Evaluation of the effects of skin ultraviolet light exposure on vaccination effectiveness.

CAMPO, VALERIA E; CELA, ELIANA M; FRIEDRICH, ADRIAN D; LEONI, JULIANA; GONZALEZ MAGLIO, DANIEL H

Pisa

Congreso; 17th Congress of the European Society for Photobiology; 2017

European Society for Photobiology

Cutaneous exposure to UV radiation (UVr) promotes well-known detrimentaleffects on health, such as the development of skin cancer and specificimmunosuppression. However, the impact of UV-induced immunosuppression on humanvaccination has been poorly studied. Previously, we have reported that a single high UV dose (shUVd - 400mJ/cm2) promotes skininflammation while it decreases CHS reaction. In contrast, repetitive low UVdoses (rlUVd - 4 consecutive days, 20 mJ/cm2) do not induce inflammationbut increase CHS. The aim of the present work was to study the effect ofcutaneous exposure to shUVd and rlUVd on the effectiveness of BCG andpneumococcal vaccines. C57BL/6 and Balb/c mice were immunized 24h after irradiation, withintradermal BCG or intramuscular Pneumovax23. Non-irradiated vaccinated miceand non-vaccinated mice were used as controls. DTH reactions were evaluated inBCG vaccinated mice 4 weeks after immunization, while specific IgG and IgMantibodies were evaluated weekly after vaccination, by ELISA. All BCG vaccinated mice presented positive DTH reactions in bothstrains, but only in C57BL/6 mice a significant increase was observed in shUVdexposed animals vs. rlUVd and non-irradiated mice (1.52 vs 1.04 or 1.09 mm). Nospecific antibody production was observed in Balb/c mice, while there was anon-significant increase in specific IgG in C57BL/6 mice (1.1 vs 0.3 OD492 units). Regarding Pneumovax23 immunization, specific IgM and IgG weresignificantly increased in all vaccinated groups of both mice strains one weekafter the challenge (0.917 vs 0.221 OD492 units). Specific IgM was detected up to 5 weeksafter immunization in C57BL/6 mice, but in Balb/c mice only until week 2. Therewere no significant differences in the response of irradiated groups. On thecontrary, specific IgG significantly decreased in shUVd-exposed C57BL/6 micecompared with rlUVd ones (0.98 vs 0.51 OD492 units). These results suggest that UVr is able tomodulate immune responses to vaccines depending on its nature as well as on themice strain used. BCG vaccination, effective in both mice strains, showed apredominant cellular immune response without production of specific antibodies(expected for intracellular bacteria). The immune response to this vaccine wasnot affected by UV irradiation (shUVd or rlUVd). Pneumovax23 vaccination, alsoeffective in both mice strains, induced specific IgG and IgM antibodies, whichwere not affected in Balb/c irradiated mice but were significantly decreased inshUVd C57BL6 mice.