T cell receptor signaling (TCR signaling)

T cell receptor (TCR) signaling is a fundamental process in adaptive immunity, enabling T lymphocytes to recognize and respond to specific antigens. The TCR complex, composed of variable α and β chains for antigen recognition and invariant CD3 subunits (ε, γ, δ, ζ) for signal transduction, detects peptide antigens presented by major histocompatibility complex (MHC) molecules on antigen-presenting cells (APCs). Upon engagement with the peptide-MHC complex (pMHC), the TCR initiates a cascade of intracellular signaling events that lead to profound changes in gene expression, cellular metabolism, proliferation, differentiation into effector or memory cells, cytokine production, and cytoskeletal reorganization.

Other names

TCR pathwayT cell activation pathwayT lymphocyte signaling

Various, depending on the specific drug. Examples include: Inhibition of calcineurin (Cyclosporine, Tacrolimus), inhibition of mTOR (Rapamycin), blockade of co-stimulatory signals (CTLA-4 inhibitors), blockade of immune checkpoints (PD-1 inhibitors), T cell depletion (Anti-CD3 antibodies), kinase inhibition (Lck, ZAP70, Itk inhibitors)