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

CAMPO, VALERIA; FRIEDRICH ADRIAN; MANUELLI, PAULA; PAZ, MARIELA; LEONI, JULIANA; GONZÁLEZ MAGLIO, DANIEL

Congreso; LASID-FAIC-SAI; 2015

It is well known that ultraviolet radiation (UVr) leads to immunosuppression, inhibiting contact hypersensitivity (CHS) reactions. However, the way UVr modulates immune responses against microorganisms and vaccines has been poorly explored. Previously, we have found that a single high UV dose (shUVd - 400 mJ/cm2) promotes skin inflammation while it decreases CHS, in contrast to repetitive low UV doses (rlUVD - 4 consecutive days, 20 mJ/cm2) which does not induce inflammation and increases CHS.Our aim was to evaluate the effect of both types of irradiation on BCG vaccination effectiveness in vivo.SKH:1 hairless mice were irradiated and 24h later immunized with intradermal BCG (1x106 CFU). Non-irradiated mice and non-vaccinated mice were used as control. Four weeks after vaccination, delayed-type hipersensitivity (DTH) reactions were evaluated and mice were bled and sacrificed. Cell proliferation and cytokine production were determined in vitro stimulating spleen cells with 40 µg/ml of BCG lysate. DTH reaction and specific IgG antibodies were slightly, but not significantly, increased in shUVd exposed animals compared with rlUVd ones (1.6 vs 1.1 mm and 0.92 vs 0.67 units of OD492 nm). In vitro T cell proliferation had no differences between groups, but IL-4 production was increased in rlUVd exposed animals compared with shUVd ones (19.2 vs 6.3 pg/ml; p