Immune-mediated Injury (immune-mediated + injury)

Distribution by Scientific Domains


Selected Abstracts


Treatment by Mycophenolate Mofetil of Advanced Graft Vascular Disease in Non-Human Primate Recipients of Orthotopic Aortic Allografts

AMERICAN JOURNAL OF TRANSPLANTATION, Issue 7 2003
Jochen Klupp
Failure to control chronic graft dysfunction [e.g. graft vascular disease (GVD)] is the primary cause of immunologic graft failure. This is the first study of mycophenolate mofetil (MMF) for the treatment of GVD in non-human primate recipients of aortic allografts. Abdominal aortic allografts were exchanged between mixed leukocyte reaction (MLR) -mismatched, blood-group-compatible cynomolgus monkeys. Six control recipients were untreated. Individualized treatment with frequent dose adjustments of MMF insured that treatment was close to the maximum tolerated dose (mean 99.2 mg/kg/day). Immune-mediated injury proceeded unhindered until day 45, after which MMF treatment began. Changes in intimal volume (IV) were quantified by intravascular ultrasound (IVUS) and compared to histology on day 105. Serial IVUS measurements of IV (mm3) in controls showed progressive GVD. In four out of six animals, MMF was well tolerated, thus enabling optimum treatment; in all these animals, IV was significantly less than in the control animals (p = 0.02). In the two remaining animals, high doses were not tolerated; at day 105, there was no significant difference in IV between them and the controls. We found a significant correlation between the mean MMF tolerated dose and the inhibition of progression of IV (r = ,0.88, p = 0.015). When high MMF doses were tolerated, MMF slowed progression of GVD. [source]


Cholangiocytes as immune modulators in rotavirus-induced murine biliary atresia

LIVER INTERNATIONAL, Issue 8 2009
Barrett H. Barnes
Abstract Background/Aims: Biliary atresia (BA) is a progressive disease characterized by bile duct inflammation and fibrosis. The aetiology is unknown and may be due to a virus-induced, autoimmune-mediated injury of cholangiocytes. Cholangiocytes are not only targets of injury but may also modulate hepatic inflammation. The aim of this study was to determine the immune profile of murine cholangiocytes and the ability to function as antigen-presenting cells (APCs) in culture with Rhesus rotavirus (RRV), poly I:C (viral mimic) or interferon-,/tumour necrosis factor-,. Methods/Results: Both the cholangiocyte cell line (long-term culture) and fresh, ex vivo cholangiocytes expressed APC surface markers major histocompatibility complex (MHC)-class I and II and CD40, while only the cultured cell line expressed costimulatory molecules B7-1 and B7-2. Despite APC expression, cultured cholangiocytes were unable to function as competent APCs in T-cell proliferation assays. Furthermore, both cultured and ex vivo cholangiocytes expressed RNA transcripts for many pro-inflammatory cytokines and chemokines. Conclusions: Although cholangiocytes contain APC molecules, they are incompetent at antigen presentation and cannot elicit effective T-cell activation. Upregulation of MHC-class I and II found in BA mice may serve to prime the cholangiocyte as a target for immune-mediated injury. Cholangiocytes produced many pro-inflammatory cytokines and chemokines in the setting of RRV infection and T-helper type 1 cytokine milieu, suggesting a role of cholangiocytes as immune modulators promoting the ongoing inflammation that exists in RRV-induced BA. [source]


Mycophenolate Mofetil Is Associated with Altered Expression of Chronic Renal Transplant Histology

AMERICAN JOURNAL OF TRANSPLANTATION, Issue 2 2007
B. J. Nankivell
Mycophenolate mofetil (MMF) reduces acute rejection in controlled trials of kidney transplantation and is associated with better registry graft survival. Recent experimental studies have demonstrated additional antifibrotic properties of MMF, however, human histological data are lacking. We evaluated sequential prospective protocol kidney biopsies from two historical cohorts treated with cyclosporine (CSA)-based triple therapy including prednisolone and either MMF (n = 25) or azathioprine (AZA, n = 25). Biopsies (n = 360) were taken from euglycemic kidney-pancreas transplant recipients. Histology was independently assessed by the Banff schema and electron microscopic morphometry. MMF reduced acute rejection and OKT3 use (p < 0.05) compared with AZA. MMF therapy was associated with limited chronic interstitial fibrosis, striped fibrosis and periglomerular fibrosis (p < 0.05,0.001), mesangial matrix accumulation (p < 0.01), chronic glomerulopathy scores (p < 0.05) and glomerulosclerosis (p < 0.05). MMF was associated with delayed expression of CSA nephrotoxicity, reduced arteriolar hyalinosis, striped fibrosis and tubular microcalcification (p < 0.05,0.001). The beneficial effects of MMF remained in recipients without acute rejection. Retrospective analysis shows that MMF therapy was associated with substantially reduced fibrosis in the glomerular, microvascular and interstitial compartments, and a delayed expression of CSA nephrotoxicity. These outcomes may be due to a limitation of immune-mediated injury and suggest a direct effect of reduced fibrogenesis. [source]


Recruitment of CXCR3+ and CCR5+ T Cells and Production of Interferon-,-Inducible Chemokines in Rejecting Human Arteries

AMERICAN JOURNAL OF TRANSPLANTATION, Issue 6 2005
William R. Burns
Chemokine receptors preferentially expressed by Th1 cells and their IFN-,-inducible ligands predominate in experimental and clinical allograft rejection. Previous chemokine-related transplantation studies have focused on parenchymal and microvascular inflammation which are of importance in acute rejection, but are not necessarily relevant in immune-mediated injury of conduit arteries. We have recently described a model of progressive human T cell-mediated infiltration and injury of allogeneic coronary artery segments using immunodeficient mouse hosts. In the present study, we investigated if recruitment of allogeneic T cells to different vascular compartments correlated with the expression of chemokines and their receptors. Transcripts were quantified by laser capture microdissection/real-time RT-PCR and their distribution was correlated to the corresponding protein expression detected by immunohistochemistry. Infiltrating T cells, confined to the adventitia and intima, expressed CXCR3 and CCR5, but were not recruited into the media despite production by vascular smooth muscle cells of IP-10, Mig, I-TAC, RANTES and MIP-1,. Chemokine mRNA was detected primarily in vascular cells, although chemokine protein largely localized to infiltrating leukocytes which uniquely expressed their cognate receptors. These data explain the recruitment of IFN-,-secreting T cells to the vessel wall, and reinforce the suggestion that the arterial media may be a site of immunological privilege. [source]