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

CAMPO, VALERIA; CELA, ELIANA; FRIEDRICH ADRIAN; LEONI, JULIANA; GONZÁLEZ MAGLIO, DANIEL

Pisa

Congreso; XVII Congeso de la Sociedad Europea de Fotobiologia; 2017

Sociedad Europea de Fotobiologia

Cutaneous exposure to UV radiation (UVr) promotes well-known detrimental effects on health,such as the development of skin cancer and specific immunosuppression. However, the impactof UV-induced immunosuppression on human vaccination has been poorly studied.Previously, we have reported that a single high UV dose (shUVd - 400 mJ/cm2) promotes skininflammation while it decreases CHS reaction. In contrast, repetitive low UV doses (rlUVd - 4consecutive days, 20 mJ/cm2) do not induce inflammation but increase CHS. The aim of thepresent work was to study the effect of cutaneous exposure to shUVd and rlUVd on theeffectiveness of BCG and pneumococcal vaccines.C57BL/6 and Balb/c mice were immunized 24h after irradiation, with intradermal BCG orintramuscular Pneumovax23. Non-irradiated vaccinated mice and non-vaccinated mice wereused as controls. DTH reactions were evaluated in BCG vaccinated mice 4 weeks afterimmunization, while specific IgG and IgM antibodies were evaluated weekly after vaccination,by ELISA.All BCG vaccinated mice presented positive DTH reactions in both strains, but only in C57BL/6mice a significant increase was observed in shUVd exposed animals vs. rlUVd and non-irradiated mice (1.52 vs 1.04 or 1.09 mm). No specific antibody production was observed inBalb/c mice, while there was a non-significant increase in specific IgG in C57BL/6 mice (1.1 vs0.3 OD492 units).Regarding Pneumovax23 immunization, specific IgM and IgG were significantly increased in allvaccinated groups of both mice strains one week after the challenge (0.917 vs 0.221 OD492units). Specific IgM was detected up to 5 weeks after immunization in C57BL/6 mice, but inBalb/c mice only until week 2. There were no significant differences in the response ofirradiated groups. On the contrary, specific IgG significantly decreased in shUVd-exposedC57BL/6 mice compared with rlUVd ones (0.98 vs 0.51 OD492 units).These results suggest that UVr is able to modulate immune responses to vaccines dependingon its nature as well as on the mice strain used. BCG vaccination, effective in both mice strains,showed a predominant cellular immune response without production of specific antibodies(expected for intracellular bacteria). The immune response to this vaccine was not affected byUV irradiation (shUVd or rlUVd). Pneumovax23 vaccination, also effective in both mice strains,induced specific IgG and IgM antibodies, which were not affected in Balb/c irradiated mice butwere significantly decreased in shUVd C57BL6 mice.