Clues to decipher the rhythm of intestinal immunity

BIBIANA ELIZABETH BARRIOS; IVANNA NOVOTNY NÚÑEZ; LISA MACCIO MARETTO; NICOLAS NAZAR; SILVIA GRACIELA CORREA

Buenos Aires

Congreso; LXIII Argentinean Immunology Society Meeting; 2015

argentinean Immunology Society

The circadian system orchestrates the temporal organization of many aspects of physiology, including immunity. In mammals, synchronization of the circadian clock is accomplished by light stimuli, temperature and food. The interface between environmental signs and the intestinal immune system is poorly known. As tolerance is crucial in the intestinal immunity we evaluated several parameters in epithelium, afferent lymphatics (AL), mesenteric lymph nodes (MLN) and lamina propria (LP) from undisturbed C57BL/6 mice to assess if the tolerogenic activity of the intestine changes across the circadian period. The release of IL-10 and MCP-1 in AL and LP fluctuated along the day. In MLN the clock gene Per2 oscillated between lower values at 6/18hs and higher expression at 12/24hs whereas Bmal1 transcripts declined from 6 to 24 hs. A stream of MHC-II+ cells reached MLN at 18hs preceded by higher cellularity at 12hs in AL. Supporting this migratory wave, CCL21 levels peaked in MLN at 18hs while decoy receptor D6 augmented at 12hs in AL. We also measured β-catenin expression and mucin (Muc2) content in AL cells to determine oscillations in tolerogenic signals. At the beginning of the dark period a significant increase of β-catenin occurred (p