Glucocorticoid and Fas ligand induced mucosal lymphocyte apoptosis after burn injury.
BACKGROUND
The purpose of this study was to examine the effects of a steam burn injury on apoptosis in gut-associated lymphoid tissue and to determine whether endogenous glucocorticoid and Fas ligand signaling were involved in this process.


METHODS
Histologic analysis, in situ deoxynucleotidyl transferase dUTP nick-end labeling staining and annexin V and 7-amino-actinomycin-D flow cytometry of lymphocyte populations were evaluated in intraepithelial lymphocytes and Peyer's patch. Additional mice were pretreated with a glucocorticoid receptor antagonist (mifepristone) before the steam burn. Similarly, C3H/HeJ-FasL(gld) mice lacking functional Fas ligand were also studied.


RESULTS
Apoptosis was significantly increased in intraepithelial lymphocytes and Peyer's patch after the burn injury. Mifepristone pretreatment significantly reduced apoptosis in both T- and B-cell populations in intraepithelial lymphocytes after the burn injury. In contrast, the increased apoptosis seen in B-cells from Peyer's patch was not seen in C3H/HeJFasL(gld) mice, whereas the increased apoptosis in CD8+ T-cells was unaffected.


CONCLUSIONS
Both corticosteroids and FasL contribute to the apoptosis in gut-associated lymphoid tissues early after burn injury.
Fukuzuka
K
K
Department of Surgery, University of Florida College of Medicine, Gainesville 32610-0286, USA.
Edwards
C K
CK
Clare-Salzer
M
M
Copeland
E M
EM
Moldawer
L L
LL
Mozingo
D W
DW
D000704:Analysis of Variance; D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000276:immunology*; D001402:B-Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D002056:Burns / Q000276:immunology* / Q000473:pathology; D004195:Disease Models, Animal; D053222:Fas Ligand Protein; D005260:Female; D005938:Glucocorticoids / Q000378:metabolism* / Q000494:pharmacology; D007413:Intestinal Mucosa / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D008221:Lymphoid Tissue / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000378:metabolism*; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D015735:Mifepristone / Q000494:pharmacology; D010581:Peyer's Patches / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism
D053222:Fas Ligand Protein; C505658:Fasl protein, mouse; D005938:Glucocorticoids; D008562:Membrane Glycoproteins; D015735:Mifepristone