Fig 4. Cul4b regulates pathogenicity of CD4⁺ T cells.

Each Rag1^−/− recipient mice was adoptively transferred with 1x10⁶ CD4⁺CD25⁻CD44⁻CD62L^hi naive T cells isolated from control and Cul4b^fl/fl-CD4Cre mice. (A) The weight loss of the mice was monitored every 7 days for 6–7 weeks from the day after intraperitoneal injection. n = 5, recipient mice for each group were used and experiment was repeated twice. (B) The distribution of CD4⁺ T cell populations in the spleen and colon of Rag1^−/− mice which received control (Cul4b^fl/fl) and Cul4b^fl/fl-CD4Cre CD4⁺ T cells was assessed by flow cytometry. (C) The bar graphs show the percentage and numbers of CD4⁺ T cells in the spleen and colon of Rag1^−/− recipient. Data are represented as mean ± SEM and are representative of one of the 2 experiments (n = 5) (*P < 0.05 **P < 0.01, ***P < 0.001 by Student t test). (D) Representative H&E staining of colon sections from Rag1^−/− mice transferred with control naive CD4⁺ T cells or Cul4b^fl/fl-CD4Cre naïve CD4⁺ T cells, (magnification 10×, scale bar 100 μM). (E and F) CD4⁺ T cells in spleen and colon were analyzed for Ki67 expression. Representative plots show the frequencies of Ki67-positive cells in recipients that received control or Cul4b^fl/fl-CD4Cre CD4⁺ T cells. The bar graphs show the relative frequencies of Ki67⁺CD4⁺ T cells in spleen and colon. (*P < 0.05, ***P < 0.001 by Student t test). For numerical raw data, please see S4 Data. Cul4b, Cullin-4b; SEM, standard error of mean.