Question

15. What is a major difference between Th and Tc cells? A. Tc can bind to almost any infected cell; Th only bind infected antigen presenting cells B. Tc mostly secrete cytokines; Th secrete histamine C. Effector Ty cells induce apoptosis; effector Tc cells induce humoral immunity D. TH cells produce B7, but Tc cells produce interleukin-2 E. T cells undergo clonal deletion; Tc undergo clonal expansion

Answer 1

Q15. Answer

A. Tc binds to almost any infected cell but Th binds only to APCs.

Explanation- Th binds to CD40 on APCs, which leads to many effects depending on the target cell type.

Tc cells bind to cells with a MHC1 presenting the specific antigen.

Tc cells secrete immunoglobulins and Th cells secrete cytokines. Tc cells induce apoptosis and Th cells induce humoral immunity. Interleukins are released by Th cells as co-stimulatory signals to complete B cell activation
They also stimulate B cells to divide more rapidly and begin clonal expansion.

Q19. Answer

D

E.Th cells could never mature and Differentiate to Tc cells.

Explanation- IL-4,5,6 are required for B cell activation.