Fig. 5. Deficiency of Tnfα in B-ALL cells prolongs survival.
a Number of primary murine BCR-ABL1+ BP-1+ B-ALL cells which migrated from the upper chamber through a layer of wild type (black), MMP-9 KO (white), or tumor necrosis factor receptor (TNFR)-1 KO (gray) MSC to the lower chamber in a transwell–invasion assay, which contained 500 ng/ml CXCL13 (P value as indicated; ANOVA, Tukey test, n = 4–6). 105 leukemia cells had been plated and were allowed to migrate for 24 h. b Representative immunofluorescence images of MSC after 8 h of treatment with vehicle (top) or Tnfα (bottom), stained with an antibody to phospho P65 (red) and DAPI (blue). The scale bar depicts 50 μm in all images and 25 μm in the magnified images (extreme right panel). n = 9–10. The images are representative of two independent experiments. c Binding of P65 to the Mmp9 promoter in MSC treated with vehicle or 15 ng/ml Tnfα for 6 h, as measured by a ChIP assay using an anti-P65 (white) or a control IgG (black) antibody and two different primer pairs (P1 and P2) for Mmp9 (P = 0.05, t test, n = 3). d Kaplan–Meier-style survival curve for wild type C57/Bl6 recipients of BCR-ABL1-transduced bone marrow cotransduced with scrambled shRNA- (solid line) or Tnfα shRNA-expressing lentivirus (dashed line) in the B-ALL model (P = 0.03, Log-rank test, n = 5).