The technology relates generally to the field of immunology and relates in part to methods for activating T cells and other cells resulting in an immune response against a target antigen. The technology also relates to costimulation of therapeutic cells that express chimeric antigen receptors that recognize target antigens using chimeric MyD88- and CD40-derived polypeptides. The technology further relates in part to therapeutic cells that express chimeric antigen receptors, wherein the chimeric antigen receptors have an endodomain that includes MyD88- and CD40-derived polypeptides, and methods for treating patients using the modified therapeutic cells.
