B cell-specific PP4 deficiency reduces Ig production <i>in</i><i>vivo</i>.

<p>(<b>A</b>) Quantitation of serum levels of the indicated classes of Igs in non-immunized WT and CD23^crePP4^F/F mice (n = 8–10/group). Data are values for individual mice, and horizontal bars are geometric means. Results shown are from one experiment. (<b>B, C</b>) Quantitation of serum levels of TNP-specific IgG₁ (<b>B</b>) and IgG₃ (<b>C</b>) in WT and CD23^crePP4^F/F mice (n = 5–6/group) before immunization (d0), or at days 7, 14, 21, 35 and 49 post-immunization with TNP-KLH. Data are presented as in (A) and are from one experiment. (<b>D</b>) FACS profiles of CD38 vs IgG₁ and CD38 vs IgG₃ expression by B220⁺PNA⁻IgM⁻IgD⁻ gated splenocytes isolated from WT or CD23^crePP4^F/F mice (n = 3–6/group) at day 7 post-injection of PBS (control; left panels) or TNP-KLH (right panels). (<b>E</b>) Quantitation of the percentages of IgG₁⁺ (left) and IgG₃⁺ (right) switched B cells among total B cells from the mice in (D). Data are values for individual mice, and horizontal bars are geometric means. For (D–E), results are representative of two independent experiments. (<b>F–H</b>) Quantitation of serum levels of TNP-specific IgM (<b>F</b>), IgG₁ (<b>G</b>) and IgG₃ (<b>H</b>) in WT and CD23^crePP4^F/F mice (n = 8/group) before immunization (d0), or at days 7, 14, 21 and 28 post-immunization with TNP-Ficoll. Data are presented as in (A) and are from one experiment.