Rat corneal allograft survival prolonged by the superantigen staphylococcal enterotoxin B.
OBJECTIVE
The purpose of this study was to determine the optimal conditions for prolonging corneal allograft survival by inducing anergy with the superantigen staphylococcal enterotoxin B (SEB).


METHODS
A rat model of penetrating keratoplasty, whereby Fisher344 donor corneas are implanted into Lewis recipients, was used to evaluate the effects of SEB on inhibiting immune-mediated allograft rejection. To induce anergy, SEB was injected into the peribulbar space of Lewis rats. Furthermore, histopathology and immunofluorescent staining were used to examine the levels of infiltrating CD4(+) and CD8(+) T lymphocytes and NK1.1(+) lymphocytes.


RESULTS
By administering SEB, at doses of 90 or 120 micro g/kg 7 days before and after keratoplasty, we suppressed the episode of corneal graft rejection for a median of 12 and 30 days, respectively. In contrast, rejection was observed when 30 or 60 micro g/kg of SEB was administered. After SEB injections, lymphocyte infiltration into the corneal grafts was reduced, and the expression of NK1.1(+) lymphocytes was enhanced, suggesting that anergy may be occurring. Also, there were no differences in the number of infiltrating CD4(+) and CD8(+) T lymphocytes cells between the control group and groups injected with 30 and 120 micro g/kg SEB on postoperative days 10 and 30.


CONCLUSIONS
Inducing anergy with the superantigen SEB prolonged corneal graft survival in a rat model of penetrating keratoplasty. Therefore, these results support the possibility of prolonging corneal allograft survival in a clinical setting by preventing immune-mediated rejection through the administration of the superantigen SEB.
Pan
Zhiqiang
Z
Beijing Institute of Ophthalmology, Beijing TongRen Eye Center, Capital University of Medical Sciences, Beijing, China. ebank416@msn.com
Chen
Yu
Y
Zhang
Wenhua
W
Jie
Ying
Y
Li
Na
N
Wu
Yuying
Y
D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D017635:Clonal Anergy; D003315:Cornea / Q000187:drug effects* / Q000276:immunology / Q000473:pathology; D004768:Enterotoxins / Q000494:pharmacology*; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D006085:Graft Survival / Q000187:drug effects* / Q000276:immunology; D015948:Keratoplasty, Penetrating; D007694:Killer Cells, Natural / Q000276:immunology; D051381:Rats; D011916:Rats, Inbred F344; D011917:Rats, Inbred Lew; D013211:Staphylococcus aureus; D018089:Superantigens / Q000494:pharmacology*; D014184:Transplantation, Homologous
D004768:Enterotoxins; D018089:Superantigens; C031818:enterotoxin B, staphylococcal