34 Questions
What is the function of the T cell receptor (TCR)?
To signal T cells for activation
Where do T cells develop from precursor cells?
Thymus
What determines the antigen specificity of a lymphocyte?
DNA sequences encoding the variable regions of the TCR
What is the distinctive feature of T cells in terms of antigen recognition?
Recognizing short peptide fragments of pathogen’s protein antigens bound to MHC molecules
What is the structure of the T cell receptor (TCR)?
Consists of α and β polypeptide chains linked by a disulphide bond
How many identical antigen receptor molecules does each T cell bear on its surface?
Approximately 30,000
What is the similarity in structure between the α:β heterodimer of TCR and antibodies?
Similar in structure to Fab fragment of Ab
How many binding sites does the T cell receptor (TCR) have?
One
What is the primary location for T cell receptor (TCR) testing for antigen-recognition properties?
Immediate environment
What is the main function of the T cell receptor (TCR) in recognizing antigen?
Recognizes short peptide fragments of pathogen’s protein antigens
What is the relationship between T cell receptor (TCR) and antibody molecules?
Closely related
What is the only function of the T cell receptor (TCR)?
To signal T cells for activation
What is the role of the short hinge region in the T cell receptor (TCR) structure?
It contains a cysteine residue that forms the disulphide link between the 2 chains
What distinguishes CD4 helper T cells from CD8 cytotoxic T cells?
Expression of cell surface proteins CD4, CD8
What is the consequence of CD4/8 binding alone to MHC?
No signal
Which cells express little or no MHC1?
Non-nucleated cells
What is the primary function of CD8 cytotoxic T cells?
Specialized to kill any cell they recognize
Where are MHC2 molecules found?
Dendritic cells, B cells, and macrophages
What is the consequence of T cells being alerted to all possible infections?
MHC molecules must be capable of binding stably to many different peptides
What is the primary role of CD4 helper T cells in the immune response?
Stimulate antibody production
What is the consequence of stable binding of peptides to MHC molecules?
Stability of bound peptides is very important
What is the ligand recognized by the TCR?
Complex of peptide and MHC molecule
What is the function of the hydrophobic transmembrane domain in the TCR structure?
Anchors the TCR in the cell membrane
What is the role of CD4/8 in enhancing the sensitivity of the cell to antigen presented by MHC?
Deliver a kinase close to the signaling components of the TCR complex
What is the function of the short hinge region in the T cell receptor (TCR) structure?
It contains a cysteine residue that forms the disulphide link between the 2 chains
Where are MHC2 molecules found?
Dendritic cells, B cells, and macrophages
What is the consequence of CD4/8 binding alone to MHC?
No signal is generated
What is the distinctive feature of T cells in terms of antigen recognition?
They recognize short amino acid sequences of proteins
What is the consequence of stable binding of peptides to MHC molecules?
No signal is generated
What is the role of CD4/8 in enhancing the sensitivity of the cell to antigen presented by MHC?
They interact with an thyrosine kinase in the cytoplasm and can deliver this kinase close to the signaling components of the TCR complex
What is the consequence for plasmodium species due to non-nucleated cells expressing little or no MHC1?
They live undetected in red blood cells
What is the primary location for T cell receptor (TCR) testing for antigen-recognition properties?
Amino terminal variable (V) region
What is the consequence of T cells being alerted to all possible infections?
They must be capable of binding stably to many different peptides
What is the role of the hydrophobic transmembrane domain in the TCR structure?
It anchors the TCR in the cell membrane
Test your knowledge of T cell development, antigen recognition, and antigen presentation in immunology with this quiz. Challenge yourself with questions about the origin of lymphocytes, T cell maturation in the thymus, and the determination of antigen specificity.
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