Establishment of a human TLR4 compound heterozygous knockout hESC line (WAe009-A-N) to model toll-like receptor 4 deficiency by CRISPR/Cas9 system.

Toll-like receptor 4 (TLR4) is a pattern recognition receptor (PRRS) and an important protective immune receptor. TLR4 deficiency can lead to Inflammatory bowel disease. To explore the role of TLR4, we used CRISPR/Cas9 system to produce TLR4 compound heterozygous knockout embryonic stem cells in H9 cell line. The WAe009-A-N has a compound heterozygous 7 bp deletion/8 bp deletion in TLR4 exon 3, which resulted in a frameshift in the translation of TLR4, and TLR4 protein wasn't detectable in this cell line. In addition, the WAe009-A-N with normal karyotype can express pluripotent markers and differentiate into three germ layers in vitro.