Extended Data Fig. 8: PICALM-CRISPRa rescues the LD accumulation and phagocytosis-deficiency in LOAD risk-allele iMG.

(a) Representative fluorescence images show time-dependent phagocytosis of Aβ-pHrodo and LD accumulation (BODIPY⁺) in iMG carrying the LOAD risk-allele or non-risk allele and in risk-CRISPRa of PICALM. RFP+, iMG infected with pLenti-CRISPRa (note that both non-risk and risk control iMG also contain pLenti-CRISPRa that encodes RFP). Scale bar, 100 μm. (b) PICALM-CRISPRa rescues the LD accumulation in iMG carrying the LOAD risk-allele to a level similar to that in MG carrying the non-risk allele for both CD04 and CD09. Each datapoint represents a single-well measurement from one experiment; for each cell line (CD04 and CD09) and condition (non-risk, risk-allele and risk-CRISPRa), data are from one clone (per line), collected from 2 independent experiments each with 3 wells of differentiations (n = 6). One-way ANOVA with experimental round as the random factor; Dunnett’s correction. * P < 0.05, ** P < 0.01, ***, P < 0.001; mean ± s.e.m. (c) Pie charts depict the proportion of iMG stained positive for Aβ-pHrodo, BODIPY, or both from co-localization analysis of the fluorescence images in (a). Note the Aβ-pHrodo⁺/BODIPY⁺ iMG are rare, and PICALM-CRISPRa rescues the phagocytosis deficit in LOAD risk-allele iMG by mainly converting BODIPY⁺ iMG to phagocytic cells without LD (Aβ-pHrodo⁺/BODIPY⁻).