cell
T Cell Subsets
Adaptive decision layer for specificity, memory, tolerance, cytotoxicity, and chronic exhaustion
Review layer
Last reviewed 2026-05-17
Systems teaching draft. Content is structured for education and graph expansion, with formal source tagging ready for the next review pass.
State signature
Systems profile
Graph neighborhood
Direct relationships
TH2 polarization through STAT6 and GATA3
Surveillance can become pathogenic with barrier dysfunction
Antigen presentation with costimulation and cytokine context
Network behavior
Systems Overview
T cells translate antigen context and cytokine ecology into specialized states including TH1, TH2, TH17, Treg, cytotoxic memory, tissue residency, and exhaustion.
Lineage
Origin
HSC -> lymphoid progenitor -> thymocyte -> naive T cell -> effector, memory, regulatory, or exhausted states
Transcription factors: T-bet, GATA3, RORγt, FOXP3, BCL6, TOX, TCF1
Lifecycle Visualizer
weeks
Thymic selection
Central tolerance and TCR selection
months-years
Naive circulation
Antigen-seeking surveillance
days
Effector expansion
Clonal proliferation and subset polarization
weeks-years
Memory or exhaustion
Long-lived recall or chronic antigen adaptation
Activation and Suppression
Surface and Secreted Signals
Metabolic State
Programs
Acute: Activation requires anabolic mTOR signaling and glycolytic expansion.
Chronic: Repeated antigen and inflammatory exposure produce checkpoint expression, mitochondrial strain, and exhaustion.
Tissue Roles
gut: Maintains tolerance while permitting anti-pathogen and TH17 barrier programs.
lung: Balances viral memory, allergy, and tissue-resident surveillance.
skin: Resident memory cells accelerate recall and can sustain inflammatory dermatoses.
CNS: Limited surveillance can become pathogenic when barrier and antigen context shift.
lymphoid: Naive priming, germinal center help, and memory shaping occur in organized niches.
Disease Associations
Clinical Pearls
- T cell patterns are antigen plus context, not antigen alone.
- Exhaustion is an adaptation to chronic stimulation, not simply weakness.
- Tregs and tissue metabolism often determine whether a response becomes protective or destructive.