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<Structure load='Insert PDB code or filename here' size='500' frame='true' align='right' caption='Insert caption here' scene='56/566498/Interferon_beta_1a/1' />

=='''IFN Categories and IFNβ-1a sources'''==

Interferons (IFNs) are a family of helical cytokines that mediate
antiviral, antiproliferative, and immune modulatory activities in
response to biological and chemical stimuli. Two types of IFN are recognized on   
the basis of their physical and biological properties; type I, which   
contains the monomeric IFNs-α,-β,-τ, and -ω, and type II, the
only member of which is the dimeric IFN-γ. Representatives of all
type I and type II IFNs are found in humans, except for IFN-τ,
which is found only in ruminant ungulates. There are 12 different human IFNs-α;each one
comprising a different subtype,although 14 different genes have
been identified, whereas human IFN-β, IFN-ω, and IFN-γare
encoded by single genes[1].

Interferon-βhas two subtyes, interferon-β-1a and interferon-β-1b. Interferon-β-1a is naturally expressed in numerous cell types in human, including 
fibroblasts, endothelial cells, epithelial cells and various leukocytes, however,Interferon-β-1b is produced in modified E. coli.

Here is a jpg clearly illustrating IFNs categories.
[[Image:IFN categories.jpg]]

=='''Structure info. of IFNβ-1a'''==
IFNβ-1a consisting of 166 amino acids, around 20KDa. It has 5 helixs.
<scene name='56/566498/Interferon_beta_1a/1'>Interferon beta 1a</scene>

=='''IFNβ-1a biological activity and therapeutic effects'''==

IFNβ-1a as well as other family of IFNs has a variety of biological activities, inluding antiviral, antiproliferative, and immune modulatory activities in response to biological and chemical stimuli[2]. 

IFNβ-1a is mainly used to treat relapsing forms of multiple sclerosis(MS).
MS is a life-long disease that affects your nervous system 
by destroying the protective covering (myelin) that surrounds
your nerve fibers.
The commercial available drug format is [http://http://www.avonex.com/ Avonex].(Please refer to the drug guide before using it)

=='''Mechanism of action for IFNβ-1a'''==

'''The IFNβreceptor, signaling cascade and gene regulation'''

The IFNβreceptor is composed of 2 required chains—a signaling
chain,<scene name='56/566498/Human_ifnar1/1'>IFNAR1</scene> , and a binding chain, <scene name='56/566498/Ifnar2/1'>IFNAR2</scene>. Both IFNAR1 and
IFNAR2 are constitutively expressed on the surface of virtually all cells. IFNβcan bind to IFNAR2 alone, but can bind to IFNAR1 only in
the presence of IFNAR2. The strength of IFNβbinding to its
receptor is much higher when both subunits are present.
Knockout experiments indicate that both IFNAR1 and IFNAR2 are
required for IFNβ activity, but it remains uncertain
whether there are auxiliary receptors or alternative receptor/
signaling complexes in some cell types.
The current view of events leading to IFNβbiological activity is
as follows: 1) IFN binds to the extracellular domain of
IFNAR2. 2) IFNAR1 then engages with the IFNβ–IFNAR2 complex,
forming the high-affinity receptor–ligand complex and allowing
the intracellular domains of the two receptor chains and
associated proteins to interact. 3) This interaction, which includes
JAK1 (associated with IFNAR2) and Tyk2 (associated with IFNAR1),
results in a cascade of phosphorylation events that leads to
activation of STATS. 4) Activated STATS form a complex with other
cytoplasmic proteins, which then translocate into the nucleus to
bind to Interferon Sensitive Response Elements (ISRE), transcriptional control regions which are upstream of many IFN regulated
genes. 5) This ISRE binding results in transcriptional regulation
(both induction and inhibition) of >1000 genes.
Thus, IFN regulates expression of a myriad of genes. While the
function of some of these genes is clear (e.g. the antiviral product
MxA), the specific transcripts mediating therapeutic benefit of
IFNβin MS are unknown. This is, in part, due to the complexity and
heterogeneity of MS, but also because IFNβis an agonist that can
induce the expression not only of ISRE regulated genes, but
through newly expressed transcription factors, can induce or
inhibit subsequent waves of gene expression. In addition, some
IFNβregulated proteins, which include cytokines and chemokines,
can alter the level or function of particular cell populations. The
resulting multifaceted biological response is in contrast to
therapies such as monoclonal antibodies that have a much more
specific molecular target[2-9].

=='''Reference'''==

[1] R. Arduini, K. Strauch, L. Rukel etal.Characterization of a soluble ternary complex formed
between human interferon-b-1a and its receptor chains''Protein Science'' (1999),''8'':1867–1877

[2] T. Taniguchi, A. Takaoka, The interferon-alpha/beta system in
antiviral responses: a multimodal machinery of gene regulation
by the IRF family of transcription factors, Curr. Opin. Immunol.
14 (1) (Feb 2002) 111–116.

[3] K. Kasama, J. Utsumi, E. Matsuo-Ogawa, T. Nagahata, Y. Kagawa,
S. Yamazaki, et al., Pharmacokinetics and biologic activities of
human native and asialointerferon-beta s, J. Interferon Cytokine
Res. 15 (5) (May 1995) 407–415.

[4] L. Runkel, W. Meier, R.B. Pepinsky, M. Karpusas, A. Whitty,
K. Kimball, et al., Structural and functional differences between
glycosylated and non-glycosylated forms of human
interferon-beta (IFN-beta), Pharm. Res. 15 (4) (Apr 1998)
641–649.

[5] R.M. Arduini, K.L. Strauch, L.A. Runkel, M.M. Carlson, X.
Hronowski, S.F. Foley, et al., Characterization of a soluble
ternary complex formed between human interferon-beta-1a
and its receptor chains, Protein Sci. 8 (9) (Sep 1999)
1867–1877.

[6] G. Uze, G. Schreiber, J. Piehler, S. Pellegrini, The receptor of the
type I interferon family, Curr. Top. Microbiol. Immunol. 316
(2007) 71–95.

[7] C.M. Cleary, R.J. Donnelly, J. Soh, T.M. Mariano, S. Pestka,
Knockout and reconstitution of a functional human type I
interferon receptor complex, J. Biol. Chem. 269 (29)
(Jul 22 1994) 18747–18749.

[8] J. Kumaran, O.R. Colamonici, E.N. Fish, Structure–function study
of the extracellular domain of the human type I interferon
receptor (IFNAR)-1 subunit, J. Interferon Cytokine Res. 20 (5)
(May 2000) 479–485.

[9] J. Ghislain, G. Sussman, S. Goelz, L.E. Ling, E.N. Fish, Configuration
of the interferon-alpha/beta receptor complex determines the
context of the biological response, J. Biol. Chem. 270 (37)
(Sep 15 1995) 21785–21792.