golgi apparatus toward the cell providing the strongest stimulus. Our results illustrate that, although T cell activation requires sustained signaling, T cells are capable of rapid synapse remodeling and swift polarization responses. The combination of sustained signaling with preferential and rapid polarization provides a mechanism for the high sensitivity and selectivity of T cell responses.
Depoil
David
D
INSERM U563, Lymphocyte Interaction Group, Institut Claude de Préval, 31059 Toulouse.
Zaru
Rossana
R
Guiraud
Martine
M
Chauveau
Anne
A
Harriague
Julie
J
Bismuth
Georges
G
Utzny
Clemens
C
Müller
Sabina
S
Valitutti
Salvatore
S
D000818:Animals; D000938:Antigen-Presenting Cells / Q000166:cytology / Q000276:immunology; D018801:CD2 Antigens / Q000276:immunology / Q000378:metabolism; D018968:CD58 Antigens / Q000276:immunology / Q000378:metabolism; D002460:Cell Line; D016764:Cell Polarity; D006801:Humans; D007365:Intercellular Junctions / Q000378:metabolism*; D051379:Mice; D011948:Receptors, Antigen, T-Cell / Q000276:immunology / Q000378:metabolism; D013379:Substrate Specificity; D013601:T-Lymphocytes / Q000166:cytology* / Q000276:immunology* / Q000378:metabolism
D018801:CD2 Antigens; D018968:CD58 Antigens; D011948:Receptors, Antigen, T-Cell