identifier: traitmech:000633
label: trogocytosis
definition: A physiological phenotype in which a microbial organism removes and takes
  up discrete portions of another living cell during direct contact instead of engulfing
  that cell whole.
definition_source: DOI:10.1038/nature13242
trait_category: PHYSIOLOGY
term_kind: CLASS
mapping_status: PROPOSED
parent_traits:
- METPO:1000059
evidence:
- reference: DOI:10.1038/nature13242
  snippet: amoebae kill by ingesting distinct pieces of living human cells
  notes: PMID:24717428, PMC4006097. Direct scientific Abstract quote from the final
    Nature/PubMed version, not the differently worded PMC author-manuscript Summary.
    Author-manuscript Results and Discussion, relevant imaging and cell-culture Methods,
    and actual Figures 1-2 were inspected at https://pmc.ncbi.nlm.nih.gov/articles/PMC4006097/.
    Uptake precedes target-cell death; attachment alone is not uptake. Internalization
    and fragmentation gates are distinct measurements. Other figures and movies were
    not visually audited. No universal killing threshold, nutritional benefit or complete
    protein mechanism is inferred.
- reference: DOI:10.1128/mBio.00068-19
  snippet: Protection from human serum occurs only after amoebae have undergone trogocytosis
    of live cells but not phagocytosis of dead cells.
  notes: PMID:31040235, PMC6495370. Direct scientific Abstract quote, not the separate
    Importance/precis block. Cell-culture Methods, membrane-display and live/dead-cell
    Results, Discussion, and actual Figures 1, 6 and 8 were inspected at https://pmc.ncbi.nlm.nih.gov/articles/PMC6495370/.
    Figure 6B measures the percentage of internalizing amoebae, not material mass
    per cell. Figure 8 is a proposed model, not direct proof of a membrane-fusion
    or trafficking route. Other figures and supplements were not visually audited.
    Serum protection is condition-specific, not definitional.
canonical_examples:
- taxon_id: NCBITaxon:5759
  taxon_label: Entamoeba histolytica
  reference: DOI:10.1128/mBio.00068-19
  note: Strain-qualified HM1:IMSS parental trophozoites interacting with live Jurkat
    cells in the 2019 study, not engineered knockdowns, vector controls or every isolate.
    Cell-culture Methods name ATCC as the supplier, without a catalog or lot number.
    The matching HM-1:IMSS collection record at https://www.atcc.org/products/30459
    documents natural clinical isolation from a colonic biopsy; it does not establish
    an exact study lot or clone. NCBI ESearch/EFetch verified the scientific name
    and species rank on 2026-10-06. This taxon ID is species-level, not strain-level.
discussions:
- discussion_id: trogocytosis-scope-and-hierarchy
  prompt: Keep cell nibbling distinct from nutrition and whole-cell uptake.
  kind: CURATION_TODO
  status: OPEN
  rationale: This record concerns the microbe as the nibbling organism, not host immune-cell
    attack on a microbe. Retain phenotype METPO:1000059 pending a closer uptake hierarchy.
    Local phagocytosis traitmech:000627 covers particle enclosure and internalization;
    phagotrophy traitmech:000628 requires nutrient assimilation. Myzocytosis traitmech:000631
    denotes prey-content aspiration through a localized connection, and pallium feeding
    traitmech:000632 involves an enveloping feeding veil. None is asserted equivalent
    or disjoint at organism level. The existing myzocytosis contrast is not an unresolved
    exact trogocytosis node. Neither nutrition, killing, serum protection, a human
    target nor a fixed fragment size is a class requirement. Free-particle uptake
    or attachment alone is insufficient. No unverified synonym or process-level xref
    is asserted.
  posed_by: codex
  posed_date: '2026-10-06'
- discussion_id: trogocytosis-native-mechanism
  prompt: Resolve native molecular mechanisms without universalizing dependencies.
  kind: KNOWLEDGE_GAP
  status: OPEN
  rationale: The two papers are distinct experiments from an overlapping research
    group, not independent taxon replication. Perturbation, localization and sequence
    similarity are different evidence types. Neither a conceptual model nor a homologous
    sequence establishes a universal pathway. Inspect the remaining figures and obtain
    taxon-paired functional and accession evidence before adding protein examples
    or a causal graph.
  posed_by: codex
  posed_date: '2026-10-06'
curation_history:
- timestamp: '2026-10-06T03:16:00Z'
  curator: codex
  action: MINTED_TRAITMECH_ID
  changes: Added trogocytosis with two DOI-backed scientific-abstract snippets and
    an HM1:IMSS-qualified example. Ignored-and-hidden novelty searches and pinned
    METPO review found no exact record. Reserved METPO:1058600 in v509. Kept nutrition,
    killing and serum protection out of the definition and deferred unsupported protein
    mechanisms.
  llm_assisted: true