Cellular Responses to Infections in Caenorhabditis elegans

The nematode Caenorhabditis elegans has emerged as a powerful model system to study cellular responses to microbial infections in the context of a whole animal. Like other free-living nematodes, the one millimeter long nematode C. elegans lives in the soil, where it is in contact with soil-borne microbes, including human microbial pathogens. While it lacks adaptive immunity, it has evolved mechanisms to recognize different pathogens and to respond accordingly. Caenorhabditis elegans does not seem to have conserved pattern recognition receptors (PRRs) for pathogen detection through microbe-associated molecular patterns (MAMPs), but it can recognize pathogen attack through different mechanisms, including neuronal sensation of bacterial cues and detection of disturbances of cellular homeostasis. The immune response mounted by Caenorhabditis elegans upon pathogen infection comprises evolutionarily conserved signaling pathways that result in the induction of immune effector mechanisms to combat infections. The immune response is complex and pathogen-specific.