OBJECTIVETo investigate the use of dendritic cells derived from mice bone marrow to evaluate the cutaneous allergic reaction induced by chemical sensitizers.

METHODSDendritic cells derived from mice bone marrow were cultured and administrated with 2, 4-dinitrochlorobenzene (DNCB), nickel sulfate (NiSO4), sodium dodecyl sulfate (SDS) and hexyl cinnamic aldehyde (HCA), respectively. Cell membrane molecule CD86 and extracellular IL-1 beta, IL-6 and IL-12 were detected after 0, 1, 6, 12, 24, 36, 48 hour's administration, respectively.

RESULTSCD86 expression reached the highest level after exposure to DNCB for 48 h, and increased by about 279% compared with the control (P < 0.05), while it was lower than that of control after administrated with NiSO4 and HCA for 1 h and 6 h, and SDS for 36 h, respectively (P < 0.05). Extracellular IL-1 beta increased greatly after exposure to NiSO4 just for 1 h, with the maximum at 48 h (298 pg/ml, P < 0.05), and after exposure to HCA for 6 h, with maximum at 48 h (84 pg/ml, P < 0.05). However, it didn't fluctuate significantly after administrated with DNCB and SDS respectively, compared with the control. Extracellular IL-6 increased significantly after exposure to NiSO4 for 1 h, with the maximum at 24 h (2152 pg/ml, P < 0.05). After exposure to HCA, extracellular IL-6 reached the maximum at 1 h (1403 pg/ml), and then it was decreased quickly, but still higher than the control (P < 0.05), while it didn't change significantly after treatment with DNCB and SDS, compared with the control (P > 0.05). Extracellular IL-12 was not detected out among all the groups.

CONCLUSIONChemical sensitizer DNCB could induce the high expression of CD86 on DC membrane, and NiSO4 and HCA could induce DC to release IL-1 beta and IL-6. However, the irritant SDS had no such effect.

Animals ; B7-2 Antigen ; metabolism ; Cells, Cultured ; Dendritic Cells ; drug effects ; immunology ; metabolism ; Dinitrochlorobenzene ; pharmacology ; Interleukin-12 ; metabolism ; Interleukin-1beta ; metabolism ; Interleukin-6 ; metabolism ; Mice ; Mice, Inbred C57BL ; Nickel ; pharmacology ; Sodium Dodecyl Sulfate ; pharmacology

Although nickel hypersensitivity is known as a delayed-type hypersensitivity mediated by nickel-specific T cells, it is greatly influenced by other immune cells. Here we show that splenic natural killer cells (NK cells) directly or indirectly respond to nickel by secretion of IFN-gamma. Using enzyme-linked immunosorbent spot (ELISPOT) assays, we found that nickel-reactive cells readily secreted IFN-gamma when splenocytes were cultured in the presence of varying concentrations of nickel sulfate (NiSO4) for 24 h. However, nickel-reactive IL-2- or IL- 4-secreting cells were infrequent during the 24-h culture with NiSO4. Immune responses to nickel were innate, not adaptive, in nature since the frequency of nickel-reactive IFN-gamma-secreting cells did not increase upon previous exposure to NiSO4 and recombination activating gene (RAG)-1-deficient mice contained nickel-reactive IFN-gamma-secreting cells. The involvement of NK cells in the innate response to NiSO4 was confirmed since we could observe a significant reduction of the frequency of nickel-reactive cells in NK cell-depleted mice. Furthermore, the number of IFN-gamma secreting cells was significantly reduced in the ELISPOT assays when NKG2D was blocked by anti-NKG2D antibody. These results suggest that there is an early and rapid innate immune response to nickel, which is mediated by NK cells and the NKG2D receptor. The significance of the innate response to nickel is that it may contribute to development of the late T cell-mediated delayed type hypersensitivity against nickel.
Animals ; Homeodomain Proteins/genetics/metabolism ; Humans ; Immunity, Innate/immunology ; Interferon-gamma/*secretion ; *Irritants/immunology/pharmacology ; *Killer Cells, Natural/drug effects/immunology/secretion ; Mice ; Mice, Inbred C57BL ; Mice, Knockout ; NK Cell Lectin-Like Receptor Subfamily K/genetics/metabolism ; *Nickel/immunology/pharmacology ; Spleen/*cytology/immunology