Human iPSC-Based Alveolus-on-Chip Reveals Immunometabolic Regulation of Influenza A Virus Infection by Butyrate

Introduction Human-induced pluripotent stem cell (hiPSC)-derived organ-on-chip models enable the creation of patient-specific lung models. Here, we introduce a novel model that mimics the human alveolus by combining autologous iPSC-derived alveolar type II (AT2) cells, iPSC-derived endothelial cells, and macrophages within a system that simulates the lung microenvironment. Using this integrated system, we examined how butyrate, a gut bacterial-derived metabolite, affects the respiratory response to the influenza A virus. Results Following IAV infection, single-cell RNA sequencing revealed a macrophage subset closely resembling human alveolar macrophages, with distinct macrophage subclusters marked by CD68, MARCO, MRC1, and ITGAX, reflecting alveolar macrophage heterogeneity. Butyrate treatment showed a dual immunometabolic effect, suppressing biosynthetic pathways while enhancing antiviral interferon signalling, while at the same time, interferon-stimulated genes (ISG15, OAS family, S100A6) and antiviral pathways were found upregulated, supporting a balanced immune response. Butyrate-treated samples exhibited reduced viral replication and decreased expression of pro-inflammatory cytokines compared to control samples. Conclusion Our findings demonstrate that butyrate can fine-tune antiviral immunity in a human hiPSC-derived alveolar organ-on-chip model by limiting viral replication while preventing excessive inflammation. This highlights a mechanistic link between gut microbiota-derived metabolites and lung antiviral defense, underscoring the potential of autologous stem-cell based microphysiological systems for studying host–microbiome–virus interactions and preclinical testing of immunomodulatory interventions. Acknowledgments This work was supported by the Leibniz ScienceCampus InfectoOptics Jena, which is financed by the funding line Strategic Networking of the Leibniz Association. References [1] Koceva, H. and A. Mosig, Human-Induced Pluripotent Stem Cell-Based Alveolus-on-Chip Model to Study Influenza Virus A Infection. Methods Mol Biol, 2025. 2890: p. 225-235. [2] Koceva et al., J. Vis. Exp., 2024. [3] Koceva et al., Open Biol., 2025.

PhD start: 07/01/2020