title: The experimental treatment of corneal graft rejection with the interleukin-1 receptor antagonist (IL-1ra) gene.
abstract: OBJECTIVE
  To investigate the protective effects of interleukin-1 receptor antagonist (IL-1ra) gene transfer in a rat model of corneal graft rejection.
  
  
  METHODS
  We constructed a recombinant plasmid (pcDNA3.1-hIL-1ra) with high IL-1ra expression in eukaryotic cells. Using a Wistar-SD rat model of corneal graft rejection, we examined the effects of IL-1ra in vivo after cationic polymer jetPEI-mediated nonviral gene delivery. Four groups were included: negative controls (group I, n = 20), pcDNA3.1-hIL-1ra corneal stromal injection (group II, n = 34), pcDNA3.1-hIL-1ra anterior chamber injection (group III, n = 34), and 500 µg/ml IL-1ra protein subconjunctiva injection (group IV, n = 20). IL-1ra expression after transfection was evaluated by real-time polymerase chain reaction (RT-PCR) and western blotting. The rejection indices of corneal grafts were analysed in the different groups. The expression levels of transforming growth factor β1 (TGF-β1), inflammatory chemokines including RANTES, interleukin-1 (IL-1) and the numbers of CD4+ and CD8+ T cells in the grafts were determined by biochemical assays at different time points after corneal transplantation.
  
  
  RESULTS
  Various degrees of inflammatory cell infiltration and graft neovascularisation were observed by histopathology. After injecting the pcDNA3.1-hIL-1ra plasmid into the cornea, IL-1ra mRNA and protein expression was detected in the corneal stroma and reached a peak on day 3. The graft survival curves indicated that the corneal transparency rates of grafts in the IL-1ra gene-treated group and the IL-1ra protein-treated group were higher compared with the untreated group (P<0.05). During the period of acute rejection, TGF-β1, RANTES, IL-1α and IL-1β levels in the grafts in the IL-1ra treatment groups were lower than the control group (P<0.05). CD4+ and CD8+ T cell counts were reduced significantly in the corneal grafts of groups II, III and IV compared with group I (P<0.05).
  
  
  CONCLUSIONS
  Interleukin-1 receptor antagonist (IL-1ra) gene transfer treatment inhibits graft rejection after corneal transplantation through the downregulation of immune mediators.
authors.affiliation: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Centre, SunYat-sen University, Guangzhou, Guangdong Province, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Yuan
authors.forename: Yi
authors.initials: Y
authors.lastname: Liu
authors.forename: Weilan
authors.initials: W
authors.lastname: Huang
authors.forename: Shiyou
authors.initials: S
authors.lastname: Zhou
authors.forename: Shiqi
authors.initials: S
authors.lastname: Ling
authors.forename: Jiaqi
authors.initials: J
authors.lastname: Chen
mesh_terms: D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D018946:Chemokine CCL5 / Q000378:metabolism; D003315:Cornea / Q000378:metabolism / Q000601:surgery; D016039:Corneal Transplantation; D015316:Genetic Therapy; D006084:Graft Rejection / Q000276:immunology / Q000628:therapy*; D006085:Graft Survival / Q000276:immunology; D006801:Humans; D053590:Interleukin 1 Receptor Antagonist Protein / Q000235:genetics* / Q000378:metabolism; D053582:Interleukin-1alpha / Q000378:metabolism; D053583:Interleukin-1beta / Q000378:metabolism; D018655:Lymphocyte Count; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D017208:Rats, Wistar; D013997:Time Factors; D016212:Transforming Growth Factor beta / Q000378:metabolism
chemical_list: D018946:Chemokine CCL5; D053590:Interleukin 1 Receptor Antagonist Protein; D053582:Interleukin-1alpha; D053583:Interleukin-1beta; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta