[PDF][PDF] CRISPR/Cas9 screens reveal Epstein-Barr virus-transformed B cell host dependency factors

Y Ma, MJ Walsh, K Bernhardt, CW Ashbaugh… - Cell host & …, 2017 - cell.com
Y Ma, MJ Walsh, K Bernhardt, CW Ashbaugh, SJ Trudeau, IY Ashbaugh, S Jiang, C Jiang
Cell host & microbe, 2017cell.com
Epstein-Barr virus (EBV) causes endemic Burkitt lymphoma (BL) and immunosuppression-
related lymphomas. These B cell malignancies arise by distinct transformation pathways and
have divergent viral and host expression programs. To identify host dependency factors
resulting from these EBV+, B cell-transformed cell states, we performed parallel genome-
wide CRISPR/Cas9 loss-of-function screens in BL and lymphoblastoid cell lines (LCLs).
These highlighted 57 BL and 87 LCL genes uniquely important for their growth and survival …
Summary
Epstein-Barr virus (EBV) causes endemic Burkitt lymphoma (BL) and immunosuppression-related lymphomas. These B cell malignancies arise by distinct transformation pathways and have divergent viral and host expression programs. To identify host dependency factors resulting from these EBV+, B cell-transformed cell states, we performed parallel genome-wide CRISPR/Cas9 loss-of-function screens in BL and lymphoblastoid cell lines (LCLs). These highlighted 57 BL and 87 LCL genes uniquely important for their growth and survival. LCL hits were enriched for EBV-induced genes, including viral super-enhancer targets. Our systematic approach uncovered key mechanisms by which EBV oncoproteins activate the PI3K/AKT pathway and evade tumor suppressor responses. LMP1-induced cFLIP was found to be critical for LCL defense against TNFα-mediated programmed cell death, whereas EBV-induced BATF/IRF4 were critical for BIM suppression and MYC induction in LCLs. Finally, EBV super-enhancer-targeted IRF2 protected LCLs against Blimp1-mediated tumor suppression. Our results identify viral transformation-driven synthetic lethal targets for therapeutic intervention.
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