Vaccinia Virus B18R Proteins

Protein Information

The B18R protein is a vaccinia virus-encoded receptor with specificity for mouse, human, rabbit, pig, rat, and cow type I interferons which has potent neutralizing activity.B18R that acts as a decoy receptor for Type I Interferons (IFNa, IFNb, IFNe,k,t,d,z, w,v). B18R was recently identified to enable increased cell viability during RNA transfection protocols designed to convert human somatic donor cells into iPSCs via direct delivery of modified synthetic mRNAs for OCT4, SOX2, KLF4 and MYC (OSKM) and Lin28 with the aim to enable highly efficient reprogramming of somatic cells to pluripotency. This allows for re-directed differentiation toward a desired lineage while removing the risk of genomic integration and insertional mutagenesis inherent to DNA-bases methodologies and eliminates the need for virus-based approaches. iPSCs represent a widely available, non-controversial and practically infinite source of pluripotent cells.The B18R protein is a type I interferon receptor encoded by the B18R gene of the Western Reserve vaccinia virus strain. The 60-65 kD glycoprotein is related to the interleukin-1 receptors and is a member of the immunoglobulin superfamily, unlike other type I IFN-receptors, which belong to the class II cytokine receptor family. The B18R protein has a high affinity (KD, 174 pM) for human IFN alpha and, unlike other type I IFN receptors, has broad species specificity, binding to type I interferons of human, mouse, rat, rabbit, pig, and cow. Among viral host response modifiers, the B18R protein is unique in that it exists as a soluble extracellular, as well as a cell surface protein, enabling blockage of both autocrine and paracrine IFN functions. The B18R protein has been shown to inhibit the antiviral potency of IFN-alpha1, IFN-alpha2, IFN-alpha-8/1/8, and IFN-omega on human cells. The soluble B18R protein is highly potent for neutralizing type I interferons, which include IFN-alpha, beta, delta, kappa. Please note effects on mouse IFNs vary from other species; it has been shown that B18R does not neutralize mouse IFN beta.