Short-term fever-range hyperthermia modulates human neutrophil responses

KEITELMAN, IRENE; IULA, LEONARDO; SABBIONE, FLORENCIA; JANCIC, CAROLINA; TREVANI, ANALIA

Buenos Aires

Congreso; Congreso Internacional SAI-FAIC; 2015

Sociedad Franco Argentina de Inmunología

Abstract: Background:Fever is a physiological response to infection and injury that takes place as a consequence of the temporary resetting of the body?s thermostatic set point. It?s accepted that it confer cytoprotection and have beneficial effects, but the mechanisms and the outcomes of fever are poorly understood. During the course of fever or local inflammation, neutrophils become exposed to temperatures between 38°C-42°C. Here we investigated if fever?range hyperthermia (39.5°C) exerts immunomodulatory effects on human neutrophils. Methods:Neutrophils isolated from healthy donors were incubated in the presence or absence of stimuli at 37°C or 39.5°C for 1h, and then cultured different times at 37°C. Then, the impact otemperature on different neutrophil functions was determined. Neutrophil mediated phagocytosis of FITC-conjugated heat-inactivated S.aureus was evaluated by flow cytometry, the secretion of proinflammatory cytokines (IL-1β and IL-8) was determined by ELISA, the ability to undergo NETosis was assessed by confocal microscopy and by measuring the release of DNA by fluorometry. Results:Hyperthermia significantly inhibited bacterial phagocytosis (p