Increased number of dendritic cells in draining lymph nodes accompanies the generation of contact photosensitivity.
Draining lymph node cells isolated from mice 48 h after topical exposure to tetrachlorosalicylanilide (TCSA) + UVA radiation (TCSA + UVA) demonstrated a two-fivefold increase in the number of dendritic cells (DC) compared with control mice treated with vehicle + UVA. The increase in number of DC was both time and dose dependent, with the peak DC accumulation occurring at 48 h post application and at a TCSA dose of 1.0%. Photospecificity was evident in that mice irradiated prior to treatment with TCSA (UVA/TCSA) demonstrated no significant increase in DC accumulation. The accumulation of DC was followed by a significant increase in total lymph node cellularity. An in situ 3H-thymidine incorporation assay showed a significant increase in proliferative activity of cells isolated from the draining lymph nodes of mice treated with TCSA + UVA as compared to naive, vehicle, or UVA/TCSA-treated mice. Dendritic cells isolated from mice treated 24 h earlier with TCSA + UVA, but not those from naive mice or mice treated with UVA/TCSA, were capable of TCSA-specific antigen presentation. Responder lymphocytes from untreated mice or mice photosensitized with musk ambrette showed a much lower response to DC isolated from TCSA + UVA-treated mice, demonstrating the specificity of the reaction. DC-depleted lymph node cells were unable to stimulate this blastogenesis response. These results suggest that application and photoactivation of TCSA induces cellular and functional changes in the lymph node DC indicative of their involvement in the induction phase of a contact photoallergic reaction.
Gerberick
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Procter & Gamble Company, Miami Valley Laboratories, Cincinnati, Ohio 45239-8707.
Ryan
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CA
Fletcher
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Howard
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Robinson
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D000485:Allergens / Q000276:immunology*; D000818:Animals; D001666:Binding Sites, Antibody; D003429:Cross Reactions; D004391:Dust; D000939:Epitopes; D007123:Immunoelectrophoresis, Two-Dimensional; D007073:Immunoglobulin E / Q000276:immunology / Q000378:metabolism; D008925:Mites / Q000276:immunology*; D012532:Scabies / Q000276:immunology*; D013045:Species Specificity
D000485:Allergens; D004391:Dust; D000939:Epitopes; D007073:Immunoglobulin E