High salt induced a delayed activation of human neutrophils

MAZZITELLI I; BLEICHMAR L; MELUCCI C; PEREYRA GERBER P; TOSCANINI A; CUESTAS M; ERRA DÍAZ, FERNANDO; GEFFNER J

Frontiers in Immunology

Frontiers

Año: 2022

1664-3224

High salt (NaCl) concentrations are found in a number of tissues under physiological andpathological conditions. Here, we analyzed the effects induced by high salt on the functionof human neutrophils. The culture of neutrophils in medium supplemented with high salt(50 mM NaCl) for short periods (30-120 min) inhibited the ability of conventional agoniststo induce the production of IL-8 and the activation of respiratory burst. By contrast,exposure to high salt for longer periods (6-18 h) resulted in the activation of neutrophilsrevealed by the production of high levels of IL-8, the activation of the respiratory burst, anda marked synergistic effect on the production of TNF-a induced by LPS. Increasingosmolarity of the culture medium by the addition of sorbitol or mannitol (100 mM) was Q10shown to be completely unable to stimulate neutrophil responses, suggesting that highsodium but not an increased osmolarity mediates the activation on neutrophils responses.A similar biphasic effect was observed when the function of monocytes was analyzed.Short term exposure to high salt suppressed IL-8 and TNF-a production induced by LPSwhile culture for longer periods triggered the production of IL-8 but not TNF-a in theabsence of LPS stimulation. Contradictory results have been published regarding howhigh salt modulates neutrophil function. Our results suggest that the modulation ofneutrophil function by high salt is strongly dependent on the exposure time.