AUTHOR=Zhang Bo , Feng Huiru , Lin Hui , Li Rui TITLE=Somatostatin-SSTR3-GSK3 modulates human T-cell responses by inhibiting OXPHOS JOURNAL=Frontiers in Immunology VOLUME=Volume 15 - 2024 YEAR=2024 URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2024.1322670 DOI=10.3389/fimmu.2024.1322670 ISSN=1664-3224 ABSTRACT=Somatostatin (SST) is a peptide hormone primarily synthesized in the digestive and nervous systems. While its impact on the endocrine system is well-established, accumulating evidence suggests a crucial role for SST and its analogues in modulating immune responses. Despite this, the precise mechanism through which SST regulates T cells has remained largely unknown. In our study, we explored the effects of SST on human T cells and discovered that it diminishes T-cell proliferation by influencing IL-2 production and T-cell mitochondrial respiration, while having no discernible impact on TCR-induced glycolysis. Our findings also identified that the regulatory influence of SST on T-cell responses and metabolism is contingent on its receptor, SSTR3. Moreover, we demonstrated that SST governs T-cell responses and metabolism by acting through the T-cell metabolic checkpoint GSK3. Collectively, our data provides molecular insights into the immunoregulatory function of SST in human T cells.