Figure 5.

CD4⁺Ly108^hi iNKT cells provide help for spontaneous antibody secretion of B cells. Sorted B cells with or without sorted iNKT cells, were cultured for 10 days, then supernatant were collected for determination of IgM, IgG and IgG anti-dsDNA antibody concentrations. For IL-21 production assays, cells were sorted and cultured (5X10⁵/ml) for 3 days with anti-CD3 and CD28 mAbs. Different populations of iNKT cells were sorted from three pooled spleens of BW mice. (A) IgM, IgG and IgG anti-dsDNA antibody production from cultures of B cells, with or without sorted Ly108^hi or Ly108^lo iNKT cells from 6 month old BW mice. (B) IL-21 production by anti-CD3/CD28 stimulated iNKT and Tcon cells of young BW mice. (C) IgM, IgG and IgG anti-dsDNA antibody production from B cells cultures, with or without sorted CD4⁺Ly108^hi, CD4⁺Ly108^lo or CD4⁻Ly108^lo iNKT cells from 6 month old BW mice. (D) IL-21 production by sorted CD4⁺Ly108^hi, CD4⁺Ly108^lo or CD4- Ly108^lo iNKT from young BW mice. ND, Not Detected. *, P<0.05; **, P<0.01; ***, P<0.001 (two-tailed Student’s t-test). Data (mean ± s.e.m.) shown are derived from three or four independent experiments (B, D) or from triplicate collected from one representative experiment of two to five with similar results (A, C)