CRISPR correction of GBA mutation in hiPSCs restores normal function to Gaucher macrophages and increases their susceptibility to Mycobacterium tuberculosis

Abstract

Gaucher disease (GD) is an autosomal recessive lysosomal storage disorder caused by mutations in the β-glucocerebrosidase (GCase) GBA gene, which result in macrophage dysfunction. To investigate whether correction of GBA mutations restores normal function to Gaucher macrophages, we performed CRISPR editing of homozygous L444P (1448T→C) GBA mutation in Type 2 GD (GBA-/-) hiPSCs, which yielded both heterozygous (GBA+/-) and homozygous (GBA+/+) isogenic lines. Macrophages derived from GBA-/-, GBA+/- and GBA+/+ hiPSCs, were compared for GCase enzymatic activity, motility, and phagocytosis, all of which showed that GBA mutation correction restores normal macrophage functions. Furthermore, we investigated whether lysosomal disorders drive susceptibility to Mycobacterium tuberculosis, by infecting GBA-/-, GBA+/- and GBA+/+ macrophages with the virulent H37Rv lab strain. The results showed that impaired mobility and phagocytic activity of Gaucher macrophages, correlated with reduced levels of TB engulfment and TB multiplication, supporting the hypothesis that GD may be protective against tuberculosis.