The present invention relates to a cell therapeutic agent for treating inflammatory diseases caused by hyper-immune responses and, more specifically, to a composition for treating inflammatory diseases caused by hyper-immune responses, containing: (i) cartilage cells or cells, which can be differentiated into cartilage cells and (ii) cartilage cells into which a gene encoding TGF-β is introduced or cells, which can be differentiated into cartilage cells into which a gene encoding TGF-β is introduced.
