Recreating the genetic events of lymphomagenesis in primary human germinal center B-cells

Recent genomic studies of non-Hodgkin lymphoma have identified hundreds of recurrently altered genes. Notably, it remains largely unknown whether and how each of these mutations contributes to the pathogenesis of lymphoma, either individually or in combination. Existing strategies to address this problem predominantly utilize cell lines, which are poorly reflective of primary tumor cells due to adaptions to extensive in vitro culture. Here we describe a novel co-culture system that allows the ex vivo expansion, viral transduction and transformation of primary human germinal center B cells into high-grade B cell lymphomas. Using a backbone of BCL2 and BCL6 overexpression, we identified cooperative oncogenes required for cellular transformation into DLBCL. The application of CRISPR/Cas9 technology to these synthetically engineered high grade lymphomas allows to functionally interrogate gene mutations recurrently found in DLBCL. These tumors can be expanded and sequentially transplanted in vivo, providing a high-throughput screening platform for putative oncogenes and tumor suppressors and for the creation of mutation-directed, preclinical lymphoma models.