A Cytokine Receptor Signaling Atlas Reveals How STAT Mosaics Fine-Tune T Cell Function

The research team has developed a groundbreaking tool to investigate cytokine receptor signaling in T cells. By engineering a unique orthogonal IL-2/IL-2R{beta}/{gamma}c system, they were able to activate every one of the 36 mammalian cytokine receptors and their six corresponding STATs without interference. At the membrane-proximal level, the team conducted a comprehensive phospho-signaling profiling, which revealed that each receptor activates a dominant STAT.

However, the activation patterns were not uniform; rather, they were influenced by combinatorial biases, leading to unique STAT activation fingerprints that fine-tune nuanced T cell fates.

At the membrane-distal level, the team performed a single-cell transcriptomic atlas of all cytokine receptors, confirming that these STAT mosaics indeed specify non-redundant transcriptional programs. The findings demonstrate that STAT5-dominant receptors drive proliferative expansion, potentially at the expense of stemness. In contrast, STAT3-driven programs instruct a continuum of T cell fates, ranging from stem cell memory to terminal effector states, while preserving cytotoxic capacity.

This enables superior curative antitumor responses. Furthermore, other STATs are responsible for highly restricted phenotypes. The study provides a detailed understanding of the STAT signaling vocabulary, which defines the intrinsic functional bandwidth of natural cytokines.