Fig. 4

PLD4 + blasts can differentiate into antibody-secreting cells and produce autoantibodies. A Plasmablasts and PLD4 + blasts were sorted and directly seeded onto PVDF membrane, followed by IgG ELISpot. B CD19 + B cells and PLD4 + blasts were sorted from two patients with SLE and cultured in vitro with TLR7 or TLR9 ligands for 4 days. The representative ELISpot results are shown in the pictures in the upper row and the measured number of spots are shown in the graph in the lower row. C The bar graphs show OD450 readings generated by antinuclear antibody enzyme-linked immunosorbent assay (ELISA). Each sample was tested in duplicate. I = VH1-18–01 J + KV 1–16-02, II = VH4-34–01 + KV 2–30-02, and III = VH1-18–01 + KV 1–5-03. IV represents randomly amplified monoclonal antibody from one healthy donor. V, serum from a healthy donor. VI, serum from a patient with SLE. ND, not detected