Interferons

Interferons are immune cytokines that are classified, as type I, II, or III, according to the receptors through which they signal. Interferon (INF) family receptors have conserved cysteine residues and include the receptors for IFN-α, IFN-β, and IFN-γ.

 Fc receptors  Immune Cytokines  Immunoglobulins

Type

Receptor

Secreting cell / action

IFN type I

IFN-α (1, 2, 4, 5, 6, 7, 8, 10, a3, 14, 16, 17, 21), IFN-β (1, 3), IFN-κ, IFN-δ, IFN-ε, IFN-τ, IFN-ω (with pseudogenes), IFN-ζ (limitin)

IFN-α receptor (IFNAR)

IFNAR1 and IFNAR2 chains

plasmacytoid dendritic cells (pDCs) are the most potent producers of type I IFNs, but virtually all cells are capable of production of type I IFNs – lymphocytes (NK cells, B cells, T cells), macrophages, fibroblasts, endothelial cells, osteoblasts

IFN-β is expressed primarily in nonimmune cells, and and IFN-α primarily in leukocytes

IFN type II

single isotype IFN-γ

IFN-γ receptor (IFNGR)

IFNGR1 and IFNGR2

activated T cells, Th1 cells, and natural killer cells.

potentiates the effects of the type I IFNs, stimulates macrophages to kill engulfed bacteria, regulates Th2 response, regulation of immune response (IFN-γ production can lead to autoimmune disorders)

IFN type III

types IFN-λ1(IL29), IFN-λ2 (IL28A), IFN-λ3 (IL28B)

(originally called macrophage-activating factor)

IL10R2 (CRF2-4) plus IFNLR1 (CRF2-12)

IFN-λs induced by both type I and type III IFNs (belong to IFN-stimulated genes (ISGs))

induced after stimulation by viruses and display antiviral activity

IFN-λs are produced by plasmacytoid dendritic cells to a greater extent than by myeloid dendritic cells

specific interferons

actions

IFN-β1a (Avonex, Rebif) employed in treatment of multiple sclerosis (MS, DS)
IFN-β1b (Betaseron) employed in treatment of multiple sclerosis (MS, DS)

0 Comments:

Post a Comment

Links to this post:

Create a Link

<< Home

. . . since 10/06/06