Role of Natural Killer Cells in Antibody-mediated Rejection of Kidney Transplantation.

Objective: This study explicitly demonstrates the roles of natural killer (NK) cells in different types of kidney transplantation.

Methods: We'd done the whole study from October 2022 to October 2023. To further explore the significance of NK cells during renal transplantation, we provide a theoretical basis for clinically overcoming immune rejection after renal transplantation by developing new anti-rejection drugs. We selected twelve male mice and divided them into three groups (Syngeneic transplant group allograft transplant group allograft transplant (priming) group) by random. Initially, the morphological and histopathological changes in the kidney transplantation graft model of mice in different groups are observed. Further, the DSA-IgG levels in peripheral blood and C3d and IgG deposition in mice are detected by ELISA and immunohistochemical staining. Then, the Banff 2015 score is recorded to screen a suitable AMR mouse model. Finally, the expression of NK cells in different rejection modes is detected by flow cytometry, and the expressions of various cytokines (INF-γ, perforin, granzyme B, TNF-α) in peripheral blood are detected by enzyme-linked immunosorbent assay (ELISA).

Results: In the allogeneic transplantation (priming) group, peritubular capillary inflammatory cell infiltration, moderate endarteritis, and small arterial fibrinoid necrosis are evident. The Banff score showed that the allogeneic transplantation (pre-sensitized) group is significantly higher than the syngeneic and allogeneic transplantation groups. The C3H→C57BL/6 mice are pre-sensitized by skin transplantation, and then kidney transplantation is performed to establish the antibody-mediated rejection (AMR) model. After kidney transplantation, the expression levels of NK cells in the peripheral blood, spleen, and transplanted kidney tissue of mice in the pre-sensitized group are significantly higher than in the allogeneic transplantation and control groups. In the C3H→C57BL/6 mouse model of AMR, NK cells and the related cytokines in the peripheral blood are highly expressed after kidney transplantation, proving that NK cells play an essential role in the occurrence of AMR.

Conclusion: Our study proved the significance of NK cells in the occurrence of AMR by systematically monitoring the expression of NK cell-related cytokines in different types, which provided some ideas for the clinical treatment of AMR.