Explosive cytotoxicity of ruptoblasts bridges hormone surveillance and immune defense - PubMed
4 hours ago
- #ruptoblasts
- #cytotoxicity
- #immune evolution
- Identifies 'ruptoblasts', a previously unknown cytotoxic glandular cell type in planarian flatworms.
- Ruptoblasts undergo explosive cell death 'ruptosis', triggered by the hormone/cytokine activin.
- Ruptosis releases diffusible cytotoxic agents that eliminate nearby cells, bacteria, and mammalian cells quickly.
- Excessive activin from injection, chimerism, or infection initiates ruptosis, linking hormone surveillance to immune defense.
- Ablation of ruptoblasts suppresses inflammation but impairs bacterial clearance, showing their immune role.
- Mechanistically distinct, ruptosis relies on ER-derived calcium and cytoskeleton-dependent signal amplification.
- Ruptoblast-like cells are conserved in basal bilaterians, suggesting an ancient evolutionary origin.