[Roles of dendritic cells in mediating decreased delayed type hypersensitivity responses after trauma].
OBJECTIVE
To study the effects of hemorrhage combined with closed fracture on delayed type hypersensitivity (DTH) responses in mice and to explore the relevant mechanisms.


METHODS
DTH responses were induced with 2, 4-dinitro-1-fluorobenzene (DNFB) or fluorescein isothiocyanate (FITC) skin painting after injury, and single cell suspensions from pooled inguinal lymph nodes were analyzed by flow cytometry for FITC+ cells and dendritic cells (DC). The ability of cells from pooled inguinal lymph nodes was tested 24 hours after skin painting with DNFB in transferring sensitization for DTH to DNFB.


RESULTS
The DTH responses after injury decreased significantly compared with that of sham-injured mice (P<0.01). Flow cytometry showed that FITC+ cells, FITC+/CD11c+ cells, and FITC+/CD11c+ / major histocompatibility complex II+ cells were all significantly decreased after trauma (P<0.01). The ability of cells to transfer sensitization for DTH to DNFB also declined (P<0.01).


CONCLUSIONS
Hemorrhage combined with closed fracture decreases the DTH responses in mice, which may be attributed to the reduced antigen-presenting capacity of DC in the injured mice.
Wang
Zhen-ping
ZP
Department 1, Institute of Surgery Research, Daping Hospital, Third Military Medical University, State Key Laboratory of Trauma, Burns, and Combined Injury, Chongqing 400042, China.
Liang
Hua-ping
HP
D000818:Animals; D003713:Dendritic Cells / Q000276:immunology*; D005596:Fractures, Closed / Q000150:complications / Q000276:immunology*; D006470:Hemorrhage / Q000150:complications / Q000276:immunology*; D006968:Hypersensitivity, Delayed / Q000276:immunology*; D051379:Mice