Amniotic membrane transplantation induces apoptosis in T lymphocytes in murine corneas with experimental herpetic stromal keratitis.
OBJECTIVE
To investigate the effect of human amniotic membrane transplantation (AMT) on T-cell immune response in murine corneas with herpetic stromal keratitis (HSK).


METHODS
Herpes simplex virus (HSV)-1-infected BALB/c mice with necrotizing HSK were treated with AMT. CD3(+) cell apoptosis was determined in treated corneas and in vitro by flow cytometric analysis using the annexin V/7-AAD system. The effect of interleukin (IL)-2, cyclosporine, rapamycin, or Fas on T-cell survival was measured. Activation phenotype was measured by (3)H-thymidine uptake and flow cytometry (CD25, CD69, major histocompatibility complex class II). Cytokine/chemokine secretion from amniotic membrane (AM)-treated corneas or draining lymph node cells was measured. The immune-modulating capacity of long-term AMT treatment and adoptive transfer of AM-treated splenocytes was tested.


RESULTS
After AMT, HSK and corneal inflammatory cell infiltration improved, and T-lymphocyte apoptosis occurred. T-cell apoptosis was also induced in vitro, independently of rIL-2, cyclosporine, rapamycin, or Fas. AMT-treated corneas and cultured lymphocytes had reduced IL-2, IL-10, IL-12, CRG-2, and CCL-2 content. Long-term AMT treatment decreased the proliferative response and type 1 helper T-cell cytokine level in draining lymph node cells. The improvement in HSK did not persist. Delayed-type hypersensitivity or HSV-1-specific cytotoxicity was not altered


CONCLUSIONS
The results suggest that murine HSK improves after AMT through reduced local T-helper cell immune responses by inducing apoptosis in T lymphocytes, independently of passive apoptosis or activation-induced cell death. AM also reduces local T-helper cytokine and chemokine levels but does not result in immune deviation. Immunologic memory against HSV-1 is not affected by AMT, and long-term protection or tolerance is not induced.
Bauer
Dirk
D
Department of Ophthalmology, Ophtha-Lab, St Franziskus Hospital, Muenster, Germany. dirk.bauer@uveitis-zentrum.de
Wasmuth
Susanne
S
Hennig
Maren
M
Baehler
Hanna
H
Steuhl
Klaus-Peter
KP
Heiligenhaus
Arnd
A
D019264:Adoptive Transfer; D000650:Amnion / Q000637:transplantation*; D000818:Animals; D017209:Apoptosis; D017252:CD3 Complex / Q000276:immunology; D018929:Cell Culture Techniques; D002470:Cell Survival; D018920:Coculture Techniques; D003319:Corneal Stroma / Q000276:immunology / Q000601:surgery*; D016572:Cyclosporine / Q000494:pharmacology; D016207:Cytokines / Q000378:metabolism; D003602:Cytotoxicity, Immunologic; D004195:Disease Models, Animal; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D018259:Herpesvirus 1, Human / Q000502:physiology; D006968:Hypersensitivity, Delayed / Q000276:immunology; D016849:Keratitis, Herpetic / Q000276:immunology / Q000601:surgery*; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D019463:Mice, Inbred MRL lpr; D018345:Mice, Knockout; D018613:Microscopy, Confocal; D020123:Sirolimus / Q000494:pharmacology; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000473:pathology*
D017252:CD3 Complex; D016207:Cytokines; D016572:Cyclosporine; D020123:Sirolimus