Most mammalian species have multiple IFN-a subtypes.
Although the reasons for these multiple subtypes are not fully known, there are clear cell type and temporal differences in their expression.
A recent study established a nomenclature for the murine IFN-a subtypes (van Pesch et al.
2004) and determined relative activities of the subtypes with protein quantification by phosphorimaging of metabolically-labeled protein.
In this study, Mu IFN-a4 was deemed to have average antiviral activity when compared with the potency of the other subtypes.
Mu IFN-a4 was initially cloned by Zwarthoff et al.
[(1985) Nuc.
Acids Res.
13(3) 791], and has been extensively studied.
It is apparently expressed early in viral infection in a protein synthesis independent manner, and its expression is induced by phosphorylation of IRF-3.
It may be that Mu IFN-a4, like IFN-b, has a priming function on cells, enabling the expression of other Mu IFN-a subtypes [Reviewed by Mesplède et al.
(2003) Autoimmunity 36(8):447 and Asselin-Paturel & Trinchieri (2005) J.
Exp.
Med.
202(4):461].
Thus, this interferon is among the first observed after viral infection.
Intriguingly, while this interferon is expressed in a large variety of cell types, one report suggests that the expression level in dendritic cells is low to non-existent [Barchet et al.
(2002) J.
Exp.
Med.
195(4):507]
Applications:Suitable for use in Immunofluorescence and Western Blot.
Other applications not tested.
Recommended Dilution:Immunofluorescence: 10ug/mlOptimal dilutions to be determined by the researcher.
