The inventors discovered that an immune response to an antigen was induced in a living organism having an antigen-binding molecule administered thereto, said antigen-binding molecule including an antigen-binding domain wherein the binding activity relative to the antigen changes depending on ion concentration conditions, and an FcRn-binding domain having binding activity to FcRn in pH-neutral range conditions. The inventors also discovered that, in addition to the induced immune response to the antigen, a toxic action or a growth inhibitory action on foreign organisms, cancer cells, and the like expressing the antigen to which said antigen-binding molecule binds was also found in the living organism having the antigen-binding molecule administered thereto, said antigen-binding molecule including the antigen-binding domain wherein the binding activity relative to the antigen changes depending on ion concentration conditions, and the FcRn-binding domain having binding activity to FcRn in pH-neutral range conditions.
