Cytokines and their receptors

What is a cytokines?

Proteins secreted by cells of the immune system (cell communication)

What do cytokines receptors do?

Bind and cause genes to be activated to communicate between cells

Can inhibit or activate gene expression in nucleus

Cytokines differ from hormones?

PLEIOTROPY: act on many different CELL TYPES and produce different responses

REDUNDANCY: MANY act on one cell type to induce one type of response

Influence production of other cytokines

Hormones are specific cell w/ specific cell target for homeostasis

How are cytokines named?

Based on function:

Interleukins: lymphocytes/leukocytes interactions

Interferons: Anti-viral function

Tumor necrosis factor (TNF): immune function and anti-tumor

Growth factors: Regulate stem cell growth

Chemokines: Chemotaxis of immune cells - BASED ON STRUCTURE

How do cytokines exert their effects?

Autocrine: to self-cell

Paracrine: to nearby cells

Endocrine: passes through blood stream to reach destination cell

What are the general functions of cytokines?

Self-limited with brief secretion

Regulate their receptor expression alteration, binding proteins to bring cytokines, or other cytokines exerting

What are specific functions of some of the common cytokines?

Cytokines act as growth factors: EPO, GCSF, IL-7, GMCSF, 1L-14 (4s)

Examples of cytokines pleiotropy: IL-2 (inflammatory, anti-inflammatory, growth factor functions)

Why IL-6 is more dangerous:soluble receptor used instead of membrane-bound receptor, signals for all cells regardless of other receptors bound (anti-inflammatory/inflammatory)