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Time–course study of different innate immune mediators produced by UV‐irradiated skin: comparative effects of short and daily versus a single harmful UV exposure
Author(s) -
Cela Eliana M.,
Friedrich Adrian,
Paz Mariela L.,
Vanzulli Silvia I.,
Leoni Juliana,
González Maglio Daniel H.
Publication year - 2015
Publication title -
immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.297
H-Index - 133
eISSN - 1365-2567
pISSN - 0019-2805
DOI - 10.1111/imm.12427
Subject(s) - hairless , chemokine , innate immune system , immune system , immunology , inflammation , biology , psoriasis , population , epithelium , antimicrobial peptides , lymphatic system , pathology , antimicrobial , medicine , microbiology and biotechnology , biochemistry , environmental health
Summary The modulatory effects of solar UV radiation on the immune system have been widely studied. As the skin is the main target of UV radiation, our purpose was to compare the impact on skin innate immunity of two contrasting ways to be exposed to sunlight. Hairless mice were UV irradiated with a single high UV dose simulating a harmful exposure, or with repetitive low UV doses simulating short occasional daily exposures. Skin samples were taken at different times after UV irradiation to evaluate skin histology, inflammatory cell recruitment, epidermal T‐cell population and the mitochondrial function of epidermal cells. The transcriptional profiles of pro‐inflammatory cytokines, chemokines, antimicrobial peptides and Toll‐like receptors were evaluated by RT ‐ PCR and ELISA in tissue homogenates. Finally, a lymphangiography was performed to assess modification in the lymphatic vessel system. A single high UV dose produces a deep inflammatory state characterized by the production of pro‐inflammatory cytokines and chemokines that, in turn, induces the recruitment of neutrophils and macrophages into the irradiated area. On the other hand, repetitive low UV doses drive the skin to a photo‐induced alert state in which there is no sign of inflammation, but the epithelium undergoes changes in thickness, the lymphatic circulation increases, and the transcription of antimicrobial peptides is induced.