IL-2 orthologs and methods of use

The present disclosure relates to hIL2 orthogonal ligands (“IL2 orthologs”) that specifically and selectively bind to the extracellular domain (ECD) a transmembrane polypeptide comprising of a modified hCD122 polypeptide. The binding of the hIL2 ortholog to the modified hCD122 polypeptide participates in the transduction pathway of intracellular signaling resulting in a biological activity of the native intracellular signaling patterns associated with hIL2 binding to either the intermediate or high affinity hIL2 receptor but which exhibits selectivity to an engineered cell expressing an hCD122 orthogonal receptor. The hIL2 orthologs of the present invention exhibit significantly reduced binding relative to their binding to the extracellular domain of wild type hCD122, either alone or when hCD122 is present in the form of an endogenous high or intermediate affinity hIL2 receptors.