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HEK-Blue IFN-a/b Cells - Human Type I IFN Reporter Cells
➥ Monitor the JAK/STAT/ISGF3 pathway
➥ Detection of human IFN-a and IFN-b
Background
Type I interferons, in particular interferon alpha (IFN-a) and interferon beta
(IFN-b), play a vital role in host resistance to viral infections. They signal
mainly through the JAK-STAT pathway. Following their production, IFN-a
and IFN-b bind to a common receptor (IFNAR) and recruit the Janus
kinases (JAK1 and TyK2). JAKs phosphorylate STAT1 and STAT2, which
then dimerize and interact with IFN regulatory factor 9 (IRF9), forming a
complex named ISGF3. ISGF3 binds to IFN-stimulated response elements
(ISRE) in the promoters of IFN-stimulated genes (ISG) to regulate their
expression (figure 1).
Description
HEK-Blue IFN-a/b cells allow the detection of bioactive human type I
IFNs by monitoring the activation of the ISGF3 pathway. These cells were
generated by stable transfection of HEK293 cells with the human STAT2
and IRF9 genes to obtain a fully active type I IFN signaling pathway. The
other genes of the pathway (IFNAR1, IFNAR2, JAK1, TyK2 and STAT1) are
naturally expressed in sufficient amounts. The cells were further transfected
with a SEAP reporter gene under the control of the IFN-a/b-inducible
ISG54 promoter.
Stimulation of HEK-Blue IFN-a/b cells with human IFN-a or IFN-b
activates the JAK/STAT/ISGF3 pathway and subsequently induces the
production of SEAP. Levels of SEAP in the supernatant can be easily
determined with QUANTI-Blue , a medium that turns purple/blue in the
presence of SEAP and by reading the OD at 655 nm (figure 2).
Stimulation of HEK-Blue IFN-a/b cells with recombinant human IFN-a
can be blocked by anti-hIFN-a-IgA, a neutralizing monoclonal antibody of
the IgA isotype (see page 104).
• Detection range for hIFN-a: 5 - 10 4 IU/ml
• Detection range for hIFN-b: 20 - 10 4 IU/ml
HEK-Blue IFN-a/b cells are resistant to blasticidin and Zeocin .
Contents and Storage
HEK-Blue IFN-a/b cells are grown in standard DMEM medium, 2mM
L-glutamine,10% FBS supplemented with blasticidin (30 μg/ml) and
Zeocin (100 μg/ml). Cells are provided frozen in a cryotube containing
5-7 x 10 6 cells and supplied with 100 μl of blasticidin at 10 mg/ml, 100 μl
of Zeocin at 100 mg/ml, 1 ml Normocin at 50 mg/ml, and 1 pouch of
QUANTI-Blue . Cells are shipped on dry ice.
PRODUCT QUANTITY CAT. CODE
HEK-Blue IFN-a/b cells 5-7x 10 6 cells hkb-ifnab
Figure 1: JAK-STAT pathway induced by type I IFNs.
Figure 2: Stimulation of HEK-Blue IFN-a/b cells by human IFN-a2b, IFN-b1a and
IFN-g was assessed by measuring the levels of SEAP using QUANTI-Blue .
Related Products
Blasticidin, page 17 Anti-hIFN-a-IgA , page 104
Zeocin , page 18 QUANTI-Blue page 14
www.invivogen.com/cytokine-sensor-cells 107
CYTOKINE SIGNALING 4