Dynamic characterization of immune response in gene-edited pig-monkey xenotransplantation cardiac model

Objective To investigate the regulatory effect of combined immunosuppression regimen on the peripheral immune cells, cytokines and local immune microenvironment of gene-edited porcine-monkey xenotransplant heart transplant recipients, and to reveal the potential mechanism of xenograft rejection and the regulatory effect of immunosuppressants.Methods Two parallel gene-edited porcine-monkey cardiac xenograft models were constructed in our hospital, and peripheral blood was dynamically collected before and after surgery to detect blood routine, humoral immunity, flow cytometry lymphocyte clustering and cytokines, and cardiac tissues were collected for immunohistochemical detection after the experiment was terminated.Results The first immunosuppressive regimen (B cell clearance, T cell inhibition, complement C3 inhibition) could rapidly reduce lymphocyte levels, but had poor regulatory effects on antibody-mediated rejection and macrophage infiltration. In the second case, the immunosuppressive regimen introduced multiple targets (complement C5 inhibition and IL-6 inhibition) on the basis of the first case, which significantly inhibited humoral immunity and complement activation and reduced antibody deposition, but the late cytokine storm and T cell residue suggest that cellular immune regulation still needs to be optimized.Conclusions The first regimen is simple to operate but has limited efficacy, and the second regimen has more potential in reducing the risk of hyperacute and acute rejection, but its complex drug combination may increase the risk of toxicity and infection, and it is necessary to continuously adjust and optimize the immunosuppressive regimen using dynamic multidimensional monitoring. The introduction of new immune markers donor-derived cell-free DNA (dd-cfDNA), PBMC gene expression profile (GEP), etc., as well as vascular endothelial injury markers (such as soluble P selectin, vWF) and fibrosis indicators (such as TGF-β1), combined with imaging (such as intravascular ultrasound) to achieve multimodal monitoring of chronic rejection will also become the focus of the future.