IL2 production

IL-2 is produced by CD4 T lymphocytes. During the immune response CD4 lymphocytes differentiate into Th1 and TH2 functional subsets. This pattern of differentiation is very clear in the mouse, where T,, I lymphocytes produce IL-2 and interferon 7, and T, ,2 lymphocytes produce IL-4, IL-5 and IL-6. In humans, however, this functional dichotomy of CD4 lymphocytes is less distinct.

Resting CD4 lymphocytes do not produce IL-2. Two types of signals (signal l and signal 2) induce the production of IL-2. Signal l is dependent on the binding of the T cell receptor (TCR) to the antigen/MHC (major histocompatibility complex) complex. It can be mimicked by antibody against the TCR or by some lectins. Signal 2 follows the binding of T cell surface molecules such as CD28 or CTLA-4 to B7-2 and B7-1 present on the surface of the antigen-presenting cells. Maximum production of IL-2 occurs when both signals are present. Other costimu-lating molecules (cell surface antigens, cytokines) are also involved in the optimal production of IL-2. Alone, signal 1 induces an anergy of the TH lymphocytes. This anergic state is characterized by the inability to react to a second antigenic signal. IL-2 can replace signal 2 and prevent the induction of an anergic state.

Some CD8 clones can produce small amounts of IL-2. Under certain conditions B lymphocytes are also able to produce IL-2: Fpstein-Barr virus (EBV)-infected lines produce IL-2 as well as normal B lymphocytes cultured in the presence of anti-CD40 monoclonal antibodies (mAb) and IL-4 and subsequently stimulated by phorbol esters and calcium ionophore.

The transcription of the IL-2 gene is highly regulated by a 300 bp promoter. This promoter region can bind many transcription factors. Among them two NFAT factors (p and c) and AP-1 (heterodimer of fos and jun) are essential.

How To Bolster Your Immune System

How To Bolster Your Immune System

All Natural Immune Boosters Proven To Fight Infection, Disease And More. Discover A Natural, Safe Effective Way To Boost Your Immune System Using Ingredients From Your Kitchen Cupboard. The only common sense, no holds barred guide to hit the market today no gimmicks, no pills, just old fashioned common sense remedies to cure colds, influenza, viral infections and more.

Get My Free Audio Book


Post a comment