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.
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-FasLgld
mice lacking functional Fas ligand were also studied.
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/HeJ-FasLgld
mice, whereas the increased apoptosis
T-cells was unaffected.
Both corticosteroids and FasL contribute to the apoptosis
in gut-associated lymphoid tissues early after burn injury.