{"schema":"https://ver.cy/schemas/card/1.0.0","id":"vr.tr.leukocidin","code":"thing-q16889545","url":"https://ver.cy/models/thing/q16889545/","name":"leukocidin","alternateNames":[],"kind":"thing","status":"research-draft","version":"0.1.0-research.1","language":"en","classifiers":{"family":"Thing Registry","category":"Physical world and living systems","entryKind":"thing","plane":"PHY","domain":["PHY.MAT"],"industry":[],"navPath":"","tags":[],"facets":{}},"whatItIs":"A leukocidin is a bacterial protein exotoxin that damages or kills leukocytes, commonly by forming pores in their cell membranes.","purpose":"Enable an agent to identify a leukocidin, assess its molecular and biological state, and determine whether evidence supports a proposed interpretation or use.","scope":{"in":["Named leukocidins, aliases, sequence identities and component relationships","Protein integrity, preparation composition and demonstrated activity","Host species, leukocyte targets and receptor relationships","Evidence for membrane injury and other measured cellular effects","Attribution limits and preparation-specific handling constraints"],"out":["Whole bacterial organisms, strain classification and culture processes","Toxin genes and their genomic vehicles as independently modelled entities","Host leukocytes and receptors beyond their relationships to the toxin","Infectious diseases, patient diagnosis and treatment decisions","Manufacturing protocols and experimental optimization of toxin activity"],"boundaries":[]},"distinguishingFeatures":["Resolve the name to a toxin category or named member: evidence about Panton-Valentine leukocidin does not identify every leukocidin.","Require protein identity and relevant functional evidence; leukocyte death alone does not establish that an unknown material is a leukocidin.","Distinguish a toxin protein preparation from detection of its encoding genes; gene presence does not establish the preparation's protein content or activity.","For a claimed bicomponent leukocidin, identify both components and distinguish individual subunits from the assembled toxin. [Primary structural study](https://pubmed.ncbi.nlm.nih.gov/11910032/).","Use member-specific receptor evidence to distinguish related toxins: LukAB targets CD11b, whereas PVL and HlgCB interact with human C5a receptors. [LukAB study](https://pmc.ncbi.nlm.nih.gov/articles/PMC3696772/), [PVL and HlgCB study](https://pmc.ncbi.nlm.nih.gov/articles/PMC4506853/)."],"structure":{"bundles":[{"id":"leukocidin-identity","name":"Leukocidin identity","description":"Resolve what the leukocidin name denotes and how narrowly its properties can be assigned.","layers":[{"id":"name-and-boundary","name":"Name and boundary","description":"Separate registry scope from narrower toxin names and broader descriptions of leukocyte toxicity.","findings":[{"id":"named-member-resolution","name":"Named member resolution","description":"Record the intended member or retain an explicit unresolved identity.","questions":[{"text":"Does leukocidin denote the general category, a named toxin such as PVL, or an isolated protein component here?","id":"named-member-resolution-q01","kind":"definition"},{"text":"Which source establishes the supplied name or alias for this material?","id":"named-member-resolution-q02","kind":"provenance"}]}]},{"id":"molecular-attribution","name":"Molecular attribution","description":"Connect toxin identity to protein evidence and its biological source.","findings":[{"id":"protein-versus-gene-evidence","name":"Protein versus gene evidence","description":"Keep protein identification distinct from evidence that an organism carries a corresponding gene.","questions":[{"text":"Which protein accessions or sequence observations support this leukocidin assignment?","id":"protein-versus-gene-evidence-q01","kind":"provenance"},{"text":"Does the evidence establish toxin protein, encoding genes, or only a leukocytotoxic phenotype?","id":"protein-versus-gene-evidence-q02","kind":"boundary"}]}]}]},{"id":"components-and-integrity","name":"Components and integrity","description":"Describe the molecular constituents and physical state of the toxin being represented.","layers":[{"id":"component-architecture","name":"Component architecture","description":"Record the architecture supported for the identified leukocidin.","findings":[{"id":"bicomponent-identity","name":"Bicomponent identity","description":"For applicable staphylococcal leukocidins, distinguish the two protein classes and the assembled pore. [Primary structural study](https://pubmed.ncbi.nlm.nih.gov/11910032/).","questions":[{"text":"What component architecture is established for this named toxin?","id":"bicomponent-identity-q01","kind":"definition"},{"text":"Which required components are identified in the represented preparation?","id":"bicomponent-identity-q02","kind":"measurement"}]}]},{"id":"preparation-state","name":"Preparation state","description":"Assess whether measured protein content corresponds to the intended molecular material.","findings":[{"id":"integrity-and-composition","name":"Integrity and composition","description":"Record component amounts, integrity and contamination without treating nominal purity as proof of activity.","questions":[{"text":"What concentrations and purity measurements are available for the individual toxin components?","id":"integrity-and-composition-q01","kind":"measurement"},{"text":"What evidence identifies fragmentation, aggregation or other material that could affect interpretation?","id":"integrity-and-composition-q02","kind":"measurement"}]}]}]},{"id":"host-and-cell-recognition","name":"Host and cell recognition","description":"Attach toxin activity to a defined host, leukocyte population and receptor context.","layers":[{"id":"receptor-relations","name":"Receptor relations","description":"Record receptor relationships at the named-toxin level.","findings":[{"id":"member-specific-receptor-evidence","name":"Member-specific receptor evidence","description":"LukAB recognition of CD11b illustrates why receptor assignments require toxin-specific evidence. [Primary study](https://pmc.ncbi.nlm.nih.gov/articles/PMC3696772/).","questions":[{"text":"Which receptor interaction is demonstrated for this toxin and host species?","id":"member-specific-receptor-evidence-q01","kind":"provenance"},{"text":"Does the evidence establish binding, functional dependence or merely association?","id":"member-specific-receptor-evidence-q02","kind":"boundary"}]}]},{"id":"species-and-cell-context","name":"Species and cell context","description":"Preserve the biological limits of observed susceptibility.","findings":[{"id":"susceptibility-boundaries","name":"Susceptibility boundaries","description":"PVL and HlgCB receptor studies demonstrate that related toxins can differ in their response to receptor variation. [Primary study](https://pmc.ncbi.nlm.nih.gov/articles/PMC4506853/).","questions":[{"text":"Which host species and leukocyte populations were actually examined?","id":"susceptibility-boundaries-q01","kind":"measurement"},{"text":"What evidence supports extending the observation to a different species, cell population or activation state?","id":"susceptibility-boundaries-q02","kind":"boundary"}]}]}]},{"id":"activity-and-attribution","name":"Activity and attribution","description":"Represent observed effects while distinguishing molecular mechanism, cellular injury and disease relevance.","layers":[{"id":"cellular-endpoints","name":"Cellular endpoints","description":"Keep binding, membrane permeabilization, lysis and other responses separately interpretable.","findings":[{"id":"endpoint-specific-activity","name":"Endpoint-specific activity","description":"Attach every activity observation to its endpoint, preparation and biological context.","questions":[{"text":"Was the measured endpoint receptor binding, pore formation, membrane injury, cell death or another response?","id":"endpoint-specific-activity-q01","kind":"measurement"},{"text":"Are component amounts, observation duration, cell context and uncertainty reported well enough to interpret the result?","id":"endpoint-specific-activity-q02","kind":"measurement"}]}]},{"id":"causal-interpretation","name":"Causal interpretation","description":"Assess how specifically an observation can be attributed to the identified leukocidin.","findings":[{"id":"toxin-specific-causation","name":"Toxin-specific causation","description":"Distinguish effects of an identified toxin preparation from effects of a bacterial mixture or clinical association.","questions":[{"text":"What evidence separates this leukocidin's contribution from other constituents or virulence factors?","id":"toxin-specific-causation-q01","kind":"provenance"},{"text":"Does the available evidence support a cellular effect, a contribution to infection, or only an association?","id":"toxin-specific-causation-q02","kind":"boundary"}]}]}]},{"id":"preparation-fitness-and-handling","name":"Preparation fitness and handling","description":"Connect the preparation's documented condition to permitted interpretation and use.","layers":[{"id":"condition-and-reliability","name":"Condition and reliability","description":"Determine whether preparation history undermines existing characterization.","findings":[{"id":"current-characterization","name":"Current characterization","description":"Record formulation and handling history alongside the date and scope of integrity or activity evidence.","questions":[{"text":"What formulation and storage history accompany this leukocidin preparation?","id":"current-characterization-q01","kind":"provenance"},{"text":"What evidence shows that its present integrity and activity remain consistent with its characterization?","id":"current-characterization-q02","kind":"measurement"}]}]},{"id":"use-determination","name":"Use determination","description":"Link preparation-specific documentation to decisions about handling and use.","findings":[{"id":"documented-use-constraints","name":"Documented use constraints","description":"Record applicable institutional assessments and supplier documentation without inventing a universal classification for all leukocidins.","questions":[{"text":"Which documented handling requirements and use restrictions apply to this exact preparation?","id":"documented-use-constraints-q01","kind":"provenance"},{"text":"Do unresolved identity, activity or documentation gaps require withholding the proposed use pending assessment?","id":"documented-use-constraints-q02","kind":"action"}]}]}]},{"id":"evidence-and-external-alignment","name":"Evidence and external alignment","description":"What the world already says about this thing, gathered so the model can be checked against it.","layers":[{"id":"reported-evidence","name":"Reported evidence","description":"Findings from the breadth pass, kept separate from the structural claims.","findings":[{"id":"evidence-confidence-notes","name":"Check these first","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these check these first hold for the sense of leukocidin this model covers, and on what evidence?","id":"evidence-confidence-notes-q01","kind":"provenance"}]},{"id":"evidence-kinds","name":"Kinds and varieties","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these kinds and varieties hold for the sense of leukocidin this model covers, and on what evidence?","id":"evidence-kinds-q01","kind":"provenance"}]},{"id":"evidence-identifiers","name":"Identifiers and schemes","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these identifiers and schemes hold for the sense of leukocidin this model covers, and on what evidence?","id":"evidence-identifiers-q01","kind":"provenance"}]},{"id":"evidence-real-world-use","name":"Real-world use","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these real-world use hold for the sense of leukocidin this model covers, and on what evidence?","id":"evidence-real-world-use-q01","kind":"provenance"}]},{"id":"evidence-measurements","name":"Typical measurements","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these typical measurements hold for the sense of leukocidin this model covers, and on what evidence?","id":"evidence-measurements-q01","kind":"provenance"}]},{"id":"evidence-failure-modes-and-hazards","name":"Failure modes and hazards","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these failure modes and hazards hold for the sense of leukocidin this model covers, and on what evidence?","id":"evidence-failure-modes-and-hazards-q01","kind":"provenance"}]},{"id":"evidence-neighbours","name":"Neighbouring kinds and how to tell them apart","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these neighbouring kinds and how to tell them apart hold for the sense of leukocidin this model covers, and on what evidence?","id":"evidence-neighbours-q01","kind":"provenance"}]}]}]}]},"agentConduct":{"may":["Resolve a leukocidin label to a named toxin, component or explicitly unresolved category.","Check whether a preparation contains the components its identity claim requires.","Compare published activity observations only across adequately matched biological contexts.","Identify missing evidence before attributing cell injury to a particular leukocidin.","Flag preparations whose identity, integrity or handling determination is insufficient for the proposed use."],"mustNot":["Leukocidin identity cannot be established from visual appearance because these proteins lack distinctive visible features."],"requiresHuman":["Use member-specific receptor evidence to distinguish related toxins: LukAB targets CD11b, whereas PVL and HlgCB interact with human C5a receptors. [LukAB study](https://pmc.ncbi.nlm.nih.gov/articles/PMC3696772/), [PVL and HlgCB study](https://pmc.ncbi.nlm.nih.gov/articles/PMC4506853/)."]},"ethics":{"considerations":[],"affectedParties":[]},"owners":{"steward":"","roles":[],"masterSystems":[]},"relations":[{"target":"Q7230047","type":"parent","note":"registry parent class"}],"interaction":{"identity":{"applicability":"required","items":["Vercy registry: vr.tr.leukocidin","Wikidata: Q16889545 (https://www.wikidata.org/wiki/Q16889545)"]},"properties":{"applicability":"required","items":["Leukocidin identity: Named member, documented alias, unresolved leukocidin or disputed assignment","Component identity: Protein accessions, sequence versions and documented component pairing","Molecular mass: kDa, with component or assembly specified and calculated versus measured status","Component concentration: nmol/L or µg/mL for each identified component","Purity and co-occurring material: Percentage by stated method, with identified contaminants and detection limits","Protein integrity and assembly: Intact, fragmented, aggregated, unassembled, assembled or uncharacterized, with evidence","Target context: Host species, cell type, receptor identity and receptor evidence","Observed cellular effect: Percentage permeabilization, lysis or viability change, with endpoint, duration and uncertainty","Preparation history: Formulation, recorded storage history, integrity assessment and activity verification date","Handling determination: Documented permitted use, restricted use, pending assessment or disposal designation"]},"recognition":{"applicability":"not-applicable","items":[]},"capabilities":{"applicability":"required","items":["Resolve a leukocidin label to a named toxin, component or explicitly unresolved category.","Check whether a preparation contains the components its identity claim requires.","Compare published activity observations only across adequately matched biological contexts.","Identify missing evidence before attributing cell injury to a particular leukocidin.","Flag preparations whose identity, integrity or handling determination is insufficient for the proposed use."]},"hazards":{"applicability":"required","items":["Exposure to biologically active leukocidin can damage susceptible immune cells.","Misidentified or contaminated preparations can produce misleading experimental results and incorrect conclusions about bacterial virulence.","Unrecognised differences in toxin activity or target species can undermine exposure assessments and experimental interpretation."]},"interfaces":{"applicability":"required","items":["The Occupational Exposure to Hazardous Chemicals in Laboratories standard, issued by the United States Occupational Safety and Health Administration as 29 CFR 1910.1450, applies to laboratory use of leukocidin preparations that meet its hazardous chemical criteria."]},"context":{"applicability":"required","items":["Leukocidins are studied in microbiology, infectious disease research and investigations of bacterial virulence.","Their identification and activity help researchers interpret interactions between bacterial pathogens and immune cells."]}},"sources":[{"title":"Wikidata item Q16889545: leukocidin","url":"https://www.wikidata.org/wiki/Q16889545","note":"identity and sense of the item"},{"title":"Wikipedia: Leukocidin","url":"https://en.wikipedia.org/wiki/Leukocidin","note":"general description of the item"}],"openQuestions":["Does the registry intend leukocidin broadly as a leukocyte-damaging bacterial toxin category or specifically as the staphylococcal bicomponent family?","Which named members, historical aliases and overlapping hemolysin labels belong under this entry without creating duplicate concepts?","Which sequence variants and preparations have directly established receptor and host-cell relationships, and which assignments remain inferred?","Which available activity measurements are sufficiently comparable to support cross-study conclusions?","Which preparation-specific identity records, stability evidence and handling determinations can be verified from authoritative documentation?"],"resources":{"spec":"/models/things/publications/thing-q16889545/spec.json"},"provenance":{"origin":"thing registry research (pass 2)","builtFrom":["models/things/publications/thing-q16889545/spec.json"],"providers":["Codex"],"researchStatus":"unreviewed","generatedAt":"2026-09-12T10:57:00Z","builder":"tools/build_cards.py@1.0.0"},"completeness":{"sections":{"classifiers":"filled","whatItIs":"filled","purpose":"filled","distinguishingFeatures":"filled","structure":"filled","agentConduct":"derived","ethics":"missing","owners":"missing","relations":"filled","interaction.identity":"filled","interaction.properties":"filled","interaction.recognition":"not-applicable","interaction.capabilities":"filled","interaction.hazards":"filled","interaction.interfaces":"filled","interaction.context":"filled","sources":"filled"},"notes":{"agentConduct":"Affordances listed as what may be done; prohibitions collected from the text.","interaction.recognition":"Leukocidin identity cannot be established from visual appearance because these proteins lack distinctive visible features."},"score":0.844}}