Host-Microsporidia Interactions in Caenorhabditis elegans , a Model Nematode Host

Abstract

Microsporidia comprise a phylum of obligate intracellular pathogens related to fungi that infect virtually all animals. Recently, the nematode Caenorhabditis elegans has been developed as a convenient model for studying microsporidia infection in a whole-animal host through the identification and characterization of a natural microsporidian pathogen of this commonly studied laboratory organism. The C. elegans natural microsporidian pathogen is named Nematocida parisii, and it causes a lethal intestinal infection in C. elegans. Comparison of the genomes of N. parisii and its closely related species Nematocida sp. 1, together with the genomes of other microsporidian species, has provided insight into the evolutionary events that led to the emergence of the large, specialized microsporidia phylum. Cell biology studies of N. parisii infection in C. elegans have shown how N. parisii restructures host intestinal cells and, in particular, how it hijacks host exocytosis for nonlytic exit to facilitate transmission. Recent results also show how the host responds to infection with ubiquitin-mediated responses, and how a natural variant of C. elegans is able to clear N. parisii infection, but only during early life. Altogether, these studies provide insight into the mechanisms of microsporidia pathogenesis using a whole-animal host.

A Microsporidian Infection in Phoronids (Phylum Phoronida): Microsporidium phoronidi n. sp. from a Phoronis embryolabi

“…Nuclei and other organelles could be hardly distinguished in their homogenous cytoplasm. We speculate that while merogonial plasmodia proliferate and grow, they restructure vasoperitoneal epithelium layer and transform it in a syncytium in a way described recently for Nematocida parissi infecting intestine of Caenorhabditis elegans (Troemel 2016). Sporonts, sporoblasts, and spores were often seen on sections submerged into an amorphous substance of moderate electron density surrounded by a membrane (Fig.…”

YAP in epithelium senses gut barrier loss to deploy defenses against pathogens

“…The model organism Caenorhabditis elegans is capable of detecting infection and protecting itself from diverse pathogens [33][34][35]. In this report, we took advantage of the simple intestine of C. elegans to elucidate the role of the intestinal epithelium in host defense against bacterial infection when the epithelial barrier is disrupted.…”

“…The model organism Caenorhabditis elegans is capable of detecting infection and protecting itself from diverse pathogens [ 33 – 35 ]. In this report, we took advantage of the simple intestine of C .…”

Nuclear hormone receptors promote gut and glia detoxifying enzyme induction and protect C. elegans from the mold P. brevicompactum

“…A number of experimental paradigms have been established to study the interactions between C. elegans and model microbial pathogens ( Jiang and Wang, 2018 ; Kim and Ewbank, 2018 ; Kim and Flavell, 2020 ; Madende et al, 2020 ; Radeke and Herman, 2021 ; Troemel, 2016 ). Recent work has also explored the interactions between C. elegans and the microbial components of its natural substrates in the wild ( Schulenburg and Félix, 2017 ; Zhang et al, 2017 ), with most of these studies focusing on bacteria.…”