Abcam, ab190383, Recombinant vaccinia virus B18R protein

Size: 25µg
Recombinant vaccinia virus B18R protein is a Vaccinia virus WR Fragment protein, in the 20 to 351 aa range, expressed in Escherichia coli, with >95%, < 1 EU/µL endotoxin level, suitable for SDS-PAGE, FuncS.
Key facts
Purity:>95% SDS-PAGE,
Endotoxin level:< 1 EU/µL,
Expression system:Escherichia coli,
Tags:His-T7 tag N-Terminus,
Applications:FuncS, SDS-PAGESee reactivity dataSee the reactivity data table below for information on validated species and application combinations.,
Biologically active:Yes,
Biological activity:Measured by neutralization of IFN-alpha effects on MCF7 cells in RT-PCR assay using IFN-alpha specific induced target gene index.,
Accession:P25213,
Animal free:No,
Carrier free:Yes,
Species:Vaccinia virus WR,
Storage buffer:pH: 8Constituents: 0.32% Tris HCl

Properties and Storage Information:
Shipped at conditions-Blue Ice, Appropriate short-term storage duration-1-2 weeks, Appropriate short-term storage conditions-+4°C, Appropriate long-term storage conditions--80°C, Storage information-Avoid freeze / thaw cycle

Supplementary Information:
This supplementary information is collated from multiple sources and compiled automatically.
The B18R protein also known as B18R interferon inhibitor is a viral protein that belongs to the family of poxvirus encoded immunomodulatory proteins. It has a molecular mass of approximately 43 kDa. The protein is expressed by the Vaccinia virus specifically within the extracellular environment. B18R interacts with the host's immune signaling pathways by binding to type I interferons which prevents them from interacting with their receptors effectively inhibiting the host's antiviral responses.
Biological function summary
B18R acts as an interferon inhibitor that neutralizes the activity of the host's type I interferon (IFN) responses to viral infection. This protein does not usually form part of a complex but functions independently in the extracellular space. By binding to the interferons it blocks their interaction with the interferon receptors on host cells which leads to a diminished antiviral state and allows viral replication to proceed without interruption. This function highlights its role in viral evasion of the host's immune defenses.
Pathways
B18R interferes with the interferon signaling pathway which is important for the establishment of an antiviral state in host cells. The protein directly impacts the JAK-STAT signaling pathway by preventing interferons from binding to their receptors blocking the downstream activation of STAT1 and STAT2 proteins. This interruption of the signaling sequence suppresses the expression of interferon-stimulated genes and impairs the innate immune response facilitating a more favorable environment for the virus.
B18R is mainly studied in the context of infections caused by poxviruses such as smallpox and monkeypox. By inhibiting the interferon response B18R allows these viruses to bypass the host's initial immune defenses contributing to the spread and severity of the infection. The protein's activity connects it to other viral inhibitors like E3L protein of the Vaccinia virus which also targets interferon pathways to subvert host immunity demonstrating a concerted viral strategy to evade host defenses.