MYELOID-DERIVED SUPPRESSOR CELLS EXPANDED IN INTESTINAL MUCOSA AND ESPLEEN AFTER ORAL INFECTION WITH YERSINIA ENTEROCOLITICA: ROLE OF VIRULENCE FACTORS

MARIANELA LEPORATI; ROBERTO DAVICINO; SILVIA DI GENARO; JAVIER ELIÇABE

Buenos Aires

Congreso; Reunion Conjunta de Sociedades Biomedicas; 2017

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of immature and immunesupressive myeloid cells. These cells are characterized by expression of CD11b and Gr-1, and are divided into two major subsets: granulocytic and monocytic MDSCs. Yersinia enterocolitica (Ye) are Gram-negative bacteria that cause food-borne acute or chronic gastrointestinal diseases. The role of MDSCs in Ye infection has not been determined. The purpose was to elucidate whether oral Ye infection induces the expansion of MDSCs and to define the role of these cells in this infection. Therefore, C57BL/6 mice were infected with Ye WAP-314 serotype O:8. On days 5 post-infection (p.i), cell infiltration in mesenteric lymph nodes (MLN), Peyer´s patches (PP) and spleen was analyzed. Suppressive activity was determined by MTT assay. Moreover, the role of Ye outer protein P (YopP) or H (YopH) in MDSC expansion was explored using for infection Ye deficient in YopP or YopH, respectively. We found that Ye-infected mice presented an increase in the frequencies of CD11b+Gr-1+ cells in PP, MLN and spleen on days 5 p.i, compared to uninfected mice (p