Role of natural killer dendritic cells in host resistance against pseudomonas aeruginosa infection after thermal injury in mice

The contributions of dendritic cells (DCs) and natural killer dendritic cells (NKDCs) on host antibacterial innate immunities have been described. We have previously reported that mice with partial-thickness burn injuries (PT-burn mice) are resistant to burn wound infections, whereas mice with full-thickness burn injuries (FT-burn mice) are susceptible. In this study, the effect of burn stress on the appearance and properties of DCs and NKDCs was investigated in two different murine models of thermal injury. Dendritic cells isolated from PT-burn mice produced CCL3 and IL-12, whereas these soluble factors were not produced by DCs from FT-burn mice. As compared with unburned mouse controls, a large number of NKDCs were isolated from the DC preparations from PT-burn mice, whereas fewer NKDCs were detected in the DC preparations from FT-burn mice. Nonobese diabetic severe combined immunodeficiency mice inoculated with NKDCs were shown to be resistant against a lethal s.c. Pseudomonas aeruginosa infection. These results strongly suggest that NKDCs influenced by partial-thickness burn injury play a role on the resistance of PT-burn mice to P. aeruginosa s.c. infection.