动物造模 z-bio 2022-08-11 239

　　Objective To establish a humanized mouse model of cytotoxic T lymphocyte-associated antigen 4 (CTLA4) gene, and to provide an effective mouse model for the development and screening of tumor therapeutic antibodies targeting CTLA4.

　　Methods Using CRISPR/Cas9 technology, the CTLA4 gene humanized and knockout mouse model was established, and it was identified and analyzed by PCR, RT-PCR, Western Blot, immunohistochemistry and flow cytometry. The mouse melanoma cell line (B16) was injected subcutaneously into CTLA4 humanized mice, and the antitumor effect of intraperitoneal injection of CTLA4 monoclonal antibody ipilimumab was observed.

　　Results CTLA4 humanized mice could stably express human CTLA4 but not murine CTLA4. CTLA4 humanized mice survived normally within 6 months after birth, with no obvious abnormalities in histopathology and immune system. At the same time, in CTLA4 humanized mice, ipimide slowed tumor growth rate. CTLA4 knockout mice do not express the CTLA4 gene and die from autoimmune diseases within 3 to 5 weeks after birth.

　　Conclusion CTLA4 humanized and knockout mice were established simultaneously. CTLA4 humanized mice can be used to screen for therapeutic antibodies or drugs related to the CTLA4 gene.