Provided is a non-human mammal obtained by somatic cell nuclear transfer using a CD4+ T cell nucleus as the nuclear donor. Also provided are the offspring of the non-human mammal. The non-human mammal reliably and efficiently exhibits a specific allergic reaction to a variety of antigens, such as mites and Japanese cedar pollen, that have been linked to immunoallergic diseases. Therefore, the non-human mammal can be suitably used in research into a variety of diseases by investigating the possibility of applying the non-human mammal to allergic diseases as an onset model of said diseases.
