Functional Analysis and Transcriptomic Profiling of iPSC-Derived Macrophages and Their Application in Modeling Mendelian Disease
Rationale: An efficient and reproducible source of genotype-specific human macrophages is essential for study of human macrophage biology and related diseases.
Objective: To perform integrated functional and transcriptome analyses of human induced pluripotent stem cell-derived macrophages (IPSDM) and their isogenic PBMC-derived macrophages (HMDM) counterparts and assess the application of IPSDM in modeling macrophage polarization and Mendelian disease.
Methods and Results: We developed an efficient protocol for differentiation of IPSDM, which expressed macrophage-specific markers and took up modified lipoproteins in a similar manner to HMDM. Like HMDM, IPSDM revealed reduction in phagocytosis, increase in cholesterol efflux capacity and characteristic secretion of inflammatory cytokines in response to M1 (LPS+IFN-γ) activation. RNA-Seq revealed that non-polarized (M0) as well as M1 or M2 (IL-4) polarized IPSDM shared transcriptomic profiles with their isogenic HMDM counterparts while also revealing novel markers of macrophage polarization. Relative to IPSDM and HMDM of control individuals, patterns of defective cholesterol efflux to apoA-I and HDL3 were qualitatively and quantitatively similar in IPSDM and HMDM of patients with Tangier disease (TD), an autosomal recessive disorder due to mutations in ATP-binding cassette transporter A1. TD-IPSDM also revealed novel defects of enhanced pro-inflammatory response to LPS stimulus.
Conclusions: Our protocol-derived IPSDM are comparable to HMDM at phenotypic, functional and transcriptomic levels. TD-IPSDM recapitulated hallmark features observed in HMDM and reveal novel inflammatory phenotypes. IPSDM provide a powerful tool for study of macrophage-specific function in human genetic disorders as well as molecular studies of human macrophage activation and polarization.
- Received December 14, 2014.
- Revision received April 20, 2015.
- Accepted April 21, 2015.