Exposure to Low Doses of Solar‐Simulated Radiation Induces an Increase in the Myeloid Subtype of Blood Dendritic Cells

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 solarsimulated 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:. 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 ¼ 0.006 and P ¼ 0.018, respectively). A particularly distinct increase was observed in the percentage of the MDC1 after 2 and 30 days (P ¼ 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 ¼ 0.031). A significant increase in PDC was found after 2 days of irradiation (P ¼ 0.0006). Exposure to SSR induced an increase in the percentage of BDC in healthy human individuals, especially apparent in the MDC1 subtype.

Distribution and clinical significance of blood dendritic cells in children with juvenile idiopathic arthritis

“…As was previously found, these subpopulations strictly corresponded with mDC characterised by BDCA-1+/CD11c+/HLA-DR+ immunophenotype for mDC1 and BDCA-3+/CD32−/CD64−/HLA-DR+ for mDC2 subtype 23. The third subpopulation, pDC, was discriminated based on BDCA-2+/CD123+/HLA-DR+ immunophenotype (fig 1C).…”

The Effect of Chronic Ultraviolet Radiation on the Human Immune System†

“…Narbutt et al. (47) reported that whole‐body suberythemal SSR of volunteers daily for up to 30 days induced an increase in the percentage of DCs within the peripheral blood mononuclear population. In particular there was an increase in DCs characterized as myeloid subtype 1.…”

Ação da pentoxifilina nos dendrócitos dérmicos FXIIIa de placas de psoríase

“…Narbut e cols. 28 encontraram aumento de célu-las dendríticas subtipos mielóide e plasmocitóide no sangue periférico após exposição a baixas doses de radiação solar símile (SRR) que poderia refletir o elevado recrutamento de DC na pele como parte da resposta ao UVR. É bem conhecido o fato de que muitas LCs presentes na epiderme migram para os linfono- dos após a UVR, e, ao mesmo tempo, a mobilização de precursores LC, dos DDs mielóides é observada.…”

“…Haveria, assim, um provável recrutamento intenso de células dendríticas da pele, como ocorre com a exposição à radiação ultravioleta. 28,29 Sabe-se também que substâncias inibidoras dos mediadores dos mastócitos não melhoram a placa psoriásica. 27 O aumento da população de DDs FXIIIa+ após o tratamento com PTX também poderia ser explicado pela diminuição da migração dessas células da derme para os órgãos linfóides secundários.…”