Figure 6. B cells are capable of degrading S1P.

(a) S1P1 surface abundance on follicular B cells from the indicated tissues of control (CTL), S1pr1-deficient (S1P1 KO), or Mx1-cre⁺Sphk1^{f/− or f/f}Sphk2^−/− (S1P-deficient) mice. Data are representative of more than 3 mice of each type. (b) Transcript abundance of S1P lyase (Sgpl), sphingosine-1-phosphate phosphatase-1 (Sgpp1), and lipid phosphate phosphatases (Lpp) 1–3 in B cells and T cells, shown relative to HPRT. (c) Relative amount of S1P remaining in culture supernatants after incubation with B or T cells for the indicated number of minutes, determined by the extent of down-modulation of Flag-S1P1 on a reporter cell line. Data are plotted as MFI of Flag-S1P1 staining relative to reporter cells not exposed to S1P (data are from 3 experiments).