Which one of the following descriptions of cytokine interleukin-2 is NOT true?
A)Expression of its gene requires multiple transcription factors,such as Fos,Jun,and NFAT.
B)It acts as an autocrine growth factor for T cells.
C)It binds to CD25 on the cell membrane of T cells.
D)It is only involved in the proliferation of helper T cells and not CTLs.
E)It promotes susceptibility of T cells to apoptosis.

Question

Quizplus · Accepted Answer

IL-2 is involved in the proliferation of both CD4⁺ and CD8⁺ T cells.Activation of the naive T cell results in signals transduced via the TCR (signal 1)and CD28 (signal 2).This signaling results in the activation of transcription factors,such as Fos,Jun,and NFAT,which increase transcription of the IL-2 gene.IL-2 is then secreted and acts as both a paracrine and autocrine growth factor for T cells by binding to the IL-2 receptor (one component of which is CD25).In addition to its growth factor activity,IL-2 also "primes" T cells for apoptotic death,and this role for IL-2 is important in homeostasis of the immune system.

Which One of the Following Descriptions of Cytokine Interleukin-2 Is