ReviewInsights from the worm: The C. elegans model for innate immunity

- C. elegans as ancestral metazoan system for studying innate immunity.
- The RNAi machinery is important for anti-viral defense.
- Pathogen response to bacterial infections are mediated by MAPK signaling.
- Innate immunity is linked to stress responses and longevity regulation.
- Germline DNA damage induces systemic stress resistance (GDISR) through innate immune signaling.

The nematode worm Caenorhabditis elegans comprises an ancestral immune system. C. elegans recognizes and responds to viral, bacterial, and fungal infections. Components of the RNA interference machinery respond to viral infection, while highly conserved MAPK signaling pathways activate the innate immune response to bacterial infection. C. elegans has been particularly important for exploring the role of innate immunity in organismal stress resistance and the regulation of longevity. Also functions of neuronal sensing of infectious bacteria have recently been uncovered. Studies on nematode immunity can be instructive in exploring innate immune signaling in the absence of specialized immune cells and adaptive immunity.