Thymocyte selection-associated high mobility group box protein mRNA 3' untranslated region (TOX mRNA 3'UTR)

The Thymocyte selection-associated high mobility group box protein (TOX) mRNA 3' untranslated region (3'UTR) is a critical regulatory segment of the TOX transcript, which encodes a key transcription factor driving T cell exhaustion (Khan et al., Nature 2019, https://doi.org/10.1038/s41586-019-1329-0). In the context of chronic antigen exposure, such as in cancer or chronic viral infections, TOX expression is sustained, leading to the epigenetic remodeling of T cells into an exhausted state characterized by high inhibitory receptor expression and reduced effector function (Alfei et al., Nature 2019, https://doi.org/10.1038/s41586-019-1312-9). The 3'UTR contains specific sequences that serve as binding sites for microRNAs, such as miR-181a-5p, which have been shown to regulate TOX levels and influence T cell persistence (Li et al., Cell Reports 2022, https://doi.org/10.1016/j.celrep.2022.111052). These regulatory interactions dictate the half-life and translational efficiency of the TOX message, making the 3'UTR a focal point for post-transcriptional control. Therapeutic targeting of this region via antisense oligonucleotides (ASOs) or miRNA mimics aims to downregulate TOX levels, thereby preventing or reversing T cell exhaustion. This approach is designed to enhance the anti-tumor immune response by maintaining the functionality of tumor-infiltrating lymphocytes. Furthermore, modulating the TOX mRNA 3'UTR is being explored as a method to improve the efficacy of CAR-T cell therapies and immune checkpoint inhibitors. Challenges include ensuring the specificity of RNA-targeting agents and achieving efficient delivery to the relevant immune cell populations within the tumor microenvironment.

Other names

TOX 3'UTRThymocyte selection-associated high mobility group box 3' untranslated regionTOX mRNA 3-prime untranslated regionTOX 3-prime UTR

Reduction of TOX protein expression through antisense-mediated mRNA degradation or microRNA-induced translational repression and mRNA decay.