Fig. 1

Expression of biologically-active human interferon α2a by transgenic hens a Schematic representation of the interferon α2a transgene; ovalbumin regulatory elements including the estrogen response element (ERE) and the steroid-dependent regulatory element (SDRE); lysozyme signal peptide (LSP) for secretion; the coding sequence of human interferon α2a; EIAV long terminal repeats (LTR). b Western blot of dilutions of transgenic egg white protein (lanes 1 and 2) and 5 μg of commercially-available interferon α2a protein (lane 3), stained with antibody for human interferon α2a. c Activity of whole egg white assayed for activation of the interferon-stimulated response element (ISRE) by measurement of luciferase. Egg white from transgenic hens was compared with egg white with a range of concentrations of control protein added, and wild type egg white as a negative control. Measurements were taken in triplicate. Graph shows mean + SEM. d Interferon α2a was purified from egg white and confirmed by reducing SDS-PAGE Instant Blue staining. e SDS-PAGE of 5 μL samples of egg white before ovomucin precipitation (lane 1), pellet after first centrifugation (lane 2), supernatant after first centrifugation (lane 3), pellet after pH adjustment and second centrifugation (lane 4), and supernatant after pH adjustment and second centrifugation (lane 5); and western blot of 10 μL samples from each stage of purification: Blue Sepharose load (lane 6), Blue Sepharose flow-through (lane 7), Blue Sepharose wash (lane 8), Blue Sepharose eluate (lane 9) and final pure protein (lane 10). f Purified interferon α2a from egg white and a purchased control protein were tested in a viral dose-inhibition assay against influenza A virus. Measurements were taken in triplicate. Graph shows mean ± SEM