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 at neutral pH. 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 or the like which express 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 at neutral pH.
