Expression of HLA-G in human cornea, an immune-privileged tissue.
Human leukocyte antigen (HLA)-G retains the capacity to modulate immune responses, favoring the establishment of tolerance in solid-tissue allotransplants. To better understand the mechanisms that promote corneal allograft survival, we investigated whether HLA-G was an immunoregulatory factor involved in corneal immunology. We therefore sought HLA-G expression in corneal tissues. Corneal transplantation consists in replacing the center of a diseased cornea with normal corneal tissue. Two corneal parts are not used in such surgery: diseased central corneal tissue and peripheral normal cornea. For this study, we used healthy corneas obtained from deceased donors and diseased corneas obtained from patients with pseudophakic bullous keratopathy or keratoconus who had undergone corneal transplantation. Immunohistochemical analysis carried out on the cryopreserved corneas showed a positive immunohistochemical staining with anti-HLA-G, anti-HLA-A, -B, and -C, and anti-HLA class I monoclonal antibodies. Staining was obtained for keratocytes, epithelial cells, and endothelial cells from both healthy and pathologic human corneas, revealing the presence of HLA class I proteins, including HLA-G. HLA-G transcripts were detected in normal cornea by reverse transcriptase-polymerase chain reaction with a classical pattern of alternative splicing. The detection of HLA-G protein in adult corneas leads to the conclusion that this protein may contribute to the maintenance of the privileged immune status of cornea.
Le Discorde
Magali
M
Service de Recherches en Hémato-Immunologie, CEA-DSV-DRM, Institut d'Hématologie, Hôpital Saint-Louis, Paris, France. teyssier@dsvidf.cea.fr
Moreau
Philippe
P
Sabatier
Patrick
P
Legeais
Jean-Marc
JM
Carosella
Edgardo D
ED
D000328:Adult; D003315:Cornea / Q000166:cytology / Q000276:immunology*; D003316:Corneal Diseases / Q000276:immunology*; D016039:Corneal Transplantation; D005455:Fluorescent Antibody Technique; D006680:HLA Antigens / Q000032:analysis* / Q000235:genetics / Q000276:immunology; D015234:HLA-A Antigens / Q000032:analysis; D015235:HLA-B Antigens / Q000276:immunology; D015236:HLA-C Antigens / Q000032:analysis; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I / Q000032:analysis* / Q000235:genetics / Q000276:immunology; D006801:Humans; D007150:Immunohistochemistry; D007640:Keratoconus / Q000276:immunology*; D019591:Pseudophakia / Q000276:immunology*; D012313:RNA / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction
D006680:HLA Antigens; D015234:HLA-A Antigens; D015235:HLA-B Antigens; D015236:HLA-C Antigens; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I; D012313:RNA