Regulatory T-cell (Treg) suppression & the IL-2 axis

Regulatory T cells (Tregs) enforce peripheral tolerance and are enriched in tumours, where they blunt anti-tumour responses. Their identity depends on the transcription factor FOXP3, induced and sustained by IL-2 signalling: IL-2 binds the high-affinity receptor (CD25 / IL-2Rα plus CD122 and γc), activating JAK1 / JAK3 and STAT5, which — together with TCR-driven NFAT — drives FOXP3 and reinforces CD25 and CTLA-4.

Tregs suppress effector T cells through several routes: as an IL-2 sink (their high-affinity CD25 out-competes effectors for IL-2), by CTLA-4 trans-endocytosis of CD80/86 from dendritic cells (removing co-stimulation), and by secreting the inhibitory cytokines IL-10 and TGF-β. The net effect is reduced effector proliferation and cytokine output.

Assay Genie In Vivo functional-grade antibodies target this axis two ways: depletion (anti-CD25, anti-CTLA-4) and suppression blockade (anti-IL-2 / IL-2 complexes, anti-IL-10, anti-TGF-β, anti-CD127), both used to relieve Treg-mediated immunosuppression in vivo. For research use only; not for diagnostic or therapeutic procedures. Mouse targets shown.