(A) Cellular extracts from 9 B cell lymphoma cell lines were immunoblotted with the indicated antibodies. (B) DOHH2 cells were transfected with control luciferase shRNA (shLuc), PELI1 shRNA (shPELI1; targeting PELI1 ORF), or 3′ untranslated region PELI1 shRNA (3′UTR; targeting PELI1 3′UTR) encoding construct in combination with the GFP or GFP-PELI1 expression plasmid, and SU-DHL4 cells were transfected with the pMyc or pMyc-PELI1 expression plasmid in combination with the shLuc or 3′UTR encoding construct. (C) HeLa cells were transfected with control pMyc, pMyc-PELI1-FL, or pMyc-PELI1-ΔC and HA-BCL6. At 24 hours after transfection, cells were cultured in the presence of LPS, further treated with cycloheximide (CHX), and lysed at the indicated times. (D) Splenic B220⁺ cells were isolated from non-Tg and PELI1-Tg mice and maintained in the absence or presence of LPS. At 24 hours after treatment, splenic B220⁺ cells were lysed and subjected to immunoblotting. In B–D, expression levels relative to the respective control are shown below blots. (E) B220⁺ cells were isolated from BM, LNs, and spleen of non-Tg and PELI1-Tg mice and maintained in the presence of LPS. B220⁺ cells were subjected to the intracellular staining of BCL2^hi cells and BCL6^hi cells. Gray area indicates isotype control staining. (F) Quantification of the BCL6^hi cell population in the BM, LNs, and spleen by intracellular staining of non-Tg and PELI1-Tg mouse–derived B220⁺ cells. Data (mean ± SEM) are representative of 2 experiments with 3 mice per experiment. ***P < 0.001.