Identification of MHC class I H-2 Kb/Db-restricted immunogenic peptides derived from retinal proteins.
OBJECTIVE
To identify H-2 Kb/Db-binding immunogenic peptides derived from retinal proteins.


METHODS
Computer-based prediction was used to identify potentially H-2 Kb/Db-binding peptides derived from the interphotoreceptor retinol-binding protein (IRBP), soluble retinal antigen (S-antigen), recoverin, phosducin, and pigment epithelium-derived factor (PEDF). The affinity of the peptides was analyzed by their abilities to upregulate the expression of major histocompatibility complex (MHC) class I on TAP-deficient cells (RMA-S cells) with flow cytometry. C57BL/6 mice were immunized subcutaneously, with individual peptides in incomplete Freund's adjuvant (IFA). Eight days after immunization, splenocytes were isolated for cytotoxic T-lymphocyte (CTL) analysis. A 51chromium-release assay was used to detect specific CTL reactivity generated in the cultures. Eyes were enucleated for histopathological analysis on day 21 after immunization with IRBP or IRBP and the immunogenic peptides.


RESULTS
All the 21 predicted peptides were found to upregulate expression of H-2 Kb/Db on RMA-S cells. Five peptides, the two IRBP-derived peptides IRBP89-96 and IRBP(101-108), and the three PEDF-derived peptides, PEDF389-397, PEDF139-147, and PEDF272-279, induced specific CTL responses in vivo, whereas the remaining 16 peptides, including 5 IRBP-derived peptides, 5 S-antigen-derived peptides, 1 recoverin-derived peptide, 1 phosducin-derived peptide, and 4 PEDF-derived peptides, did not induce specific CTL reactivity. The immunogenic peptides alone did not induce inflammation in the eyes, but they could enhance severity of uveitis induced by IRBP.


CONCLUSIONS
Five of 21 H-2 Kb/Db-binding retinal protein-derived peptides were found to be immunogenic, suggesting that these peptides could function as autoantigenic epitopes in the development of inflammatory eye diseases, such as uveitis.
Wang
Mingjun
M
Laboratory of Cellular Immunology, Department of Medical Anatomy, The Panum Institute, Copenhagen, Denmark. wang@mai.ku.dk
Bai
Fang
F
Pries
Mette
M
Buus
Søren
S
Prause
Jan U
JU
Nissen
Mogens H
MH
D000818:Animals; D019393:Arrestin / Q000276:immunology; D001324:Autoantigens / Q000276:immunology; D003601:Cytotoxicity Tests, Immunologic; D000939:Epitopes / Q000276:immunology*; D005136:Eye Proteins / Q000276:immunology* / Q000633:toxicity; D005260:Female; D005434:Flow Cytometry; D020555:GTP-Binding Protein Regulators / Q000276:immunology; D005805:Genes, MHC Class I / Q000502:physiology; D006183:H-2 Antigens / Q000276:immunology*; D064532:Histocompatibility Antigen H-2D; D007114:Immunization; D051379:Mice; D008810:Mice, Inbred C57BL; D009414:Nerve Growth Factors / Q000276:immunology; D010446:Peptide Fragments / Q000276:immunology* / Q000633:toxicity; D010750:Phosphoproteins / Q000276:immunology; D051603:Recoverin / Q000276:immunology; D012160:Retina / Q000276:immunology*; D012177:Retinol-Binding Proteins / Q000276:immunology; D015843:Serpins / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D014605:Uveitis / Q000139:chemically induced / Q000276:immunology; D000099214:Retinol-Binding Proteins, Interstitial; D000099174:Pigment Epithelium-Derived Factor
D019393:Arrestin; D001324:Autoantigens; D000939:Epitopes; D005136:Eye Proteins; D020555:GTP-Binding Protein Regulators; D006183:H-2 Antigens; D064532:Histocompatibility Antigen H-2D; D009414:Nerve Growth Factors; D010446:Peptide Fragments; D010750:Phosphoproteins; D051603:Recoverin; D012177:Retinol-Binding Proteins; D015843:Serpins; D000099214:Retinol-Binding Proteins, Interstitial; D000099174:Pigment Epithelium-Derived Factor; C032876:H-2Kb protein, mouse; C065631:phosducin