A novel iPSC model of isogenic knockout of entire WAS gene can recapitulate WAS phenotypes in iPSC derived macrophages

Abstract

A novel iPSC model of isogenic knockout of entire WAS gene can recapitulate WAS phenotypes in iPSC derived macrophages Baolei Yuan1, Xuan Zhou1, Gerardo Ramos-Mandujano1, Lorena V. Cortes-Medina2, Chongwei Bi1, Mo Li1

Wiskott-Aldrich syndrome (WAS) is an X-linked recessive disease caused by mutations in the WAS protein (WASP). WAS is associated with devastating symptoms including microthrombocytopenia, eczema, autoimmunity and cancer. The molecular mechanism underlying WAS remains elusive thus far.

The genotype-phenotype relationship in WAS is complex. There are over 200 mutations that lead to hypomorphic levels or complete loss of WASP, while it is impossible to predict clinical severity based on the mutation alone. To help evaluate phenotype variability due to mutational background of different patients, we developed an isogenic WASP-knockout (WASP-KO) induced pluripotent stem cell (iPSC) model using the CRISPR/Cas9 technique that completely removed the WAS gene. The isogenic iPSC model was differentiated into macrophages, which are reported to be affected by WASP mutations. This model can be used for studying the WASP functions, WAS disease mechanism and drug screening.