Synergizing Translational Repression Versus RNA Degradation by miRNAs during T Cell Activation [RIBOseq]

T cells, crucial for immune regulation, risk malfunction leading to immune deficiencies or autoimmune diseases. Understanding the molecular cycle of T cell activation is vital for potential therapeutic interventions. Activation remodels the cellular transcriptome and proteome, impacting metabolism and protein synthesis pathways. The human genome encodes microRNAs (miRNAs), regulating hundreds of protein-coding mRNAs through translational repression and mRNA decay. While mRNA degradation is terminal, translational repression is reversible, allowing rapid responses to internal or external cues. In this study, we investigated changes in the miRNA repertoire and their impact on translational repression and mRNA degradation during T cell activation using high-throughput techniques. Our findings reveal that miRNAs induced upon T cell activation clear their targets through multiple pathways, with some following the canonical path of mRNA degradation and others initiating translational repression before mRNA degradation. Overall design: mRNAseq, Ribosome profiling and smallRNAseq experiments were carried out with non-activated Jurkat cells or Jurkat cells activated for 5 hr and 12 hr with anti-CD3/anti-CD28 antibodies (Tonbo). For activation, flat bottom plates were coated with anti-CD3 antibody at a 10 µg/mL concentration at 4C for at least 12h, and anti-CD28 antibody was added to the cell culture media at a concentration of 5 µg/mL and cells were incubated for the required timepoints. All experiments had 3 biological replicates and control samples were non activated Jurkat cells.