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

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 memory cells (Tmem) were obtained from 3 donors. Tmem were were activated with plate-bound aCD3 and aCD28 for 2 days, removed from stimuli and lentivirally transduced with lv-Bhlhe40 or lv-empty. Cells were cultured for 10 more days and from day 5 on the media was supplemented with IL-2 (50U, provided by the institute). During this time cells were selected twice with puromycin (2 ug/ml, Sigma-Aldrich) for 24h.