AUTHOR=Etna Marilena Paola , Fuoco Claudia , Severa Martina , Ricci Daniela , Sinigaglia Alessandro , Lucca Camilla , Cairo Giada , Bottazzi Barbara , Garlanda Cecilia , Palamara Anna Teresa , Barzon Luisa , Gargioli Cesare , Coccia Eliana Marina TITLE=A biomimetic model composed of injectable 3D muscle-like tissue, stromal and immune cells for recapitulating the rapid immune signature predictive of mRNA vaccine immunogenicity JOURNAL=Frontiers in Immunology VOLUME=Volume 16 - 2025 YEAR=2025 URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2025.1651095 DOI=10.3389/fimmu.2025.1651095 ISSN=1664-3224 ABSTRACT=BackgroundSystem vaccinology identified an early innate signature associated with vaccine-mediated protection whose induction is likely to involve both immune and non-immune cells.MethodsTo dissect muscle and stromal cell contribution, we simulated in vitro anti-COVID19 BNT162b2 mRNA vaccine intramuscular administration in human primary cell systems composed of 3D muscle-like tissue (3D-MT), fibroblasts, and peripheral blood mononuclear cells (PBMC).ResultsBNT162b2 vaccine was recognized by all cell types, although fibroblasts only translated the spike antigen. Factors from vaccine-injected 3D-MT stimulated monocyte and macrophage recruitment and promoted inflammatory macrophage activation, while stromal factors improved dendritic cell frequency and activation. Conditioned media from vaccine-exposed 3D-MT and fibroblasts elicited in PBMC the expression of an early innate immune module previously associated with protective responses in BNT162b2 vaccinees.ConclusionThus, models combining human PBMC, stromal and muscle cells could be employed for the in vitro validation of system vaccinology findings and non-animal vaccine pre-clinical testing.