EFFECTS OF ORALLY ADMINISTRED LIPOTEICHOIC ACID PURIFIED FROM LACTOBACILLUS RHAMNOSUS GG ON DENDRITIC CELLS IN MOUSE LAMINA PROPRIA, MESENTERIC LYMPH NODES AND PEYER PATCHES.

FRIEDRICH, A; SOUZA NETO, F; CAMPO, V; LEONI, J; GONZÁLEZ MAGLIO, D; PAZ, M

Congreso; IV LASID Meeting; LXIII Argentinean Immunology Society Meeting; II French-Argentinean Immunology Meeting; 2015

In previous work our laboratory has proven orallyadministered lipoteichoic acid (LTA) isolated from probiotic Lactobacillusrhamnosus GG to have anti-tumoral effect against UV-induced skin tumors. We hypothesizethat dendritic cells (DCs) play a major role in this effect. Recently we showedthat LTA can maturate bone marrow derived DCs increasing CD80/CD86 and CD40 expressionin vitro. The aim of thepresent study is to evaluate the amount and phenotype of DCs in mouse laminapropria (LP), mesenteric lymph nodes (MLN) and Peyers? Patches (PP) after LTAoral administration.Adult Balb/cmice were administered with 8 doses of 100 µg/ml LTA or PBS every other day andeuthanized 24 hs after the last administration. Cells from LP, MLN and PP wereobtained and stained with anti-CD11c, MHCII, CD40, CD86 antibodies as well aswith 7AAD probe. The resultsobtained show a non-significant decrease in treated animals compared withcontrols in the percentage of viable CD11c+MHCIIlow (1.86±0.4% vs. 2.76±0.56%),CD11c+MHCIImid (0.91±0.37% vs. 1.30±0.13%) and CD11c+MHCIIhigh (0.45±0.19% vs.0.96±0.52%) cells in LP. There was a possitive correlation between MHCIIexpression and the mean fluorescence intensity (MFI) of both CD40 and CD86 inLP. On the other hand, we found a non-significant increase CD11c+MHCIIhigh cellsin PP (2.13±1.13% vs 1.62±0.78%) and MLN (3.37±1.37% vs. 2.45±0.89%). Our resultscould be explained by the effects of LTA on LP DCs and subsequent migration ofthese cells to PP and MLN. This could be part of the mechanisms involved in theanti-tumoral effect of LTA.