Figure 8.

Itch limits proliferation and mTORC1 in B cells in vivo. (A) Experimental design for B and C. Lambda⁺ B cells were isolated from WT and Itch KO B1-8 mice (CD45.2). Cells were labeled with CellTrace and transferred into WT recipient mice (B6.SJL CD45.1), which were then immunized with NP-OVA in alum. (B) On day 3, CellTrace dye dilution of spleen NP⁺CellTrace⁺CD45.2⁺ cells was analyzed. (C) P-S6 MFI of NP⁺CellTrace⁺CD45.2⁺ cells after 1 h culture at 37°C in B cell media was determined by flow cytometry. Fold change refers to KO/WT MFI (for B and C: n = 6 or 7, three independent experiments, unpaired t test). (D) Experimental design for E and F. (E and F) Spleen cells were harvested on day 12 after immunization. (E) CellTrace dye dilution of spleen NP⁺CellTrace⁺CD45.2⁺ cells was analyzed. (F) P-S6 MFI of NP⁺CellTrace⁺CD45.2⁺ spleen B cells after 1 h culture at 37°C in B cell media was determined by flow cytometry. Fold change refers to KO/WT MFI (for E and F: n = 5, two independent experiments, unpaired t test). Error bars indicate SEM; *, P < 0.05.