CRISPR genome editing of human dendritic cells

Dendritic cells (DCs) are central regulators of both innate and adaptive immunity and as such play roles in processes ranging from antitumor immunity to regulation of host-microbiome communication at the intestinal mucosa. Despite this importance, there is no method to genetically manipulate human DCs, limiting our ability to probe the mechanisms by which DCs elicit specific immune responses and to deploy DCs for cancer immunotherapy. Here, we report a CRISPR/Cas9 genome editing method for human monocyte-derived DCs (moDCs), achieving a median knockout efficiency of >93% for >300 genes targeted with a library of predicted guide RNAs. Using this method, we perform focused genetic screens in moDCs, identifying mechanisms by which the human immune system tunes responses to lipopolysaccharides (LPSs) from the human microbiome and specific factors that confer inter-individual variation in LPS responsiveness.