Disclosed herein are cells that are immunoinhibitory cell, which cells recombinantly express a dominant negative form of an inhibitor of a cell-mediated immune response of the cell. In certain embodiments, the immunoinhibitory cell is a regulatory T cell. In another aspect, provided herein is a regulatory T cell that recombinantly expresses a dominant negative form of an inhibitor of a regulatory T cell-mediated immune response. The cells can be sensitized to an antigen that is the target of a pathologic immune response associated with an immune-mediated disorder. Additionally provided are methods of using such cells to treat an immune-mediated disorder in a subject in need thereof.