# Generation and characterization of iPSC‐derived microglia for in vitro modeling of stimuli‐specific neuroimmune responses **Authors:** Angela K. Haskell, Joshua A. Kulas, William E. Carter, June Javens‐Wolfe, Raven Dance Hinkel, Mustapha Moussaif, Jacob S. Smiley, Olivia Lazaro, Sylvia Robertson, Alan D. Palkowitz, Bruce T. Lamb, Timothy I. Richardson, Jeffrey L. Dage, Shaoyou Chu, Travis Johnson, Louis F. Stancato, Abdul Qadir Syed PMC · DOI: 10.1002/alz.71117 · 2026-02-04 ## TL;DR This paper describes a new method to create microglia from human stem cells to study brain immune responses and test treatments for diseases like Alzheimer's. ## Contribution A novel in vitro model of iPSC-derived microglia is developed for studying stimuli-specific neuroimmune responses and therapeutic testing. ## Key findings - iMG rapidly phagocytosed myelin debris and showed changes in lipid homeostasis gene expression. - TREM2 agonist antibody reduced myelin phagocytosis and upregulated CCL1 and CCL22. - IL-4 increased TREM2 and DAP12 expression in iMG but did not enhance myelin uptake. ## Abstract Microglia are macrophage‐like brain resident immune cells known to express numerous Alzheimer's disease risk genes. Here we generated a human induced pluripotent stem cell (iPSC) derived microglia cell culture model for use in neuroimmune modeling and therapeutic testing. We generated iPSC lines using episomal reprogramming for subsequent stepwise differentiation of iPSC‐derived microglia (iMG) without commercial kits. We characterized the responses of this model to immunogenic stimuli and recombinant TREM2 antibodies. The iMG expressed several key microglia signature genes and are morphologically and transcriptionally dynamic. iMG rapidly phagocytosed myelin debris and strongly changed expression of lipid homeostasis genes. iMG expressed TREM2 and increased TREM2 levels in response to IL‐4. Recombinant TREM2 antibody treatment impaired iMG myelin phagocytosis and upregulated chemokines. We validated our iMG model system for the evaluation of biological responses of human microglia‐like cells to stimuli and pharmacological agents for their transcriptional and functional impacts. Human induced pluripotent stem cell (iPSC) lines were generated from blood cells and differentiated into microglia (iPSC‐derived microglia [iMG]) in a stepwise fashion.iMG are morphologically and transcriptionally dynamic in response to diverse immunogenic stimuli.Myelin debris treatment induces dramatic changes in microglial lipid metabolism and induces the formation of lipid droplets.IL‐4 increases the expression of TREM2 and DAP12 in iMG but does not enhance myelin uptake.TREM2 agonist antibody reduces myelin phagocytosis while upregulating CCL1 and CCL22. Human induced pluripotent stem cell (iPSC) lines were generated from blood cells and differentiated into microglia (iPSC‐derived microglia [iMG]) in a stepwise fashion. iMG are morphologically and transcriptionally dynamic in response to diverse immunogenic stimuli. Myelin debris treatment induces dramatic changes in microglial lipid metabolism and induces the formation of lipid droplets. IL‐4 increases the expression of TREM2 and DAP12 in iMG but does not enhance myelin uptake. TREM2 agonist antibody reduces myelin phagocytosis while upregulating CCL1 and CCL22. ## Linked entities - **Genes:** TREM2 (triggering receptor expressed on myeloid cells 2) [NCBI Gene 54209], TYROBP (transmembrane immune signaling adaptor TYROBP) [NCBI Gene 7305], CCL1 (C-C motif chemokine ligand 1) [NCBI Gene 6346], CCL22 (C-C motif chemokine ligand 22) [NCBI Gene 6367] - **Diseases:** Alzheimer's disease (MONDO:0004975) ## Full-text entities - **Genes:** PODXL (podocalyxin like) [NCBI Gene 5420] {aka Gp200, PC, PCLP, PCLP-1, PDX, PODXL1}, PICALM (phosphatidylinositol binding clathrin assembly protein) [NCBI Gene 8301] {aka CALM, CLTH, LAP}, CARD9 (caspase recruitment domain family member 9) [NCBI Gene 64170] {aka CANDF2, IMD103, hCARD9}, SMPDL3A (sphingomyelin phosphodiesterase acid like 3A) [NCBI Gene 10924] {aka ASM3A, ASML3a, yR36GH4.1}, MMP10 (matrix metallopeptidase 10) [NCBI Gene 4319] {aka SL-2, STMY2}, STING1 (stimulator of interferon response cGAMP interactor 1) [NCBI Gene 340061] {aka ERIS, MITA, MPYS, NET23, SAVI, STING}, RPIA (ribose 5-phosphate isomerase A) [NCBI Gene 22934] {aka RPI, RPIAD}, CD34 (CD34 molecule) [NCBI Gene 947], ABCD1 (ATP binding cassette subfamily D member 1) [NCBI Gene 215] {aka ABC42, ALD, ALDP, AMN}, TPO (thyroid peroxidase) [NCBI Gene 7173] {aka MSA, TDH2A, TPX}, BMP4 (bone morphogenetic protein 4) [NCBI Gene 652] {aka BMP2B, BMP2B1, MCOPS6, OFC11, ZYME}, TREM2 (triggering receptor expressed on myeloid cells 2) [NCBI Gene 54209] {aka AD17, PLOSL2, TREM-2, Trem2a, Trem2b, Trem2c}, TGFB1 (transforming growth factor beta 1) [NCBI Gene 7040] {aka CAEND1, CED, DPD1, IBDIMDE, LAP, TGF-beta1}, VIM (vimentin) [NCBI Gene 7431], IRF4 (interferon regulatory factor 4) [NCBI Gene 3662] {aka IMD131, LSIRF, MUM1, NF-EM5, SHEP8}, TMEM119 (transmembrane protein 119) [NCBI Gene 338773] {aka OBIF}, VEGFA (vascular endothelial growth factor A) [NCBI Gene 7422] {aka L-VEGF, MVCD1, VEGF, VPF}, CGAS (cyclic GMP-AMP synthase) [NCBI Gene 115004] {aka C6orf150, D4, MB21D1, h-cGAS}, C1QA (complement C1q A chain) [NCBI Gene 712] {aka C1QD1}, APC (APC regulator of Wnt signaling pathway) [NCBI Gene 324] {aka BTPS2, DESMD, DP2, DP2.5, DP3, GS}, IRF9 (interferon regulatory factor 9) [NCBI Gene 10379] {aka IRF-9, ISGF3, ISGF3G, p48}, IRF8 (interferon regulatory factor 8) [NCBI Gene 3394] {aka H-ICSBP, ICSBP, ICSBP1, IMD32A, IMD32B, IRF-8}, LGI2 (leucine rich repeat LGI family member 2) [NCBI Gene 55203] {aka LGIL2}, IFNG (interferon gamma) [NCBI Gene 3458] {aka IFG, IFI, IMD69}, IL3 (interleukin 3) [NCBI Gene 3562] {aka IL-3, MCGF, MULTI-CSF}, PPARG (peroxisome proliferator activated receptor gamma) [NCBI Gene 5468] {aka CIMT1, FPLD3, GLM1, NR1C3, PPARG1, PPARG2}, SREBF2 (sterol regulatory element binding transcription factor 2) [NCBI Gene 6721] {aka SREBP-2, SREBP2, bHLHd2}, TNC (tenascin C) [NCBI Gene 3371] {aka 150-225, DFNA56, GMEM, GP, HXB, JI}, CCL1 (C-C motif chemokine ligand 1) [NCBI Gene 6346] {aka I-309, P500, SCYA1, SISe, TCA3}, P2RY12 (purinergic receptor P2Y12) [NCBI Gene 64805] {aka ADPG-R, BDPLT8, HORK3, P2T(AC), P2Y(12)R, P2Y(AC)}, LAMP3 (lysosome associated membrane protein 3) [NCBI Gene 27074] {aka CD208, DC LAMP, DC-LAMP, DCLAMP, LAMP, LAMP-3}, BIN1 (bridging integrator 1) [NCBI Gene 274] {aka AMPH2, AMPHL, CNM2, SH3P9}, CCL22 (C-C motif chemokine ligand 22) [NCBI Gene 6367] {aka A-152E5.1, ABCD-1, DC/B-CK, MDC, SCYA22, STCP-1}, IL4 (interleukin 4) [NCBI Gene 3565] {aka BCGF-1, BCGF1, BSF-1, BSF1, IL-4}, Trem2 (triggering receptor expressed on myeloid cells 2) [NCBI Gene 83433] {aka TREM-2, Trem2a, Trem2b, Trem2c}, PLCG2 (phospholipase C gamma 2) [NCBI Gene 5336] {aka APLAID, FCAS3, PLC-IV, PLC-gamma-2}, INPP5D (inositol polyphosphate-5-phosphatase D) [NCBI Gene 3635] {aka SHIP, SHIP-1, SHIP1, SIP-145, hp51CN, p150Ship}, TYROBP (transmembrane immune signaling adaptor TYROBP) [NCBI Gene 7305] {aka DAP12, KARAP, PLOSL, PLOSL1}, Il4 (interleukin 4) [NCBI Gene 16189] {aka BSF-1, Il-4}, RHO (rhodopsin) [NCBI Gene 6010] {aka CSNBAD1, OPN2, RP4}, NR4A3 (nuclear receptor subfamily 4 group A member 3) [NCBI Gene 8013] {aka CHN, CSMF, MINOR, NOR1}, ABCG1 (ATP binding cassette subfamily G member 1) [NCBI Gene 9619] {aka ABC8, WHITE1}, MYCL (MYCL proto-oncogene, bHLH transcription factor) [NCBI Gene 4610] {aka L-Myc, LMYC, MYCL1, bHLHe38}, MSMO1 (methylsterol monooxygenase 1) [NCBI Gene 6307] {aka DESP4, ERG25, MCCPD, SC4MOL}, CD33 (CD33 molecule) [NCBI Gene 945] {aka CD33rSiglec, SIGLEC-3, SIGLEC3, p67}, TP53 (tumor protein p53) [NCBI Gene 7157] {aka BCC7, BMFS5, LFS1, P53, TRP53}, POU5F1 (POU class 5 homeobox 1) [NCBI Gene 5460] {aka OCT3, OCT4, OCT4Borf1, OTF-3, OTF3, OTF4}, SYK (spleen associated tyrosine kinase) [NCBI Gene 6850] {aka IMD82, p72-Syk}, APP (amyloid beta precursor protein) [NCBI Gene 351] {aka AAA, ABETA, ABPP, AD1, APPI, CTFgamma}, PLIN2 (perilipin 2) [NCBI Gene 123] {aka ADFP, ADRP}, ABCA1 (ATP binding cassette subfamily A member 1) [NCBI Gene 19] {aka ABC-1, ABC1, CERP, HDLCQTL13, HDLDT1, HPALP1}, SPN (sialophorin) [NCBI Gene 6693] {aka CD43, GALGP, GPL115, LEU-22, LSN}, CXCL10 (C-X-C motif chemokine ligand 10) [NCBI Gene 3627] {aka C7, IFI10, INP10, IP-10, SCYB10, crg-2}, SPI1 (Spi-1 proto-oncogene) [NCBI Gene 6688] {aka AGM10, OF, PU.1, SFPI1, SPI-1, SPI-A}, SOX17 (SRY-box transcription factor 17) [NCBI Gene 64321] {aka PPH7, VUR3}, HEXB (hexosaminidase subunit beta) [NCBI Gene 3074] {aka ENC-1AS, HEL-248, HEL-S-111}, IL1B (interleukin 1 beta) [NCBI Gene 3553] {aka IL-1, IL1-BETA, IL1F2, IL1beta}, NANOG (Nanog homeobox) [NCBI Gene 79923], CSF1 (colony stimulating factor 1) [NCBI Gene 1435] {aka CSF-1, MCSF, PG-M-CSF}, FGF2 (fibroblast growth factor 2) [NCBI Gene 2247] {aka BFGF, FGF-2, FGFB, HBGF-2} - **Diseases:** HPC (MESH:C537243), Myelin (MESH:D003711), neuroinflammatory insults (MESH:D000090862), RESEARCH (MESH:D014947), iMG (MESH:D000092423), neurological diseases (MESH:D020271), amyloid plaque (MESH:D058225), inflammation (MESH:D007249), neurodegeneration (MESH:D019636), mycoplasma (MESH:D009175), brain injury (MESH:D001930), myelin debris (MESH:C536356), neurotoxicity (MESH:D020258), hypoxic (MESH:D002534), amyloid (MESH:C000718787), iHPCs (MESH:D019337), traumatic brain injury (MESH:D000070642), AD (MESH:D000544) - **Chemicals:** CHIR99021 (MESH:C473711), agarose (MESH:D012685), LDS (MESH:C028913), PVDF (MESH:C024865), magnesium (MESH:D008274), ice (MESH:D007053), citrate (MESH:D019343), rhodamine (MESH:D012235), water (MESH:D014867), LPS (MESH:D008070), SB431542 (MESH:C459179), CytoD (MESH:D015638), Bis-Tris (MESH:C026272), SYBR green (MESH:C098022), DPBS (MESH:C012939), BCA (MESH:C047117), Alexa Fluor 647 (MESH:C569686), cGAMP (MESH:C584311), Y-27632 (MESH:C108830), 4',6-diamidino-2-phenylindole (MESH:C007293), SDS (MESH:D012967), acrylamide (MESH:D020106), EDTA (MESH:D004492), phenol-red (MESH:D010637), ethanol (MESH:D000431), Cholesterol (MESH:D002784), calcium (MESH:D002118), Tween-20 (MESH:D011136), CO2 (MESH:D002245), Alexa Fluor 488 (MESH:C000711379), Lymphoprep (MESH:C038920), paraformaldehyde (MESH:C003043), Lipid (MESH:D008055), Triton X-100 (MESH:D017830), CellMask Green (-) - **Species:** Mus musculus (house mouse, species) [taxon 10090], Staphylococcus aureus (species) [taxon 1280], Homo sapiens (human, species) [taxon 9606] - **Mutations:** L234A, P329G, L235A, G712A - **Cell lines:** Chinese hamster ovary — Cricetulus griseus (Chinese hamster), Spontaneously immortalized cell line (CVCL_0213), hES — Homo sapiens (Human), Embryonic stem cell (CVCL_D092), iMG — Gallus gallus (Chicken), Induced pluripotent stem cell (CVCL_YE48), CHO-S — Cricetulus griseus (Chinese hamster), Spontaneously immortalized cell line (CVCL_7183), E7U7T — Mus musculus (Mouse), Hybridoma (CVCL_C2B0), IBRI 104.B — Rattus norvegicus (Rat), Rat neuroblastoma, Cancer cell line (CVCL_0154) ## Figures 6 figures with captions in the complete paper: https://tomesphere.com/paper/PMC12872402/full.md --- Source: https://tomesphere.com/paper/PMC12872402