Time-dependent regulation of cytokine production by RNA binding proteins defines T cell effector function

Effective T cell responses against target cells require controlled production of the key pro-inflammatory cytokines IFN-γ, TNF and IL-2. Post-transcriptional events determine the magnitude and duration of cytokine production in T cells, a process that is largely regulated by RNA binding proteins (RBPs). Here we studied the identity and mode of action of RBPs interacting with cytokine mRNAs. With an RNA aptamer-based capture assay from human T cell lysates, we identified >130 RBPs interacting with the full length 3’untranslated regions of IFNG , TNF and IL2. The RBP landscape altered upon T cell activation. Furthermore, RBPs display temporal activity profiles to control cytokine production. Whereas HuR promotes early cytokine production, the peak production levels and response duration is controlled by ZFP36L1, ATXN2L and ZC3HAV1. Importantly, ZFP36L1 deletion boosts T cell responses against tumors in vivo, revealing the potential of the RBP map to identify critical modulators of T cell responses. ### Competing Interest Statement The authors have declared no competing interest.