Engineering T cell-selective chemokine inhibitors through network-level directed evolution

Abstract Immune-mediated inflammatory diseases (IMIDs) are sustained by chemokine-driven recruitment of effector T cells. Although direct suppression of T cell function can be effective, systemic immunosuppression and infection risk limit clinical utility. Targeting chemokine networks offers an alternative strategy, yet chemokine redundancy has hindered the development of clinically effective inhibitors. Tick evasins overcome chemokine redundancy by binding multiple chemokines. Here we show that network-level directed evolution of class B evasin-derived peptides generates T cell-selective chemokine inhibitors. In contrast to analogous class A-derived peptides, these preferentially bind and inhibit chemokines that drive T cell migration. Structural modelling of chemokine:peptide complexes and structure-guided mutagenesis suggest that evasin-derived peptides sterically occlude receptor-binding surfaces and that class B-derived peptides exhibit a more compact organisation of key interaction hotspots than a previously characterised class A-derived peptide. Together, these findings suggest that anti-chemokine peptide specificity can be engineered through scaffold choice and network-level directed evolution.