Polyphenol Administration Impairs T cells Proliferation by Imprinting a Distinct Dendritic Cell Maturational Profile

Intestinal immune cells are exposed to numerous factors able to imprint a specific maturational profile to intestinal resident Dendritic Cells (DCs). Those factors include nutritionally derived compounds whose effects are still to be completely characterized.

In the present study, we examined the effects of DCs exposure to Quercetin and Piperin Reconstituted Oil Bodies (ROBs-QP). In particular we studied the LPS induced maturation of DCs exposed or not to ROBs-QP.

ROBs-QP administration skews the DCs maturational profile towards an alternative impaired inflammatory response. By microarray analysis we compared LPS response of ROBs-QP Vs vehicle treated DCs. We obtained a decreased ratio between pro- Vs anti-inflammatory cytokines, an impaired chemokine receptor switch, a decreased ability to recruit T cells and present antigens. This profile is unique of the ROBs-QP exposed DCs.

Finally, by two-photon intravital microscopy and OT-II adoptive transfer we demonstrate that ROBs-QP administration reduces the number of stable immunological synapse and, consequently, antigen specific T cells divisions.

Our data demonstrate that polyphenols exposure can educate DCs towards a new anti-inflammatory molecular profile responsible for dampening the inflammatory response, thus paving the way for complementary nutritional approaches for the treatment of chronic inflammatory syndromes.