Effector T-cell substrate

Effector T-cell substrates refers to the diverse array of intracellular molecules that are modified or cleaved by effector T cells to execute their biological functions, particularly the induction of apoptosis in target cells. The most prominent members of this group are the substrates of Granzyme B, a serine protease released by cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells (Lord et al., 2003, PubMed: 14500320). Upon entry into a target cell, Granzyme B cleaves specific substrates such as pro-caspase-3, the BH3-only protein Bid, and the Inhibitor of Caspase-Activated DNase (ICAD), which triggers the apoptotic cascade (UniProt P10144). Additionally, the term can encompass signaling substrates within the T cell itself, such as LAT (Linker for Activation of T cells) and SLP-76, which are essential for T-cell receptor (TCR) mediated activation (Smith-Garvin et al., 2009, PubMed: 19113754). Because this term describes a functional class of proteins rather than a single molecular entity, it is not classified as a specific therapeutic target. Instead, clinical interventions typically focus on modulating the upstream activation of effector T cells using checkpoint inhibitors like Pembrolizumab or Nivolumab, which ultimately facilitate the engagement of these substrates to eliminate tumor or infected cells.

Other names

Granzyme B substratesCytotoxic T lymphocyte substratesT-cell effector moleculesT-cell signaling substrates

Enhancement of T-cell effector function and delivery of cytotoxic proteases to target cells, resulting in the cleavage of intracellular substrates and induction of apoptosis.