MCQ – 25195

All of the following are functions of CD 4 helper cells, except –

A.	Immunogenic memory
B.	Produce immnoglobulins
C.	Activate macrophages
D.	Activate cytotoxic cells

Show Answer

Correct Answer � B Explanation

Ans. is. ‘b’ i.e., Produce immunoglobulins

.  Based on secretion of different cytokines CD4 Helper T cells are divided into THI and TI-U (see previous explanation).

.  Based on function CD4 helper T cells are divided into‑

1) Effector CD4 helper Tcells

–  These cells secrete cytokines and other products that perform all major functions.

–  These include TH 1 and TH2 helper cells (see previous explanation).

–   Functions are‑

A) By THI cells

i)         Activate macrophages

ii)       Delayed hypersensitivity

iii)      Cell mediated immunity

iv)      Killing of intracellular microbes.e.g. tuberculosis and leprosy

v)       Destruction of target cells by‑

a)       Activate CD8 T cells to become cytotoxic cells.

b)       Activate NK cells

B)       By TH2 cells

i) Activate B cells to develop into antibody producing plasma cells —> facilitate synthesis of antibodies.

2) Memory CD4 helper T cells

–  Retain the antigenic affinity of the originally activated T cells and are used to act as later effector cells during a second immune response.