MACROPINOCYTOSIS AND PLATELETS ARE INVOLVED IN CLOSTRIDIOIDES DIFFICILE UPTAKE BY HUMAN MACROPHAGES

BARBERO, ANGELA MARÍA; HERNÁNDEZ DEL PINO, RODRIGO EMANUEL; PALMA, SABINA; ROMANO, LUCÍA; MENITE, NATALIA; FUENTES, FEDERICO; BARRIONUEVO, PAULA; PASQUINELLI, VIRGINIA

Mar del Plata

Congreso; Reunión Anual de Sociedades de Biociencias 2022; 2022

SAIC-SAI-FAIC-SAFIS

Macrophages (MΦ) constitute the primary barrier against pathogens, engulfing and digesting the microorganisms and thus, protecting the host. In recent years, strong evidence indicates the roles of that platelets (P) in the immune response, including the interaction with MΦ and the modulation of their inflammatory functions. Clostridioides difficile infection (CDI) is considered one of the most common healthcare-associated gastrointestinal infections related to antibiotic therapy. Many aspects of the immune response against C. difficile have not been addressed yet. Here we explore the interplay between MΦ and P in the endocytosis of C. difficile. Peripheral blood, monocyte-derived MΦ and P from healthy donors were cultured in the presence or absence of C. difficile (NAP1/BI/027 strain) inactivated by heat treatment (CDH) or with FITC-coupled CDH. Our results showed that human macrophages internalize CDH as measured by flow cytometry and confocal microscopy. By using inhibitors of different endocytic pathways we found that CDH uptake occurs via macropinocytosis. When macropinocytosis was blocked using amiloride, the internalization of CDH was reduced by more than 70% (p