Toxic Avengers
Host-parasite interactions shape the evolution of the immune system as well as the strategies used to subvert it. However, it is now clear that animals also partner with microbial symbionts to help fend off parasites, and we are interested in the mechanisms and processes that underlie this symbiont-mediated protection. In our lab, we study a maternally-transmitted, cell wall-less bacterium called Spiroplasma that defends its insect hosts against endoparasites, organisms that develop inside the body of the host. Spiroplasma protects fruit flies in the genus Drosophila against infection by parasitic nematodes and wasps. The symbiont produces toxins, ribosome-inactivating proteins (RIPs), that permanently inactivate parasites' protein translation machinery. Understanding how RIPs distinguish between host and parasite cells is a major goal of our research. We are also interested in studying the generality of RIPs as defensive effectors against the numerous other parasites that infect insects.
Host-parasite interactions shape the evolution of the immune system as well as the strategies used to subvert it. However, it is now clear that animals also partner with microbial symbionts to help fend off parasites, and we are interested in the mechanisms and processes that underlie this symbiont-mediated protection. In our lab, we study a maternally-transmitted, cell wall-less bacterium called Spiroplasma that defends its insect hosts against endoparasites, organisms that develop inside the body of the host. Spiroplasma protects fruit flies in the genus Drosophila against infection by parasitic nematodes and wasps. The symbiont produces toxins, ribosome-inactivating proteins (RIPs), that permanently inactivate parasites' protein translation machinery. Understanding how RIPs distinguish between host and parasite cells is a major goal of our research. We are also interested in studying the generality of RIPs as defensive effectors against the numerous other parasites that infect insects.
Generality of toxins in defensive symbiosis
PLoS Pathogens
Featured on the podcast This Week in Microbiology
Paleovirology
Retroviruses are RNA viruses that reverse-transcribe their genomes into DNA and integrate into the host genome. It's not surprising that in the modern age we find lots of fossilized retroviruses preserved in animal genomes; these "paleoviruses" tell the stories of ancient viral infections. Amongst the waves of recent discoveries brought on by the age of genomics was the unexpected identification of genes derived from nonretroviral RNA viruses (those that have no DNA or integration stage in the replication cycle) also preserved in animal genomes. These genes are converted to DNA by host-encoded reverse-transcriptases and integrated. Some are dead-on-arrival, while others appear to be functional as transcribed RNAs or proteins. We are interested in how these genetic elements are co-opted by the host and how they interact with their cognate viruses and the innate immune system during infection.