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; REUNIÓN CONJUNTA DE SOCIEDADES DE BIOCIENCIAS; 2017

SOCIEDADES DE BIOCIENCIAS

Myeloid-derived suppressor cells (MDSCs) are a heterogeneouspopulation of immature and immunesupressive myeloid cells. Thesecells are characterized by expression of CD11b and Gr-1, and aredivided into two major subsets: granulocytic and monocytic MDSCs.Yersinia enterocolitica (Ye) are Gram-negative bacteria that causefood-borne acute or chronic gastrointestinal diseases. The role ofMDSCs in Ye infection has not been determined. The purpose wasto elucidate whether oral Ye infection induces the expansion of MDSCsand 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 lymphnodes (MLN), Peyer´s patches (PP) and spleen was analyzed. Suppressiveactivity was determined by MTT assay. Moreover, the roleof Ye outer protein P (YopP) or H (YopH) in MDSC expansion wasexplored using for infection Ye deficient in YopP or YopH, respectively.We found that Ye-infected mice presented an increase in thefrequencies of CD11b+Gr-1+ cells in PP, MLN and spleen on days 5p.i, compared to uninfected mice (p