ABSTRACT
Antibody-mediated rejection (AMR) is one of the major causes of graft loss after transplantation. Recently, the regulation of B cell differentiation and the prevention of donor-specific antibody (DSA) production have gained increased attention in transplant research. Herein, we established a secondary allogeneic in vivo skin transplant model to study the effects of romidepsin (FK228) on DSA. The survival of grafted skins was monitored daily. The serum levels of DSA and the number of relevant immunocytes in the recipient spleens were evaluated by flow cytometry. Then, we isolated and purified B cells from B6 mouse spleens in vitro by magnetic bead sorting. The B cells were cultured with interleukin-4 (IL-4) and anti-clusters of differentiation 40 (CD40) antibody with or without FK228 treatment. The immunoglobulin G1 (IgG1) and IgM levels in the supernatant were evaluated by enzyme-linked immunosorbent assay (ELISA). Quantitative reverse transcription-polymerase chain reaction (RT-qPCR) and western blotting were conducted to determine the corresponding levels of messenger RNA (mRNA) and protein expression in cultured cells and the recipient spleens. The results showed that FK228 significantly improved the survival of allogeneic skin grafts. Moreover, FK228 inhibited DSA production in the serum along with the suppression of histone deacetylase 1 (HADC1) and HDAC2 and the upregulation of the acetylation of histones H2A and H3. It also inhibited the differentiation of B cells to plasma cells, decreased the transcription of positive regulatory domain-containing 1 (Prdm1) and X-box-binding protein 1 (Xbp1), and decreased the expression of phosphorylated inositol-requiring enzyme 1 α (p-IRE1α), XBP1, and B lymphocyte-induced maturation protein-1 (Blimp-1). In conclusion, FK228 could decrease the production of antibodies by B cells via inhibition of the IRE1α-XBP1 signaling pathway. Thus, FK228 is considered as a promising therapeutic agent for the clinical treatment of AMR.
Subject(s)
Animals , Mice , Depsipeptides , Endoribonucleases , Hematopoietic Stem Cell Transplantation , Histone Deacetylase Inhibitors/pharmacology , Protein Serine-Threonine Kinases , Skin TransplantationABSTRACT
<p><b>OBJECTIVES</b>To simplify the enteric drainage (ED) procedure and to decrease surgical and metabolic complications in simultaneous pancreas-kidney transplantation (SPK) patients.</p><p><b>METHODS</b>Between June 2000 and June 2002, nine patients with insulin-dependent diabetes mellitus (IDDM) and uremia underwent simultaneous pancreas-kidney transplantation. The arterial inflow of the pancreas was based upon the right external iliac artery, while venous drainage was systemic via the external iliac vein. The allografts' exocrine secretions were drained into the proximal jejunum via a two-layer hand sewn, side-to-side donor duodenum to proximal small bowel anastomosis after reperfusion. No Roux-en-Y an astomosis of the jejunum was performed. The kidney graft was placed in the left iliac fossa. Quadruple immunosuppressive therapy with antilymphocyte globulin or anti-CD25 monoclonal antibody (Zenapax), tacrolimus, mycophenolate mofetil and steroids was standard treatment in all patients.</p><p><b>RESULTS</b>This procedure was successfully applied in all 9 patients without complication referable to the technique. All patients had achieved euglycemia and excellent renal function, and stopped being dependent on an external insulin source. Fasting serum glucose fell from 9.5 preoperatively to 4.8 mmol/L and remained stable thereafter. At the time this paper was written, the grafts from eight patients were functioning well.</p><p><b>CONCLUSIONS</b>Our primary experience suggests that SPK with ED without Roux-en-Y anastomosis represents a more physiologic milieu, and a viable alternation to replace the bladder (BD) as the primary route of drainage for exocrine secretions of the pancreas. It is a feasible and safer procedure.</p>