Fig 4.

Autoantibodies in IgM memory B cell subsets. (a) Antibodies cloned from IgM memory B cells in HCV-infected donors that tested positive for nuclear antigens in the Hep-2 IFA stain. Four representative stains from antibodies isolated from healthy individuals are shown. (b) dsDNA ELISA results on IgM memory B cell antibodies from healthy (n = 25) and HCV-infected (n = 25) donors. The ANA and dsDNA reactive antibody 4E10 (red) is used for the positive control. The horizontal dotted line shows the cutoff OD₄₀₅ value for positive reactivity as determined by a comparison to negative-control plasma from healthy and HCV-infected donors. (c) V_H gene usage and CDRH3 characteristics, length (number of amino acids) and net charge (number of positively charged residues minus the number of negatively charged residues) of autoantibodies. CDRH3 regions from IgM memory B cells in healthy (n = 54) and HCV-infected (n = 61) donors were analyzed for length (d) and net charge (e) (healthy, blue shades; HCV+, red shades).