Characterization of Type-I IFN subtype autoantibodies and activity in SLE serum and urine.

Background/objective: Type-I interferons contribute to pathogenesis in systemic lupus erythematosus, including nephritis. Interferons consist of a family of 16 proteins yet are often characterized in patients without knowledge of the specific interferon subtypes involved. Different interferons may function in the kidneys, and other organs, relative to what is often measured in patient blood.

A panel of synthetic antibodies that selectively recognize and antagonize members of the interferon alpha family.

The 12 distinct subtypes that comprise the interferon alpha (IFNα) family of cytokines possess anti-viral, anti-proliferative and immunomodulatory activities. They are implicated in the etiology and progression of many diseases, and also used as therapeutic agents for viral and oncologic disorders. However, a deeper understanding of their role in disease is limited by a lack of tools to evaluate single subtypes at the protein level.

Cytokine Activation by Antibody Fragments Targeted to Cytokine-Receptor Signaling Complexes.

Exogenous cytokine therapy can induce systemic toxicity, which might be prevented by activating endogenously produced cytokines in local cell niches. Here we developed antibody-based activators of cytokine signaling (AcCS), which recognize cytokines only when they are bound to their cell surface receptors. AcCS were developed for type I interferons (IFNs), which induce cellular activities by binding to cell surface receptors IFNAR1 and IFNAR2.

Production and characterization of thirteen human type-I interferon-α subtypes.

Thirteen human interferon-α (IFNα) subtypes were expressed in Escherichiacoli and purified using an N-terminal affinity tag from the prodomain of subtilisin. IFNα subtypes were expressed in soluble form and purified from cell lysates or refolded and purified from inclusion bodies. Proteins produced by either protocol exhibited biological activities equal to or greater than commercially prepared IFNα preparations.