Efficient CRISPR-Cas ribonucleoprotein-based gene targeting of human alveolar type 2 cells.

Alveolar type 2 (AT2) cells play numerous roles in the alveolus related to stem cell, immunoregulatory, and secretory functions. Primary human AT2 cells can now be isolated and studied as organoids consisting of self-organizing epithelial tissues as pure populations without the need for stromal support cells. However, genetic manipulation of AT2 cells to investigate their biology has relied on expensive and time-consuming processes requiring the use of viral vectors or conducting gene editing with induced pluripotent stem cell-derived AT2 cells. Here we describe a high-efficiency method of accomplishing highly effective gene editing in cultured primary human AT2 cells, which can be done rapidly and at significantly lower costs. Using an optimized CRISPR ribonucleoprotein approach, we can achieve nearly complete genetic knockout while preserving AT2 identity and viability. Our results simplify the process of genetically manipulating human AT2 cells to better understand the role of the alveolar epithelium in human lung biology.