Lecture 8 Quiz: T Cell Receptors Flashcards
The following statement correctly describes a common feature of T & B cell development:
a. A single progenitor cell gives rise to lymphocytes of identical specificity.
b. T & B cells undergo stepwise rearrangement of antigen receptor genes.
c. Each lymphocyte can express antigen recognition receptors with multiple specificities.
d. Self-reactive lymphocytes are abundant in the repertoire of mature lymphocytes.
T & B cells undergo stepwise rearrangement of antigen receptor genes. …
A naïve lymphocyte is:
b. A lymphocyte that can become activated once it encounters it specific antigen. a. A mature lymphocyte that is yet to encounter its specific antigen
Developing T cells first express pre T cell receptors: a. At the double positive T cell stage b. After negative selection. c. When they are double negative thymocytes. d. After positive selection.
When they are double negative thymocytes. … A is Incorrect, only alpha:beta T cells become double positive.
Mature alpha:beta T cells:
a. Are exported to the periphery
b. Are double positive for CD4+/CD8+
c. Express CD3 d. Options a & c are correct
a. Are exported to the periphery c. Express CD3 …. B is Incorrect, mature T cells are CD4+ or CD8+ only.
The expression of gamma:delta T cell receptor results in lymphocytes with innate like features, an example of which is that these cells:
a. Recognize unorthodox nucleotides in the context of MHC
b. Do not undergo clonal expansion
c. Have a range of effector functions
d. Have a completely different structure to alpha:beta T cell receptors
Do not undergo clonal expansion … D is Incorrect, both receptors are structurally similar.
Which of the options below does not describe alpha:beta T cell receptor rearrangement:
. TcR rearrangement is RAG-1 & 2 independent.
b. alpha chain rearrangement continues until either a productive rearrangement leads to positive selection or the cell dies.
c. Genes encoding for the beta chain have D, V and J segments.
d. The alpha chain has an increased likelihood of rescue because of multiple successive rearrangement event
TcR rearrangement is RAG-1 & 2 independent. ……
Which of the statements below is incorrect?
a. Activated dendritic cells migrate from tissues to lymphatic vessels in order to reach the lymph nodes.
b. Within lymph nodes T cells inspect antigens presented by dendritic cells.
c. T cells that become activated exit the lymph node to start proliferating in blood.
d. Activated T cells differentiate to become effector cells which can exit the lymph node.
T cells that become activated exit the lymph node to start proliferating in blood.
Which of the statements below is true for costimulatory molecules? a. They mediate the initial interaction between naïve T cells and antigen presenting cells. b. Stimulate the expression of additional co-stimulatory molecules by the antigen presenting cell and induce survival and expansion of the T cell. c. Decrease the production of IL-2 thus promoting T cell expansion and differentiation into effector cells. d. The TcR and costimulatory molecules interact with MHC:peptide complex.
Stimulate the expression of additional co-stimulatory molecules by the antigen presenting cell and induce survival and expansion of the T cell. … Costimulatory molecules stimulate the expression of additional co-stimulatory molecules by the antigen presenting cell and induce survival and expansion of the T cell.
The yellow, red and blue components of the immunological synapse formed between a cytotoxic T cell and its target in the figure below correspond respectively to:
The adhesion zone, signalling and secretory domains. ….. the adhesion zone in yellow corresponds to the outer ring of the immunological synapse, the signalling domain in red lays within this ring, and the secretory domain in blue consists of vesicles within the T cell that transport perforin and granzymes to the immunological synapse to be delivered to the target cell.
QUESTION 10 CD8+ T cell activation requires CD4+ T cell help because:
a. This acts as a mechanism of regulation to prevent uncontrolled cytotoxicity that could negatively impact healthy cells.
b. CD4+ T cells sequester the IL-2 produced by CD8+ T cells as a regulatory mechanism
c. CD4+ T cells reduce the levels of co-stimulatory activity in the antigen presenting cell which avoids excessive activation of the CD8+ T cell.
d. All of the above are correct
This acts as a mechanism of regulation to prevent uncontrolled cytotoxicity that could negatively impact healthy cells.
