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Which of the following statement(s) is/are CORRECT for antigen activated effector T cells?
P. CD4+ cells make contact with macrophages and stimulate their microbicidal activity
Q. CD4+ cells make contact with B cells and stimulate them to differentiate into plasma cells
R. CD8+ cells make contact with B cells and stimulate them to differentiate into plasma cells
S. CD8+ cells make contact with virus infected cells and kill them
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- Q only
- Q and S only
- P, Q and S only
- P, Q, R and S
Correct Option: C
Activated effector T cells or CD4+ cells initially contact with the macrophages which possess its receptor and stimulate microbial activity. It also make contact with B cells and stimulate differentiation into plasma cells. On contrary CD8+ cells make contact with B cells and stimulate differentiation into plasma cells. CD4 is a co-receptor that assists the T cell receptor (TCR) in communicating with an antigen-presenting cell. Using its intracellular domain, CD4 amplifies the signal generated by the TCR by recruiting an enzyme, the tyrosine kinase Lck, which is essential for activating many molecular components of the signaling cascade of an activated T cell.
