FIG. 7.
Secretion of autoantibodies from purified B cells stimulated with purified H. pylori urease. A total of 106 of the purified splenic B cells were cultured with 10-μg/ml purified H. pylori urease or PBS for 3 to 7 days, and the supernatants were harvested to test autoantibody production by enzyme-linked immunosorbent assay. (A) A significant amount of IgG3, the dominant substance of B-1 cells, was produced in the culture supernatants compared with PBS. In comparison with the control supernatants stimulated with PBS, >1,000 mU of IgM type RFs/ml (B), as well as anti-ssDNA antibody (C) and anti-PC antibody (D), were detected in the culture supernatants stimulated with H. pylori urease for 7 days. Data shown are representative of three independent experiments.