The invention discloses stem cells for specifically expressing a
programmed death receptor 1 (PD-1), and particularly relates to the stem cells from an organic cavity. The stem cells comprise but notlimited to
dental pulp stem cells, gingival mesenchymal steam cells (GMSCs),
periodontal ligament stem cells (PDLSCs), stem cells of apical papilla (SCAPs) and dental
follicle stem cells (DFSCs) or any combination thereof, and preferably comprise stem cells from human exfoliated
deciduous teeth (SHED) and / or dental pulp mesenchymal stem cells for permanent teeth (DPSC); the stem cells also includemesenchymal stem cells from other tissues, which do not express the PD-1 at first and express the PD-1 after being modified by
CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats), suchas PD-1 plus bone mesenchymal stem cells (BMMSC) modified by the
CRISPR. The invention further discloses an identifying and separating method for the stem cells for specifically expressing the PD-1,a method for preparing the PD-1 plus mesenchymal stem cells modified by the
CRISPR as well as application of the mesenchymal stem cells for expressing the PD-1, disclosed by the invention, in tissue regeneration,
pain relief and treatment of
chronic pain and a series of diseases.