APRIL/BLyS deficient rats prevent donor specific antibody

APRIL (A proliferation inducing ligand) and BLyS (B Lymphocyte Stimulator) are two critical survival factors for B lymphocytes and plasma cells, the main source of alloantibody. We sought to characterize the specific effects of these cytokines in a kidney transplant model of antibody mediated rejection (AMR). We engineered APRIL.sup.-/- and BLyS.sup.-/- Lewis rats using CRISPR/Cas9. APRIL.sup.-/- and BLyS.sup.-/- rats were sensitized with Brown Norway (BN) blood (complete MHC mismatch). Twenty-one days following sensitization, animals were harvested and collected tissues were analyzed using flow cytometry, ELISPOT, and immunohistochemistry. Flow cross match and a 3 day mixed lymphocyte reaction (MLR) was performed to assess donor specific antibody (DSA) production and T-cell proliferation, respectively. Sensitized dual knock out Lewis rats (APRIL.sup.-/- /BLyS.sup.-/-) underwent kidney transplantation and were sacrificed on day 7 post-transplant. Sensitized BLyS.sup.-/- had significant decreases in DSA and cell proliferation compared to WT and APRIL.sup.-/- (p