Fig. 5.
Proliferation of human mesangial cells stimulated with fractions of native or heat-inactivated cord-blood serum supplemented with Gal-deficient IgA1 myeloma protein. Gal-deficient IgA1 (Mce) myeloma protein (80 μg) was added to 160 μl of native (filled circles) or heat-inactivated (empty circles) cord-blood serum. After overnight incubation at 4 °C to allow formation of immune complexes, the samples were fractionated on a calibrated Superose 6 column, and the resultant fractions were filter-sterilized and added to serum-starved human mesangial cells, and cellular proliferation was measured. Panel (a) shows relative cellular proliferation. Panel (b) shows IgA concentration and panel (c) the amount of IgG–IgA complexes in the collected fractions. V0, void volume. Results of one of the two experiments are shown.