Roles of dendritic cells in mediating decreased delayed type hypersensitivity responses after trauma / 中国医学科学院学报

ABSTRACT

<p><b>OBJECTIVE</b>To study the effects of hemorrhage combined with closed fracture on delayed type hypersensitivity (DTH) responses in mice and to explore the relevant mechanisms.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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).</p><p><b>CONCLUSION</b>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.</p>