Fig. 4: Murine CLL cells with disrupted NFKBIE are positively selected by the tumor microenvironment in vivo.

A TCL1-355-TKO NFKBIE-ko and NFKBIE-wt cells were mixed at a 1:2 ratio and injected in 4 C57BL/6 mice (2 × 10⁷ cells/mouse). Cells were isolated from the PC, peripheral blood (PB) and spleen of the injected C57BL/6 mice 3 weeks after adoptive transfer and NFKBIE MAF was determined in purified leukemia cells by amplicon capillary electrophoresis of the targeted region. Statistical analysis was done using One-way Repeated Measures ANOVA with the Holm-Sidak test for multiple comparisons. B NFKBIE MAF in injected leukemia cells and cells isolated from the PC and spleen of NSG mice 3 weeks after transplantation. The TCL1-355-TKO NFKBIE-ko and NFKBIE-wt cells were mixed at a 1:2.5 ratio and injected in 5 NSG mice (2 × 10⁷ cells/mouse). Statistical analysis was done as above. C In vivo BrdU-incorporation analysis of TCL1-355 TKO NFKBIE-wt or NFKBIE-ko cells isolated from PC and spleen of NSG mice (n = 4/group). BrdU was injected intraperitoneally 21 days after adoptive transfer. Leukemic cells were collected after 12 h, purified by negative selection using a B cell isolation kit, and analyzed by flow cytometry. Flow charts show the analysis of one NFKBIE-wt and one NFKBIE-ko sample, summary of the data is shown in the graph. Statistical analysis was performed using the Mann–Whitney Rank Sum Test.