Studying Inherited Immunity in a Caenorhabditis elegans Model of Microsporidia Infection

Inherited immunity describes how some animals can pass on the memory of a previous infection to their offspring. This can boost pathogen resistance in their progeny and promote survival. While inherited immunity has been reported in many invertebrates, the mechanisms underlying this epigenetic phenomenon are largely unknown. The infection of Caenorhabditis elegans by the natural microsporidian pathogen Nematocida parisii results in the worms producing offspring that are robustly resistant to microsporidia. The present protocol describes the study of intergenerational immunity in the simple and genetically tractable N. parisii -C. elegans infection model. The current article describes methods for infecting C. elegans and generating immune-primed offspring. Methods are also given for assaying resistance to microsporidia infection by staining for microsporidia and visualizing infection by microscopy. In particular, inherited immunity prevents host cell invasion by microsporidia, and fluorescence in situ hybridization (FISH) can be used to quantify invasion events. The relative amount of microsporidia spores produced in the immuneprimed offspring can be quantified by staining the spores with a chitin-binding dye. To date, these methods have shed light on the kinetics and pathogen specificity of inherited immunity, as well as the molecular mechanisms underlying it. These techniques, alongside the extensive tools available for C. elegans research, will enable important discoveries in the field of inherited immunity.

Automated summary

Inherited immunity is the phenomenon where animals can pass on the memory of a previous infection to their offspring, boosting pathogen resistance. However, the mechanisms behind this phenomenon are still largely unknown. This study presents a protocol for studying inherited immunity in the Nematocida parisii-Caenorhabditis elegans infection model, providing methods for infection, generating immune-primed offspring, and assaying resistance to microsporidia infection.