The schematic drawing below summarizes the differentiation of naïve helper T cells (TH cells) into various effector T cells, which occurs in a peripheral lymphoid organ. Indicate which effector cell (A to E) in the drawing is better described by each of the following descriptions. Your answer would be a four-letter string composed of letters A to E only, e.g. DEAE.

( ) It can also develop from thymocytes in the thymus, as well as from naïve TH cells.
( ) It suppresses the development, activation, or function of most other immune cells.
( ) It produces IFN? and activates macrophages.
( ) They reside in lymphoid follicles close to developing B cells.

Question

The schematic drawing below summarizes the differentiation of naïve helper T cells (TH cells) into various effector T cells, which occurs in a peripheral lymphoid organ. Indicate which effector cell (A to E) in the drawing is better described by each of the following descriptions. Your answer would be a four-letter string composed of letters A to E only, e.g. DEAE.
  
( )	It can also develop from thymocytes in the thymus, as well as from naïve TH cells.
( )	It suppresses the development, activation, or function of most other immune cells.
( )	It produces IFN? and activates macrophages.
( )	They reside in lymphoid follicles close to developing B cells.

Quizplus · Accepted Answer

Regulatory (suppressor) T cells can develop from thymocytes in the thymus as well as from naïve TH cells in peripheral tissues. TH1 cells secrete interferon-? (IFN?) which activates macrophages and induces B cells to switch the class of Ig they make. TFH cells reside in lymphoid follicles and secrete a variety of cytokines; they are especially important for the stimulation of Ig class switching and somatic hypermutation in B cells.

The Schematic Drawing Below Summarizes the Differentiation of Naïve Helper