Component
Human interferon gamma / IFNG
Context-specific entity; species, compartment and exposure are stated on each claim.
6 recorded relationships. Experimental role, claim status and evidence remain attached to each record.
How nutrients influence it
Every nutrient with a recorded effect on this component, credited to the nutrient that acted rather than the chapter that recorded it. Open a nutrient to see the findings and the conditions they were measured under.
Other things that act on it
Enzymes, hormones, genes, and other components with a recorded effect. These are not nutrients, so they do not count toward the arrows above. Each finding names the chapter that recorded it.
How nutrients reach it in more than one step
Chains of two or more recorded steps that end here, grouped by the nutrient they start from. Each step is a separate finding, so a chain is a route a mechanism could take, not proof that it does.
Tracing routes…
What it does
Every recorded relationship this component is part of, grouped by its role. Plain wording comes first; the technical statement follows.
What it acts on
IFN-gamma induced IDO activity and depleted almost all culture-medium tryptophan over two to three days in responsive human KB and WiDr cells.
Experimental context and source evidence
- evidence_access
- Primary abstract
- experimental_model
- Human cancer-cell cultures.
- limitations
- Other tested cell lines lacked this induced enzyme response; not a universal effect of every interferon exposure.
- nutrient_topic
- Tryptophan collection; molecular form, preparation, species, exposure and manipulation remain explicit. · L-Tryptophan
- plain_language
- An immune signal can locally consume the available amino acid.
- primary_references
- Induction of indoleamine 2,3-dioxygenase: a mechanism of the antitumor activity of interferon gamma. · 1988 · https://pubmed.ncbi.nlm.nih.gov/3124115/ · DOI 10.1073/pnas.85.4.1242
Tryptophan: transport, protein synthesis, neuroactive metabolites, NAD and microbial pathways (2026-09-19) · lines 322–328
AI-assisted research curation; primary-abstract references and experimental limitations individually identified. Not publisher full text. · supports · Human cancer-cell cultures. · source_derived_draft · unverified_draft
## tryptophan-ifng-ido-depletion An immune signal can locally consume the available amino acid. IFN-gamma induced IDO activity and depleted almost all culture-medium tryptophan over two to three days in responsive human KB and WiDr cells. Model: Human cancer-cell cultures. Limitations: Other tested cell lines lacked this induced enzyme response; not a universal effect of every interferon exposure. Evidence access: Primary abstract Induction of indoleamine 2,3-dioxygenase: a mechanism of the antitumor activity of interferon gamma. · 1988 · https://pubmed.ncbi.nlm.nih.gov/3124115/ · DOI 10.1073/pnas.85.4.1242
Complete structured claim and evidence
Where it participates (unsigned role)
CD40 ligand increased IFN-gamma-driven tryptophan catabolism in human monocyte-derived macrophages.
Experimental context and source evidence
- evidence_access
- Primary full text, Figure 5
- experimental_model
- Human macrophage and activated-T-cell coculture.
- limitations
- Not evidence that systemic tryptophan intake determines every immune response.
- nutrient_topic
- Tryptophan collection; molecular form, preparation, species, exposure and manipulation remain explicit. · L-Tryptophan
- plain_language
- Two immune signals jointly increased local consumption.
- primary_references
- Inhibition of T cell proliferation by macrophage tryptophan catabolism. · 1999 · https://pubmed.ncbi.nlm.nih.gov/10224276/ · DOI 10.1084/jem.189.9.1363
Tryptophan: transport, protein synthesis, neuroactive metabolites, NAD and microbial pathways (2026-09-19) · lines 346–352
AI-assisted research curation; primary-abstract references and experimental limitations individually identified. Not publisher full text. · supports · Human macrophage and activated-T-cell coculture. · source_derived_draft · unverified_draft
## tryptophan-cd40-ifng-ido Two immune signals jointly increased local consumption. CD40 ligand increased IFN-gamma-driven tryptophan catabolism in human monocyte-derived macrophages. Model: Human macrophage and activated-T-cell coculture. Limitations: Not evidence that systemic tryptophan intake determines every immune response. Evidence access: Primary full text, Figure 5 Inhibition of T cell proliferation by macrophage tryptophan catabolism. · 1999 · https://pubmed.ncbi.nlm.nih.gov/10224276/ · DOI 10.1084/jem.189.9.1363
Complete structured claim and evidenceAdding tryptophan reversed IFN-gamma-associated growth suppression in KB cells in a dose- and time-dependent manner.
Experimental context and source evidence
- availability_state
- nutrient_deficiency Imported condition classification; unverified.
- evidence_access
- Primary abstract
- experimental_model
- Human KB culture after IFN-gamma.
- limitations
- Not a recommendation to support tumor growth with supplementation.
- nutrient_topic
- Tryptophan collection; molecular form, preparation, species, exposure and manipulation remain explicit. · L-Tryptophan
- plain_language
- Replacement helped where deprivation was the limiting mechanism.
- primary_references
- Induction of indoleamine 2,3-dioxygenase: a mechanism of the antitumor activity of interferon gamma. · 1988 · https://pubmed.ncbi.nlm.nih.gov/3124115/ · DOI 10.1073/pnas.85.4.1242
- trigger_kind
- nutrient_deficiency Imported condition classification; unverified.
Tryptophan: transport, protein synthesis, neuroactive metabolites, NAD and microbial pathways (2026-09-19) · lines 330–336
AI-assisted research curation; primary-abstract references and experimental limitations individually identified. Not publisher full text. · supports · Human KB culture after IFN-gamma. · source_derived_draft · unverified_draft
## tryptophan-kb-repletion Replacement helped where deprivation was the limiting mechanism. Adding tryptophan reversed IFN-gamma-associated growth suppression in KB cells in a dose- and time-dependent manner. Model: Human KB culture after IFN-gamma. Limitations: Not a recommendation to support tumor growth with supplementation. Evidence access: Primary abstract Induction of indoleamine 2,3-dioxygenase: a mechanism of the antitumor activity of interferon gamma. · 1988 · https://pubmed.ncbi.nlm.nih.gov/3124115/ · DOI 10.1073/pnas.85.4.1242
Complete structured claim and evidenceIFN-gamma/IDO-driven tryptophan depletion reduced S6K phosphorylation in human HeLa cells; tryptophan repletion restored the mTOR readout.
Experimental context and source evidence
- availability_state
- nutrient_deficiency Imported condition classification; unverified.
- evidence_access
- Primary full text, Figure 2
- experimental_model
- Human HeLa cells, depleted media and amino-acid add-back.
- limitations
- S6K phosphorylation is a pathway readout, not direct tryptophan binding to MTOR.
- nutrient_topic
- Tryptophan collection; molecular form, preparation, species, exposure and manipulation remain explicit. · L-Tryptophan
- plain_language
- Local depletion reduced a growth signal as well as changing metabolite supply.
- primary_references
- IDO inhibits a tryptophan sufficiency signal that stimulates mTOR: A novel IDO effector pathway targeted by D-1-methyl-tryptophan. · 2012 · https://pubmed.ncbi.nlm.nih.gov/23264892/ · DOI 10.4161/onci.21716
- trigger_kind
- nutrient_deficiency Imported condition classification; unverified.
Tryptophan: transport, protein synthesis, neuroactive metabolites, NAD and microbial pathways (2026-09-19) · lines 402–408
AI-assisted research curation; primary-abstract references and experimental limitations individually identified. Not publisher full text. · supports · Human HeLa cells, depleted media and amino-acid add-back. · source_derived_draft · unverified_draft
## tryptophan-trp-mtor Local depletion reduced a growth signal as well as changing metabolite supply. IFN-gamma/IDO-driven tryptophan depletion reduced S6K phosphorylation in human HeLa cells; tryptophan repletion restored the mTOR readout. Model: Human HeLa cells, depleted media and amino-acid add-back. Limitations: S6K phosphorylation is a pathway readout, not direct tryptophan binding to MTOR. Evidence access: Primary full text, Figure 2 IDO inhibits a tryptophan sufficiency signal that stimulates mTOR: A novel IDO effector pathway targeted by D-1-methyl-tryptophan. · 2012 · https://pubmed.ncbi.nlm.nih.gov/23264892/ · DOI 10.4161/onci.21716
Complete structured claim and evidenceUnder IFN-gamma/IDO1-associated tryptophan shortage, human cancer cells continued translation with WARS1-associated phenylalanine incorporation at tryptophan positions.
Experimental context and source evidence
- availability_state
- nutrient_deficiency Imported condition classification; unverified.
- evidence_access
- Primary abstract; primary correction full text reviewed
- experimental_model
- Human cancer-cell depletion, molecular assays and tumor proteomics.
- limitations
- Not a DNA mutation or a universal consequence of a low-tryptophan meal. Tumor proteomic filtering was clarified in a correction. Correction record: The 2022 author correction adds omitted funding acknowledgements and clarifies that the maximum-sample peptide filter was used in the intra-tumour analysis (Fig. 3f) but not for W>F substitutants in the tumour-specific analysis (Fig. 3a). Authors report similar biological conclusions with both strategies. This is a publication correction, not an opposing mechanism claim. https://www.nature.com/articles/s41586-022-05097-y
- nutrient_topic
- Tryptophan collection; molecular form, preparation, species, exposure and manipulation remain explicit. · L-Tryptophan
- plain_language
- Severe local shortage can change what a cancer cell puts into a protein.
- primary_references
- Tryptophan depletion results in tryptophan-to-phenylalanine substitutants. · 2022 · https://pubmed.ncbi.nlm.nih.gov/35264796/ · DOI 10.1038/s41586-022-04499-2
- trigger_kind
- nutrient_deficiency Imported condition classification; unverified.
Tryptophan: transport, protein synthesis, neuroactive metabolites, NAD and microbial pathways (2026-09-19) · lines 122–128
AI-assisted research curation; primary-abstract references and experimental limitations individually identified. Not publisher full text. · supports · Human cancer-cell depletion, molecular assays and tumor proteomics. · source_derived_draft · unverified_draft
## tryptophan-w-to-f-shortage Severe local shortage can change what a cancer cell puts into a protein. Under IFN-gamma/IDO1-associated tryptophan shortage, human cancer cells continued translation with WARS1-associated phenylalanine incorporation at tryptophan positions. Model: Human cancer-cell depletion, molecular assays and tumor proteomics. Limitations: Not a DNA mutation or a universal consequence of a low-tryptophan meal. Tumor proteomic filtering was clarified in a correction. Correction record: The 2022 author correction adds omitted funding acknowledgements and clarifies that the maximum-sample peptide filter was used in the intra-tumour analysis (Fig. 3f) but not for W>F substitutants in the tumour-specific analysis (Fig. 3a). Authors report similar biological conclusions with both strategies. This is a publication correction, not an opposing mechanism claim. https://www.nature.com/articles/s41586-022-05097-y Evidence access: Primary abstract; primary correction full text reviewed Tryptophan depletion results in tryptophan-to-phenylalanine substitutants. · 2022 · https://pubmed.ncbi.nlm.nih.gov/35264796/ · DOI 10.1038/s41586-022-04499-2
Complete structured claim and evidenceAdded tryptophan did not reverse IFN-gamma growth suppression in WiDr cells despite induced tryptophan catabolism.
Experimental context and source evidence
- availability_state
- nutrient_deficiency Imported condition classification; unverified.
- evidence_access
- Primary abstract
- experimental_model
- Human WiDr culture.
- limitations
- This experimentally observed context difference is not a contradiction requiring a universal single explanation.
- nutrient_topic
- Tryptophan collection; molecular form, preparation, species, exposure and manipulation remain explicit. · L-Tryptophan
- plain_language
- Another cell type retained suppression after the nutrient was replaced.
- primary_references
- Induction of indoleamine 2,3-dioxygenase: a mechanism of the antitumor activity of interferon gamma. · 1988 · https://pubmed.ncbi.nlm.nih.gov/3124115/ · DOI 10.1073/pnas.85.4.1242
- trigger_kind
- nutrient_deficiency Imported condition classification; unverified.
Tryptophan: transport, protein synthesis, neuroactive metabolites, NAD and microbial pathways (2026-09-19) · lines 338–344
AI-assisted research curation; primary-abstract references and experimental limitations individually identified. Not publisher full text. · supports · Human WiDr culture. · source_derived_draft · unverified_draft
## tryptophan-widr-repletion-fails Another cell type retained suppression after the nutrient was replaced. Added tryptophan did not reverse IFN-gamma growth suppression in WiDr cells despite induced tryptophan catabolism. Model: Human WiDr culture. Limitations: This experimentally observed context difference is not a contradiction requiring a universal single explanation. Evidence access: Primary abstract Induction of indoleamine 2,3-dioxygenase: a mechanism of the antitumor activity of interferon gamma. · 1988 · https://pubmed.ncbi.nlm.nih.gov/3124115/ · DOI 10.1073/pnas.85.4.1242
Complete structured claim and evidence
The events it takes part in
A mechanism often involves more than two components. These are the full events, with every participant and its role.
Situations it appears in
Low-supply and faulty-machinery situations recorded in the chapters where this component plays a part.
In the sources
Preserved passages that mention this component, quoted exactly. Open one to read it in context.
Open hypotheses
Proposed ideas that involve this component. They are labeled as hypotheses and do not change any recorded statement.
This is a research prototype built from draft material. It is not medical advice, and its statements still await verification against the original studies.