Which of the tracing is NOT the role of T-cell receptor complex?
A.
α and β chain
B.
CD3
C.
CD19
D.
CD40L
Answer: Option C
Explanation:
CD19 is a co-receptor of B-cell receptor complex while T-cell receptor complex consists of antigen recognizing α and β chains, expressed on the surface of T-cell in noncovalent association with CD3 molecule. CD40L and CD28 are co-stimulatory molecules.
Name the syndrome occurs in children due to deficiency of the thymus.
A.
Acromegaly
B.
Gigantism
C.
Cushing syndrome
D.
DiGeorge syndrome
Answer: Option D
Explanation:
Thymus is required for the development of T-cells. Children which are born without thymus undergo adverse effects of not having matured T-cells; this syndrome is known as DiGeorge syndrome.
Which of the following steps is NOT involved in the activation of T-cell?
A.
Double positive cell converts to single positive T-cell
B.
Foreign peptide bound to MHC provide signals
C.
CD28 of TCR interacts with B7 of APC
D.
CD23 has ITAM, which transducer signals
Answer: Option A
Explanation:
The conversion of double positive cells to a single positive cell is thymic selection process in which T-cell mature with the interaction of MHC and develops the tolerance to self-antigen.
Name the cytokines which act as a T-cell growth factor?
A.
IL-3
B.
IL-2
C.
IL-4
D.
IL-5
Answer: Option B
Explanation:
Cytokines released by T-helper cells and have several functions like IL-2 act as T-cell growth factor while IL-4 and IL-5 help in B-cell activation, IL-3 involved in hematopoiesis and secreted by both TH1 and TH2 subset of T-helper cell.
Cytokinin which acts as a growth factor of B-cell is________
A.
IFNγ
B.
IL-10
C.
IL-13
D.
TNFβ
Answer: Option C
Explanation:
IL-13 is secreted by TH2 and act as B-cell growth factor while IL-10 inhibits macrophages, while IFNγ and TNFβ secreted by TH1 and used to activate macrophages and inflammatory responses.
