Cytokine in health and Disease

Question 1

what are the general cahrcteristics of cytokines?

Answer 1

Non-antigen specific proteins, synthesized and rapidly secreted. Not usually stored within a cell and have short half-lives.

They act locally or systemically.

Bind to specific receptors on the target cell.

Amplify immune response.

Question 2

What are the properties of cytokines? (there are four properties)

Answer 2

PLEITROPIC PROPERTIES: meaning that one cytokine can affect
the activity of many different target cell types.

FUNCTIONAL REDUNDANCY: meaning that more than one cytokine can act on a single cellular target.

SYNERGY EFFECT: the combined effect of 2 cytokines is greater than the sum of their individual effects.

ANTAGONISTIC EFFECTS:one cytokine can inhibit the biological activity
of another cytokine.

Question 3

In what ways, can a cytokine affect other cells? (Autocrine, paracrine, endocrine)

Answer 3

Autocrine: act locally on the same cell that secreted it.

Paracrine: act on other NEARBY cells.

Endocrine: act systemically . (DISTANT cells)

Question 4

What groups are present within cytokines?

Answer 4

A) INTERLEUKINS (ILs) regulate the interactions between leukocytes. ( can act on cell types other than leukocytes)(e.g. IL-2, IL-3, IL-4 etc).

B) INTERFERONS(IFNs): interfere viral
replication within host cells. They also have other functions.
a)Type I (IFN-alpha and IFN-beta)-synthesized in response to viruses by virus infected cells
b) Type II (IFN-y)-produced by activated T cells and NK cells.

C) TUMOR NECROSIS FACTORS (TNFs) cause NECROSIS of tumors by inducing local INFLAMMATION AND THROMBOSIS of tumor blood vessels.
derived from MACROPHAGES (TNF-alpha) and T cells (TNF-alpha and TNF-beta/lymphotoxin alpha)

d) COLONY STIMULATING FACTORS (CSF) promote the expansion and differentiation of bone-marrow progenitor cells.
*e.g s macrophage-CSF (M-CSF),
granulocyte-CSF (G-CSF, granulocyte and macrophage (GM-CSF).
example, M-CSF stimulates the production of monocytes from the bone
marrow, and subsequently their differentiation into macrophages once the
monocytes migrate into the tissues.
e) Chemokines affect leukocyte movement and attract various leukocyte
subsets, such as neutrophils, monocytes and lymphocytes, for example,
monocyte chemotactic protein-1 (MCP-1) attracts monocytes and IL-8
attracts neutrophils