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28 Cards in this Set
- Front
- Back
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B cells recognize Ag with cell surface... |
Ig molecules |
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T cells recognize Ag in associations... |
MHC molecules |
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T cells recognize MHC/peptide by... |
TcR (T cell receptors) |
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CD3 is a... |
pan T cell maker |
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Ab-->CD3 can... |
Block T cell recognition |
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3 experimental avenues (1980s) |
1. make Ab to a T cell tumor that did not react with B cells/normal T cells 2. Use of Ab to CD3: found a heteropolymer=CD3 & disulfide linked dimer 3.Subtractive hybridization: used as probes to look for rearrangements in T cells, isolated a B chain |
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TcR Structure (similar to Ab) |
- part of Ig family - both chains exhibit variation in the NH3 terminus but conservation in the COOH terminus -3 CDRs identified in the V region of each TcR chain - Contains a constant region - Connection region: additional cysteines are involved in disulfide linking of 2 chains -Transmembrane region |
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V & J gene segments in... |
a and y-chain families (L chain) |
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V, D, J gene segments in... |
Beta & delta chain families (h chain) |
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Many more ____ gene segments in TcR DNA (only ~~15 in Ab DNA) |
J |
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What are similar to mechanism of B cells? (TcR Gene Organization) |
Rag-1/Rag-2,RSS, Artemis increased TdT |
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Combinatorial events: (Generation of TcR Diversity) |
use of different V-J, V-D-J gene segment combinations |
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Junctional Flexibility: (Generation of TcR Diversity) |
some gene rearrangements are nonproductive |
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Generation of TcR Diversity: |
-N & P region nucleotides addition |
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N region addition in Ig molecules occurs only in... (Generation of TcR Diversity) |
H chain, occurs in all TcR chains |
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No somatic hypermutation in TcR____regions (Generation of TcR Diversity) |
V |
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Add up to a total estimated diversity of... (Generation of TcR Diversity) |
10^11---10^18 |
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TcR selection may be biased towards... |
TcR |
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TcRs with ___________ sequences across unrelated individuals have been described |
identical/near identical |
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The similarity is found in the... |
CDR3 region of the B chain. Usually against viruses |
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Gamma Delta Cells found during... |
fetal development. Production declines after birth & represents only about 0.5% of peripheral T cells in adults |
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may recognize ________ Ags (Gamma Delta Cells) |
unconventional |
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Appear to take up ______ residence in mucosal tissues and skin (Gamma Delta Cells) |
long term |
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What is CD3? |
- involved w. signal transduction after interactions of T cell with Ag - All have "-" charged transmembrane regions that interact with TcR "+" charged transmembrane region - more distant, but related to Ig superfamily
(-)=ALL have (+)=TcR transmembrane region |
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CD3 contains for 4 chains: |
1. Gamma 2. Delta 3. Epsilon 4. Zeta |
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Immune receptor tyrosine-based activation motfit (ITAM) |
All chains shared a common motfit in the cytoplasmic regions |
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CD4 & CD8 proteins are _______&________ |
adhesion molecules & co-signaling coreceptors |
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Accessory Molecules on T cells |
-in general: CD2, LFA-1, CD28, CD45R - bind other surface molecules on APC or target cells - increase strength of adhesion b/w APC or target cells - same on all T cells in all individuals of a species - transduce other signals to the interior of T cells - useful as cell surface markers for our use |
