Journal: The Journal of Immunology Author Choice
Article Title: Heme enhances B-cell proliferation and plasma cell formation through reduced p21 and Rb expression
doi: 10.1093/jimmun/vkag025
Figure Lengend Snippet: Heme represses the p21-Rb cell cycle regulatory axis. (A) Model depicting how p53, p21, and Rb function to regulate the G1 to S phase transition of the cell cycle under conditions of cell cycle arrest (left) or cell cycle progression (right). Naïve B cells were stimulated with CD40L, IL-4, and IL-5, and heme or vehicle control was added at 24 h. (B) Bar plot representing Trp53 transcript abundance at 54 h and 72 h measured by RT-qPCR. (C) Western blot for p53 protein and β-actin. Images for p53 protein were adjusted for brightness (+40%) and contrast (−40%). (D) Bar plot representing p53 expression relative to β-actin from (C). (E) Boxplot quantitating the ATAC-seq signal at p53 motifs in the indicated condition. (F) Genome plot of the Cdkn1a locus depicting the ATAC-seq signal and significant differential accessible region (box) in heme- vs vehicle-treated activated B cells (ActB) and plasma cells (PCs). The location of a previously identified p53 binding site is indicated in red. (G) Bar plot representing Cdkn1a transcript abundance at 54 h and 72 h measured by RT-qPCR. (H) Representative flow cytometry histogram showing intracellular staining for p21 protein in heme or vehicle control cultures after 72 h along with isotype staining and FMO controls. (I) Bar plot quantitating MFI of p21 expression from (H). (J) Representative flow cytometry histogram showing intracellular staining for Rb protein in heme or vehicle control cultures after 72 h along with isotype staining and FMO controls. (K) Bar plot quantitating MFI of Rb expression from (J). Data represent the combination of at least 2 independent experiments with the indicated P value calculated with paired Student t- tests. FMO, Fluorescence Minus One; MFI, median fluorescence intensity; RPPM, reads per peak per million.
Article Snippet: B cells were stimulated with either 20 μg/mL LPS (L2630; Sigma), 20 ng/mL IL-2 (575406; BioLegend), and 5 ng/mL IL-5 (581504; BioLegend) or 500 ng/mL CD40L (R&D Systems, 8230-CL), 10 ng/mL IL-4 (R&D Systems, 404-ML), and 10 ng/mL IL-5.
Techniques: Sublimation, Control, Quantitative RT-PCR, Western Blot, Expressing, Clinical Proteomics, Binding Assay, Flow Cytometry, Staining, Fluorescence