Analysis of B-lineage development in recipients of a secondary transplant. Representative data from 1 of 3 experiments showing the following. (A) Peripheral blood collected from recipients of a secondary transplant 6 weeks after transplantation and stained for B220, IgM, and IgD. B220+ cells, presented as percentages of total peripheral blood mononuclear cells, are shown in the upper panel (IgM/B220, gated on live cells). Fraction F subsets, presented as percentages of total B220+ B cells, are shown in the lower panel. (B) Serum IgM, IgG3, and TNP-specific IgM for TNP-immunized, individual, recipients of a secondary transplant from the same experiment. TNP-specific IgG3 from week 12 is also shown. Combined data from all 3 experiments demonstrated a statistically significant increase in the total number of IgM+/B220+ B cells in MBS-treated mice (P < .01). These data suggest that Btk-dependent B-cell development and function are preserved in secondary MBS recipients.
