Flashcards in The Immunological Synapse Deck (70)
What may control the distribution of membrane receptors?
What is the immunological synapse?
organised structure at the interface between a lymphocyte and an APC or target cell
What is the general function of the immunological synapse?
transger of information
What is the function of the central SMAC?
recognition, co-simtulation and signalling
What is the function of peripheral SMAC//
What does SMAC stand for?
aupra-molecular activation complex
What causes the formation of SMACs on both the T cell and APC?
What organelles play key roles in IS formation?
cytoskeleton and microtubule-organising centre
What are the proposed funhction of the immunological synapse?
signal amplification and integration; co-stimulation; cytotoxicity; directed secretion; protein transfer adn signal termination
What is the function of the adhesion molecules in the SMAC?
affinity for a TCR to its pMHC is low; so need adhesions to form a stable association allowing hte T-cell to inspect the peptides
Which integrins appear important for lymphocyte adhesion?
What enzyme is thought to be invovled in changing the integrin adhesiveness on T cells?
small GTPase Rap1
What tyhpe of signalling is the change in integrin adhesivenesss on T cells known as?
What is the dSMAC?
What interactions take place in the dSMAC?
filamentous actin; CD43/CD45
What initiates the formation of the IS?
TCR engagement; co-stimulation; chemokines
What are the 4 specific stages of IS formation?
initial adhesion; TCR t riggering; organisation; stabilisation
What is the ligand for LFA-1?
What is the ligand for LFA-3?
What is CD43 thought to bind to?
What is the distribution of surface molecules and domains on resting T cells?
What is the function of polairsation in the immunological synapse?
allows the establishment of a sensory contact with APC and early junction formation
What is hte earliest biochemical event in TCR signalling?
tyrosine phophorylation of ITAM sequences
What protein is activatede once Lck mediated phosphorylation of ITAMs has taken place
What proteins are recruited after the activation of ZAP-70?
LAT and SLP-76
What proteins are activated and play a role in cytoskeleton reoganisation?
Vav and WASP
What is the function of cytoskeletal rearragments in the IS?
leads to recruitment of other TCRs and rafts and to synapse organisation
What is the function of stabilisation as the last process of the IS?
allows sustained signallling and optimal activation
What is the difference between the IS in CD4 and CD8 cells?
CD8 cells have an dditional secretory pocket- a mechanism of target killing