Antibody Response Against Perlecan and Collagen Types IV and VI in Chronic Renal Allograft Rejection in the Rat

Abstract

Chronic rejection is the leading cause of late renal transplant failure. Various structural lesions are observed in grafts undergoing chronic rejection including glomerular basement membrane (GBM) duplications. The well-established Fisher (F344) to Lewis (LEW) rat renal transplant model for chronic rejection was used to assess the presence and role of the humoral immune response against graft antigens during chronic rejection. LEW recipients of F344 allografts develop transplant glomerulopathy and produce IgG1 antibodies directed against F344 GBM preparations that are detectable 3 weeks after transplantation. Glomerular IgG1 deposition was observed that in vitro co-localized with a rabbit anti-rat GBM antiserum in rejecting F344 grafts; elution experiments of isolated glomeruli yielded IgG1 antibodies reactive in vitro with F344 GBM, but not LEW GBM. 1 The glomeruli may show a myriad of lesions, including chronic transplant glomerulopathy, which is characterized by duplication of the glomerular basement membrane (GBM) with interposition of electron-lucent material.2,3 Transplant glomerulopathy is observed in up to 20% of kidney grafts with CR. 4 It has been postulated that CR results from immune reactions of the recipient against yet poorly defined antigens exposed in the graft. 5 Nonimmune factors, such as hypertension or ischemia/reperfusion injury, may lead to unmasking or alteration of graft antigen(s).1 In syngeneic transplants with comparable degrees of nonimmune injury, CR does not develop within the same time span compared with allogeneic grafts, underlining the importance of immunological mechanisms.6 -8 We hypothesize that immune reactions such as antibody formation after previous damage play a role in the perpetuation of CR in renal allografts. In a mouse model of chronic cardiac graft rejection, antibodies are crucial for disease development.7 Immunoglobulin heavy chain (IGH) knockout mice that receive a cardiac allograft do not develop CR in contrast to immunoglobulin heavy chain wild-type mice.7 Moreover, transfer of posttransplantation (Tx) IgG antibodies or antigen-reactive immune serum into transplanted SCID mice results in transplant atherosclerosis. 6,8 A well-established model to study CR in renal allografts is the F344 to LEW rat model. All LEW recipients of F344 grafts develop acute rejection at approximately day 30 resulting in 50% graft loss. The surviving animals show histopathological and functional characteristics of CR from day 50. The reverse combination, ie, LEW kidneys transplanted into F344 rats all exhibit long-term surviving kidney grafts in the absence of histological abnormalities, despite early acute rejection episodes. In this model, antibody responses specific for lymph node-derived lymphocytes have been described. 9 These antibodies disappeared at 8 weeks after Tx and were described to

Epidermal Growth Factor and Perlecan Fragments Produced by Apoptotic Endothelial Cells Co-Ordinately Activate ERK1/2-Dependent Antiapoptotic Pathways in Mesenchymal Stem Cells

“…Urine proteomic analysis identified LG3 as a novel biomarker of CTV in renal transplant recipients [30,31,58]. The present work demonstrates that LG3 could participate in the pathophysiology of CTV through inhibition of apoptotic pathways in hMSC.…”

“…Perlecan proteolysis has been documented in animal models of renal allograft rejection, and direct evidence of microvascular perlecan Growth differentiation factor-9 precursor gdf9 X Fibroblast growth factor-4 fgf4 X Fibroblast growth factor-17 fgf17 X Melanoma-derived growth regulatory protein precursor Mia X Epidermal growth factor Egf X X Abbreviations: HPLC, high performance liquid chromatography; SDS-PAGE, sodium dodecyl sulfate polyacrylamide gel electrophoresis; SSC-DMSO, serum-free medium conditioned by apoptotic endothelial cells; SSC-ZVAD, serum-free medium conditioned by nonapoptotic edothelial cells. proteolysis in human renal biopsies with evidence of CTV has been reported recently [31,33].…”

“…Endothelial apoptosis triggers the extracellular export of cathepsin L and other proteases, thereby inducing basement membrane proteolysis, a characteristic feature of CTV [3,30,31]. In turn, proteolysis of basement membrane perlecan leads to the production of an antiapoptotic carboxyl-terminal (C-terminal) fragment active on vascular smooth muscle cells and fibroblasts [29,32].…”

Surgical Anatomy and Microvascular Surgical Technique Relevant to Experimental Renal Transplant in Rat Employing Aortic and Inferior Venacaval Conduits

“…2 Experimental RT in rats has played a vital role in enhancing the understanding of the immunologic processes and application of immunosuppressive agents in clinical human RT. [3][4][5] For a successful RT in rats, in addition to paying attention to the pre-, intra-, and postoperative care of donors and recipients, a thorough understanding of the details of the anatomy is mandatory to successfully complete donor nephrectomy and recipient RT procedures.…”

“…2 Experimental RT in rats has played a vital role in enhancing the understanding of the immunologic processes and application of immunosuppressive agents in clinical human RT. [3][4][5] For a successful RT in rats, in addition to paying attention to the pre-, intra-, and postoperative care of donors and recipients, a thorough understanding of the details of the anatomy is mandatory to successfully complete donor nephrectomy and recipient RT procedures.In rats, the anatomy of the retroperitoneum and the blood supply to the kidney, ureter, and bladder resemble those of humans; therefore, the principles of dissection during organ retrieval and implantation are similar. Lack of appropriate experience and skill is conducive to complications in donors and recipients and early transplant failure.…”