title: Systemic application of sphingosine 1-phosphate receptor 1 immunomodulator inhibits corneal allograft rejection in mice.
abstract: OBJECTIVE
  This study aims to investigate the effects of systemic application of sphingosine 1-phosphate receptor 1(S1P1) on allogeneic corneal transplantation in mice.
  
  
  METHODS
  A total of 112 BALB/c mice received corneal grafts from C57BL/6 donors. Recipients were randomly divided into seven groups and treated with intraperitoneal injections of S1P1 (5 mg/kg/days), cyclosporine A (5 mg/kg/days), dexamethasone (1 mg/kg/days) and rapamycin (2 mg/kg/days). S1P1was combined with rapamycin or cyclosporine A, and saline served as negative control. Serum levels of IL-2, IL-10, TGF-β1 and IFN-γ were measured by Elisa. The numbers of CD4+ T and regulatory (Treg) cell phenotype were measured by flow cytometry. Cytokine mRNA expression was analysed by real-time quantitative PCR. CD4+ T cells and cytokines were histologically identified by immunofluorescence staining.
  
  
  RESULTS
  Corneal graft survival was prolonged by intraperitoneal injections in S1P1 alone (mean survival time MST, 35.3 ± 5.6 days), S1P1 combined with rapamycin (MST, 38.7 ± 6.5 days) or S1P1 and cyclosporine A (MST, 32.7 ± 4.8 days) compared with the controls (MST, 14.6 ± 0.2 days; n = 5, p < 0.01). S1P1 alone increased CD4+ T (p < 0.01) and Treg cells (p < 0.01; n = 5) in the cervical and mesenteric lymph nodes compared with the controls and S1P1 + rapamycin (p < 0.05; n = 5). TGF-β1 and IL-10 mRNA transcriptions in corneal grafts following S1P1+ rapamycin increased (both p < 0.01; n = 3), and TGF-β1 and IL-10 in the serum level following S1P1 alone increased (both p < 0.01; n = 3). These results paralleled the findings obtained from immunofluorescence.
  
  
  CONCLUSIONS
  S1P1 has significant effect in corneal allograft rejection inhibition. The combined treatment of S1P1 and rapamycin results in synergistic effect.
authors.affiliation: Department of Ophthalmology, the First Affiliated Hospital of the Chinese PLA General Hospital, Beijing 100038, ChinaDepartment of Ophthalmology, Chinese PLA General Hospital, Beijing 100853, ChinaDepartment of Ophthalmology, Chinese PLA Air force General Hospital, Beijing 100038, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhu
authors.forename: Yong
authors.initials: Y
authors.lastname: Liu
authors.forename: Yuli
authors.initials: Y
authors.lastname: Pi
authors.forename: Liang
authors.initials: L
authors.lastname: Jia
authors.forename: Liqiang
authors.initials: L
authors.lastname: Wang
authors.forename: Yifei
authors.initials: Y
authors.lastname: Huang
mesh_terms: D064591:Allografts; D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000502:physiology; D016039:Corneal Transplantation; D016572:Cyclosporine / Q000627:therapeutic use; D016207:Cytokines / Q000097:blood / Q000235:genetics; D003907:Dexamethasone / Q000627:therapeutic use; D004359:Drug Therapy, Combination; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D006084:Graft Rejection / Q000097:blood / Q000517:prevention & control*; D006085:Graft Survival / Q000187:drug effects; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D007274:Injections, Intraperitoneal; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D012333:RNA, Messenger / Q000235:genetics; D049349:Receptors, Lysosphingolipid / Q000627:therapeutic use*; D020123:Sirolimus / Q000627:therapeutic use; D050378:T-Lymphocytes, Regulatory / Q000502:physiology
chemical_list: D016207:Cytokines; D007166:Immunosuppressive Agents; D012333:RNA, Messenger; D049349:Receptors, Lysosphingolipid; D003907:Dexamethasone; D016572:Cyclosporine; D020123:Sirolimus
keywords: FTY720; Sphingosine 1-phosphate receptor 1; corneal transplantation; receptor modulators; rejection