Objective:To investigate the repair effect of bone marrow mesenchymal stem cells(BMSCs)on interferon gamma(IFN-γ)induced ovarian granulosa cell immune injury.Methods:A model of IFN-γ-induced ovarian granulosa cell immune injury was estab-lished.KGN cells after modeling were co-cultured with human BMSCs(hBMSCs)and divided into three groups:negative control(NC)group,IFN-γ group,and BMSC group.After co-culture,cell proliferation was determined by a cell counting kit 8 assay for 3 consecu-tive days.Cell apoptosis was determined using an Annexin V-FITC apoptosis detection kit and a CytoFLEX flow cytometer.The estra-diol level and the mRNA expression levels of aromatase CYP19A1 and FSHR were measured to evaluate the hormone synthesis ability.The level of lactate dehydrogenase(LDH),mRNA expression levels of NLRP3,caspase-1(CASP1),and interleukin-1β,and protein expression levels of NLRP3,CASP1,and gasdermin-D were determined to evaluate cell pyroptosis.Results:The proliferation rate of granulosa cells in the IFN-γ group and the BMSC group was lower than that in the NC group at 24 h,48 h and 72 h,and that in the IFN-γ group was lower than that in the BMSC group(P<0.001).The number of apoptotic granulosa cells in the INF-γ group and the BMSC group was higher than that in the NC group,and that in the INF-γ group was higher than that in the BMSC group(P<0.001).The estradiol level in the INF-γ group and the BMSC group was lower than that in the NC group,and that in the INF-γ group was lower than that in the BMSC group(P<0.001).Compared with the IFN-γ group,the mRNA expression of CYP19A1 and FSHR in the BMSC group decreased(P<0.001).Compared with the IFN-γ group,the BMSC group had significantly decreased LDH level,mRNA expression levels of NLRP3 and CASP1,and protein expres-sion level of CASP1.Conclusion:hBMSCs repair the immune in-jury of KGN cells induced by IFN-γ by restoring cell proliferation,inhibiting cell apoptosis,repairing endocrine function,and reducing pyroptosis.