Generation of human iPSC-derived macrophages under animal-free conditions enables their application for safety and efficacy testing

ABSTRACT: Generation and use of human macrophages in vitro are essential for a variety of (therapeutic) applications. Recently, there has been growing interest in macrophages derived from induced pluripotent stem cells (iPSC-Mac), which has led to the development of numerous differentiation protocols. These protocols typically involve a stepwise differentiation process using well-defined culture media, though the final differentiation stage often relies on undefined animal serum components, such as fetal bovine serum (FBS). In this study, we assessed the impact of a serum-containing medium in comparison to a fully defined medium (X-VIVO 15TM) on human iPSC-Mac function. While both media compositions effectively produced fully functional human macrophages, we observed significant differences in their stage of activation and their functional responsiveness. Macrophages differentiated under the defined, serum-free conditions showed a more neutral activation state, an enhanced cholesterol metabolism, and were more sensitive to post pro- or anti-inflammatory stimulation compared to serum-grown cells. Most important, iPSC-Mac from these cultures also exhibit a more robust and reproducible response to co-stimulatory signals with IFNγ or lipopolysaccharide (LPS) in combination with the immune-suppressive agent dexamethasone. In contrast, serum-grown iPSC-Mac demonstrated a more pre-activated state, with noteworthy background levels of interleukin 6 (IL-6). Upon stimulation, these cells showed reduced sensitivity and responsiveness towards secondary signals, underscoring potential challenges when using FBS-based media for drug screening or immunomodulatory assessments. Given the enhanced responsiveness to co-stimulatory signals makes iPSC-Mac from defined-cultures more suitable for testing immunomodulatory drugs, novel bio-assays and in vivo applications.

INSTRUMENT(S):

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Monocyte

SUBMITTER: Lothar Jaensch  

LAB HEAD: Lothar Jänsch

PROVIDER: PXD070961 | Pride | 2026-04-27

REPOSITORIES: Pride