Yersinia enterocolítica oral infection induces expansión of cells with phenotype of myeloid-derived supresor cells in intestinal mucosa and spleen.

LEPORATI, MARIANELA; ELIÇABE, JAVIER; DI GENARO, SILVIA

Congreso; LXIV Reunión anual de la Sociedad Argentina de Inmunología; 2016

Background: Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of immature and immunesupressive myeloid cells. These cells are characterized by coexpression of CD11b and Gr-1, and are divided into two major subsets, granulocytic (CD11b+Ly6G+Ly6Clow) and monocytic (CD11b+Ly6G−Ly6Chi) MDSCs. Yersinia enterocolitica (Ye) are Gram-negative bacteria that cause food-borne acute or chronic gastrointestinal and systemic diseases. The role of MDSCs in Ye infection has not been determined. Objective: The purpose was to elucidate whether oral Ye infection induces the expansion of MDSCs and to define the role of these cells in the infection. Methods: First, C57BL/6 mice were orally infected with Ye WAP-314 serotype O:8. On days 5 and 10 post-infection (p.i), cell infiltration in mesenteric lymph nodes (MLN), Peyer´s patches (PP) and spleen was analyzed. Moreover, total and specific IgA responses in feces, and IL-6 levels in sera were measured. Results: We observed that Ye-infected mice presented a dramatic increases in the frequencies as well as in the absolute numbers of CD11b+GR-1+ cells in PP, MLN and spleen on days 5 and 10 p.i (p