Exposure to low doses of solar-simulated radiation induces an increase in the myeloid subtype of blood dendritic cells.

Narbutt J, Skibinska M, Lesiak A, Wozniacka A, Sysa-Jedrzejowska A, Cebula B, Robak T, Smolewski P.

Scandinavian journal of immunology · 2004

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Abstract

Exposure to ultraviolet radiation causes alterations of cutaneous and systemic immunity. The aim of our study was to assess the influence of low doses of solar-simulated radiation (SSR) on the phenotypes of blood dendritic cells (BDC). Healthy volunteers (94) were irradiated with a dose of 1.2 SED (standard erythema dose) of SSR for 2, 10 or 30 consecutive days. Blood samples were taken before the first exposure and 24 h after final exposure. The three main subsets of BDC were distinguished by flow cytometry: BDCA-2(+)/CD123(+)/HLA-DR(+) (plasmacytoid, PDC) and two myeloid subtypes BDCA-1(+)/CD11c(+)/HLA-DR(+) (MDC1) and BDCA-3(+)/CD32(-)/HLA-DR(+) (MDC2). The percentage of total DC was elevated in all groups by the UV exposure and was significantly increased after 2 and 30 days of irradiation (P = 0.006 and P = 0.018, respectively). A particularly distinct increase was observed in the percentage of the MDC1 after 2 and 30 days (P = 0.022 and P < 0.0001, respectively). The MDC2 showed an increase after 10 days and a subsequent significant decrease after 30 days of irradiation (P = 0.031). A significant increase in PDC was found after 2 days of irradiation (P = 0.0006). Exposure to SSR induced an increase in the percentage of BDC in healthy human individuals, especially apparent in the MDC1 subtype.