T-cell costimulation pathway

The T-cell costimulation pathway refers to the network of receptor-ligand interactions on T cells and antigen-presenting cells (APCs) that provide a "second signal" required for full T-cell activation in addition to TCR-peptide-MHC engagement. The best-characterized costimulatory pathway is the CD28 (on T cells) interaction with CD80/CD86 (on APCs), but other notable molecules include members of the immunoglobulin superfamily (e.g., CD28, ICOS) and tumor necrosis factor receptor (TNFR) superfamily (e.g., OX40, 4-1BB, CD27, CD40L)[1][2]. These pathways are essential for regulating T cell proliferation, cytokine production, survival, development of memory and effector functions, as well as immune tolerance and autoimmunity. Some of these interactions result in activation (costimulation), while others lead to inhibition (coinhibition), and both classes are essential for maintaining immune balance[1][2]. The pathway as a whole is a key therapeutic target in autoimmune disorders, transplantation, infection, and cancer immunotherapy[2][4]. The term "T-cell costimulation pathway" does not indicate a specific, individual molecular target but rather includes many distinct receptor-ligand pairs (e.g., CD28/CD80-CD86, ICOS/ICOSL, CD40/CD40L, PD-1/PD-L1), each of which may be considered separately as a therapeutic target[1][2]. For structured data, it is essential to clarify if you want a specific member (like "CD28" or "OX40" etc.), as "T-cell costimulation pathway" is not a canonical molecular entity.

Other names

T-cell co-stimulatory pathwayT-cell costimulatory signalingT-cell co-signaling pathways

Competitive inhibition of costimulatory receptor-ligand binding (e.g. CTLA-4-Ig inhibits CD28 binding to CD80/CD86); Agonism or antagonism of costimulatory receptors (e.g. OX40 agonists, CD40 inhibitors); Modulation of T-cell activation, survival, and cytokine production.