{"doi":"10.1101/2021.01.22.427304","title":"Direct imaging of anthrax intoxication in animals reveals shared and individual functions of CMG-2 and TEM-8 in cellular toxin entry","abstract":"SUMMARY The virulence of Bacillus anthracis is linked to the secretion of anthrax lethal toxin and anthrax edema toxin. These binary toxins consist of a common cell-binding moiety, protective antigen (PA), and the enzymatic moieties, lethal factor (LF) and edema factor (EF). PA binds either of two specific cell surface receptors, capillary morphogenesis protein-2 (CMG-2) or tumor endothelial marker-8 (TEM-8), which triggers the binding, endocytosis, and cytoplasmic translocation of LF and EF. The cellular distribution of functional TEM-8 and CMG-2 receptors during anthrax toxin intoxication in animals is not fully elucidated. Herein, we describe a novel assay to image anthrax toxin intoxication in live animals, and we use the assay to visualize TEM-8- and CMG-2-dependent intoxication. Specifically, we generated a chimeric protein consisting of the N-terminal domain of LF fused to a nuclear localization signal-tagged Cre recombinase (LFn-NLS-Cre). When PA and LFn-NLS-Cre were co-administered to transgenic mice that ubiquitously express a red fluorescent protein in the absence of Cre activity and a green fluorescent protein in the presence of Cre activity, anthrax toxin intoxication could be visualized at single-cell resolution by confocal microscopy. By using this assay, we show that CMG-2 is critical for intoxication in the liver and heart, whereas TEM-8 is required for full intoxication in the kidney and spleen. Other tissues examined were largely unaffected by single deficiences in either receptor, suggesting extensive overlap in TEM-8 and CMG-2 expression. The novel assay will be useful for basic and clinical/translational studies of Bacillus anthracis infection and for identifying on- and off-targets for reengineered toxin variants in the clinical development of cancer treatments. Background Assays for imaging of anthrax toxin intoxication in animals are not available. Results Anthrax toxin-Cre fusions combined with fluorescent Cre reporter mice enabled imaging of anthrax toxin intoxication in animals. Conclusion Shared and distinct functions of toxin receptors in cellular entry were uncovered. Significance. A simple and versatile assay for anthrax toxin intoxication is described.","journal":"bioRxiv (Cold Spring Harbor Laboratory)","year":2021,"id":220118,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":1,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9593,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2021-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":624251,"name":"Elizabeth M. Chun","orcid":"0000-0001-7916-9308","position":1,"is_corresponding":false},{"id":377628,"name":"Rasem Fattah","orcid":null,"position":2,"is_corresponding":false},{"id":376301,"name":"Mahtab Moayeri","orcid":"0000-0002-4448-8883","position":3,"is_corresponding":false},{"id":794094,"name":"Dennis Paliga","orcid":"0000-0002-0447-6212","position":4,"is_corresponding":false},{"id":794095,"name":"Sebastian Neumann","orcid":"0000-0003-3706-9012","position":5,"is_corresponding":false},{"id":794096,"name":"Rolf Heumann","orcid":"0000-0003-4364-2655","position":6,"is_corresponding":false},{"id":285706,"name":"Stephen H. Leppla","orcid":"0000-0001-5233-0501","position":7,"is_corresponding":false},{"id":371359,"name":"Thomas Bugge","orcid":"0000-0001-7046-4060","position":8,"is_corresponding":false},{"id":794093,"name":"Carly Merritt","orcid":"0000-0001-9233-6940","position":0,"is_corresponding":true}],"reference_count":59,"raw_metadata":null,"created_at":"2026-07-18T23:53:42.928212Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}