Protein kinase CK2 enables regulatory T cells to suppress excessive [T.sub.H]2 responses in vivo

The quality of the adaptive immune response depends on the differentiation of distinct [CD4.sup.+] helper T cell subsets, and the magnitude of an immune response is controlled by [CD4.sup.+][Foxp3.sup.+] regulatory T cells ([T.sub.reg] cells). However, how a tissue- and cell type-specific suppressor program of [T.sub.reg] cells is mechanistically orchestrated has remained largely unexplored. Through the use of [T.sub.reg] cell-specific gene targeting, we found that the suppression of allergic immune responses in the lungs mediated by T helper type 2 ([T.sub.H]2) cells was dependent on the activity of the protein kinase CK2. Genetic ablation of the β- subunit of CK2 specifically in [T.sub.reg] cells resulted in the proliferation of a hitherto-unexplored [ILT3.sup.+] [T.sub.reg] cell subpopulation that was unable to control the maturation of [IRF4.sup.+][PD-L2.sup.+] dendritic cells required for the development of [T.sub.H]2 responses in vivo.