Combination motif immune stimulatory oligonucleotides with improved activity

A class of immunostimulatory nucleic acids having at least two functionally and structurally defined domains is provided. This class of combination motif immunostimulatory nucleic acids activates an immune response and is useful for treating a variety of immune related disorders such as cancer, infectious disease, and allergic disorders. The nucleic acids also stimulate activation of natural killer cells and production of type 1 interferon.