INVESTIGADORES
GONZALEZ MAGLIO Daniel Horacio
congresos y reuniones científicas
Título:
Mice exposure to repetitive low UV doses differentially affects the immune system compared to elevated doses, enhancing specific antibody production.
Autor/es:
CELA, E.M.; PAZ, M.L.; FRIEDRICH, A.D.; LEONI, J.; GONZALEZ MAGLIO, D.H.
Lugar:
Edimburgo
Reunión:
Congreso; International Investigative Dermatology 2013; 2013
Institución organizadora:
American, European and Japanese Societies for Investigative Dermatology (SID, ESID, JSID).
Resumen:
Skin UV exposure induces both a systemic
immunesuppression and Vitamin D synthesis, which in turns promotes
transcription of immune mediators such as antimicrobial peptides and TLR-2.
SKH-1 hairless mice were irradiated with repetitive low UV doses (4 times of 20
mJ/cm2 -simulating daily exposure-) or a single high dose (400 mJ/cm2
simulating harmful exposure-) to compare their cellular as well as immune
effects, 1 and 8 days post-UV.
Both UV doses led to an increase in epidermal
thickness& (H&E), but only 4x20 activated mitochondrial
function# (DiOC6+ cells) while 1x400 produced
the opposite effect&, with the
consequent increment in superoxide production# (MitoSOX+
cells), by flow cytometry. Inflammatory mediators (IL-6 and TNF-α) were
increased only in 1x400, in dermis& and epidermis& extracts, assayed by ELISA. Epidermal T
cell percentage (CD3+ cells) was markedly decreased in
1x400# (flow cytometry); accordingly, epidermal transcription of
CXCL-12 was also decreased&, but in all mice groups&
(RT-PCR). Both UV doses induced an increment in VEGF transcription, in dermis
and epidermis#, but none of them had effects on the transcription of
TLR-2 and TLR-4, in both tissues (RT-PCR), or in the 25-OH-Vit D serum levels
(RIA). Finally, a tetanus toxoid (TT) challenge was performed for each UV-dose
1 or 8d after irradiation and serum antibodies were titrated. Anti-TT specific
total IgG# and IgG3# were increased 1d
post-4x20 (3.4 and 3.5 fold), while anti-TT IgG1& and
IgG2b* were decreased 1d post-1x400 (3.0 and 4.6 fold).
Immunizations performed 8d after-UV did not have effects on specific antibodies
titre, in neither group. All differences are expressed vs non-irradiated
control mice: *p<0.05, #p<0.01, &p<0.001.
Simulated daily UV-exposure shares some of the
negative effects produced by a harmful high-dose, in contrast it does not
induce strong inflammation and it is also unexpectedly capable of increasing
the specific humoral immune response.