Genetic modification of primary human B cells generates translationally-relevant models of high-grade lymphoma

Sequencing studies of Diffuse Large B Cell Lymphoma (DLBCL) have identified hundreds of recurrently altered genes. However, it remains largely unknown whether and how these mutations may contribute to lymphomagenesis, either individually or in combination. Existing strategies to address this problem predominantly utilize cell lines, which are limited by their initial characteristics and subsequent adaptions to prolonged in vitro culture. Here, we describe a novel co-culture system that enables the ex vivo expansion and viral transduction of primary human germinal center B cells. The incorporation of CRISPR/Cas9 technology enables high-throughput functional interrogation of genes recurrently mutated in DLBCL. Using a backbone of BCL2 with either BCL6 or MYC we have identified co-operating oncogenes that promote growth and survival, or even full transformation into synthetically engineered models of DLBCL. The resulting tumors can be expanded and sequentially transplanted in vivo , providing a scalable platform to test putative cancer genes and for the creation of mutation-directed, bespoke lymphoma models.