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

BARBERO, ANGELA MARÍA; HERNÁNDEZ DEL PINO, R; PALMA, S; ROMANO, L; MENITE, N; FEDERICO FUENTES; BARRIONUEVO, PAULA; PASQUINELLI, VIRGINIA

Mar del Plata

Congreso; Reunión conjunta SAIC SAI&FAIC SAFIS 2022. LXVII reunión anual de la sociedad argentina de investigación clínica (SAIC). LXX reunión anual de la sociedad argentina de inmunología (SAI) y 3er congreso franco-argentino de inmunología (FAIC). Reunión anual 2; 2022

Macrophages (MΦ) constitute the primary barrier against pathogens,engulfing and digesting the microorganisms and thus, protectingthe host. In recent years, strong evidence indicates the roles ofthat platelets (P) in the immune response, including the interactionwith MΦ and the modulation of their inflammatory functions. Clostridioidesdifficile infection (CDI) is considered one of the most commonhealthcare-associated gastrointestinal infections related to antibiotictherapy. Many aspects of the immune response against C. difficilehave not been addressed yet. Here we explore the interplay betweenMΦ and P in the endocytosis of C. difficile. Peripheral blood, monocyte-derived MΦ and P from healthy donors were cultured in thepresence or absence of C. difficile (NAP1/BI/027 strain) inactivatedby heat treatment (CDH) or with FITC-coupled CDH. Our resultsshowed that human macrophages internalize CDH as measuredby flow cytometry and confocal microscopy. By using inhibitors ofdifferent endocytic pathways we found that CDH uptake occurs viamacropinocytosis. When macropinocytosis was blocked using amiloride,the internalization of CDH was reduced by more than 70%(p