A molecular network regulating the pro-inflammatory phenotype of human memory T lymphocytes (Nanostring II)

Understanding the mechanisms that modulate T helper lymphocyte functions is crucial to decipher normal and pathogenic immune responses in humans. To identify molecular determinants influencing the pathogenicity of T cells, we separated ex vivo-isolated primary human memory T lymphocytes based on their ability to produce high levels of inflammatory cytokines. We found that the inflammatory, cytokine-producing phenotype of memory T lymphocytes was defined by a specific core gene signature and was mechanistically regulated by the constitutive activation of the NF-kB pathway and by the expression of the transcriptional repressor BHLHE40. BHLHE40 attenuated the expression of anti-inflammatory factors, including miR-146a, a negative regulator of NF-kB activation, and ZC3H12D, an RNase of the Regnase-1 family able to degrade inflammatory transcripts. Our data reveal a molecular network regulating the pro-inflammatory phenotype of human memory T lymphocytes, with the potential to contribute to disease. Primary human T effector memory cells (Tem) were obtained from 6 donors. Tem cells were PE-labelled for GM-CSF expression with a GM-CSF Cytokine Secretion Assay (Miltenyi Biotec) and sorted for PE+/-. Total RNA of was extracted and 100 ng of RNA were used for the hybridization reagents of the nCounter® Human miRNA Expression Assay (Nanostring). Samples were run on a Nanostring Sprint Profiler and analysed using Nsolver 3.0.