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SUMMARY Bacterial and host cyclic dinucleotides (cdNs) mediate cytosolic immune responses through the STING signaling pathway, though evidence suggests alternative pathways exist. We used cdN-conjugated beads to biochemically isolate host receptors for bacterial cdNs, and identified the oxidoreductase RECON. High-affinity cdN binding inhibited RECON enzyme activity by simultaneously blocking the substrate and co-substrate sites, as revealed by structural analyses. During bacterial infection of macrophages, RECON antagonized STING activation by acting as a molecular sink for cdNs. Bacterial infection of hepatocytes, which do not express STING, revealed that RECON negatively regulates NF-κB activation. Loss of RECON activity, via genetic ablation or inhibition by cdNs, resulted in increased NF-κB activation and reduced bacterial survival, suggesting that cdN inhibition of RECON promotes a proinflammatory, antibacterial state that is distinct from the anti-viral state associated with STING activation. Thus, RECON functions as a cytosolic pattern recognition receptor specific for bacterial cdNs, shaping inflammatory gene activation via its effects on STING and NF-κB.

Wikidata is a community-maintained knowledge base that has been assembled from repositories in the fields of genomics, proteomics, genetic variants, pathways, chemical compounds, and diseases, and that adheres to the FAIR principles of findability, accessibility, interoperability and reusability. Here we describe the breadth and depth of the biomedical knowledge contained within Wikidata, and discuss the open-source tools we have built to add information to Wikidata and to synchronize it with source databases. We also demonstrate several use cases for Wikidata, including the crowdsourced curation of biomedical ontologies, phenotype-based diagnosis of disease, and drug repurposing.

The exit of intracellular pathogens from host cells is an important step in the infectious cycle, but is poorly understood. It has recently emerged that microbial exit is a process that can be directed by organisms from within the cell, and is not simply a consequence of the physical or metabolic burden that is imposed on the host cell. This Review summarizes our current knowledge on the diverse mechanisms that are used by intracellular pathogens to exit cells. An integrated understanding of the diversity that exists for microbial exit pathways represents a new horizon in the study of host-pathogen interactions.