The nature of gut intraepithelial lymphocytes (IELs) lacking antigen receptors remains controversial. Herein we showed that, in humans and in mice, innate intestinal IELs expressing intracellular CD3 (iCD3(+)) differentiate along an Id2 transcription factor (TF)-independent pathway in response to TF NOTCH1, interleukin-15 (IL-15), and Granzyme B signals. In NOTCH1-activated human hematopoietic precursors, IL-15 induced Granzyme B, which cleaved NOTCH1 into a peptide lacking transcriptional activity.
View Article and Find Full Text PDFIn a previous study, we analysed the synthesis and properties of a series of imidazo[1,2-alpha]quinoxalines designed in our laboratory as possible imiquimod analogues. We found that these imidazo[1,2-alpha]quinoxalines were in fact potent inhibitors of phosphodiesterase 4 enzymes (PDE4). PDE4 inhibition normally results in an increase in intracellular cAMP which, in PBMC, induces the suppression of TNF-alpha mRNA transcription and thus cytokine synthesis.
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