Figure 5.
S729A B cells respond to LPS or CpG-1826 stimulation by producing XBP1s. (A) Naive WT and S729A B cells were stimulated with LPS (20 µg/ml) for a course of 3 d and immunoblotted. (B) Naive WT B cells were stimulated with LPS or CpG-1826 (0.5 µM) for a course of 3 d, stained for XBP1s and B220, and analyzed for gated B220+/XBP1s+ populations. (C) B cells purified from WT and S729A mice were stimulated with LPS for 1 d and continued to be stimulated with LPS for an additional 3, 6, 12, and 24 h (the end of day 2). At each time point, B cells were stained for XBP1s and B220 and were analyzed for gated B220+/XBP1s+ populations. Flow cytofluorometric data are representative of three independent experiments. (D) Naive B cells purified from WT (n = 3) and S729A (n = 3) mice were stimulated with LPS for 1 d and continued to be stimulated with LPS for an additional 3, 12, and 24 h. At each time point, B cells were stained with XBP1s–Alexa Fluor 647 and B220–Alexa Fluor 488. The gated B220+ populations were analyzed for expression of XBP1s shown as MFI (means ± SD). The MFI data are representative of three independent experiments.