High efficient mammalian expression and secretion of a functional humanized single-chain Fv/human interleukin-2 molecules

Figure 1 Western blot analysis of recombinant humanized sFv antibody/IL-2 fusion proteins stably expressed in 293 cells. Lane A: 0.5 μg of rhIL 2; Lanes B, C, D and E: The supernants from conditioned medium of 293 cells, 293 cells transfected with pcDNA-H520C9sFv-hIL-2, pcDNA3.1 (+) and pcDNA-H520C9sFv-mhIL-2, respectively. Samples were separated on a 15% SDS-polyacrylamide gel under reducing conditions, transferred to nitrocellulose membranes and immunoblotted using the anti-human IL-2 polyclonal antibody, EP100. The fusion proteins, H520C9sFv-hIL-2 and H520C9sFv-mhIL-2 were shown to migrate as single bands of 45 kD.