Development of a Recombinant Cell-Based Indirect Immunofluorescence Assay for the Determination of Autoantibodies against Soluble Liver Antigen in Autoimmune Hepatitis

Figure 1

Characterization of recombinant SLA proteins by SDS-PAGE and westernblot. (a) Bacterially expressed SLA was analyzed by SDS-PAGE with coomassie staining. Lane 1: molecular mass markers, kDa indicated; lane 2: 2 μg recombinant SLA, arrow heads indicate the presence of anti-His-Tag antibody reactive SLA-fragments verified by mass spectrometry, (b) 1 μg/lane recombinant SLA purified from E. coli, (c) or cell-free supernatant from HEK293 expressing SLA; lane 1: murine monoclonal antibody against hexahistidine; lanes 2: rabbit polyclonal serum against SLA; lanes 3–7: anti-SLA positive sera from patients with autoimmune hepatitis (AIH); lanes 8–12: anti-SLA negative sera from patients with AIH; lanes 13–17: sera from healthy blood donors; the band in c, lane 15 does not correspond to SLA.