Pubblicazione scientifica

Non-Specific Antibodies Induce Lysosomal Activation in Atlantic Salmon Macrophages Infected by Piscirickettsia salmonis

FILONE TECNOLOGICO	TEMA
economia circolare e sostenibilità

RIASSUNTO

Piscirickettsia salmonis, an aggressive intracellular pathogen, is the etiological agent of salmonid rickettsial septicemia (SRS). This is a chronic multisystemic disease that generates high mortalities and large losses in Chilean salmon farming, threatening the sustainability of the salmon industry. Previous reports suggest that P. salmonis is able to survive and replicate in salmonid macrophages, inducing an anti-inflammatory environment and a limited lysosomal response that may be associated with host immune evasion mechanisms favoring bacterial survival. Current control and prophylaxis strategies against P. salmonis (based on the use of antibiotics and vaccines) have not had the expected success against infection. This makes it urgent to unravel the host-pathogen interaction to develop more effective therapeutic strategies. In this study, we evaluated the effect of treatment with IgM-beads on lysosomal activity in Atlantic salmon macrophage-enriched cell cultures infected with P. salmonis by analyzing the lysosomal pH and proteolytic ability through confocal microscopy. The impact of IgM-beads on cytotoxicity induced by P. salmonis in infected cells was evaluated by quantification of cell lysis through release of Lactate Dehydrogenase (LDH) activity. Bacterial load was determined by quantification of 16S rDNA copy number by qPCR, and counting of colony-forming units (CFU) present in the extracellular and intracellular environment. Our results suggest that stimulation with antibodies promotes lysosomal activity by lowering lysosomal pH and increasing the proteolytic activity within this organelle. Additionally, incubation with IgM-beads elicits a decrease in bacterial-induced cytotoxicity in infected Atlantic salmon macrophages and reduces the bacterial load. Overall, our results suggest that stimulation of cells infected by P. salmonis with IgM-beads reverses the modulation of the lysosomal activity induced by bacterial infection, promoting macrophage survival and bacterial elimination. This work represents a new important evidence to understand the bacterial evasion mechanisms established by P. salmonis and contribute to the development of new effective therapeutic strategies against SRS.

DATA

Data di pubblicazione: 12/11/2020

AUTORI

PEREZ-STUARDO DIEGO
ESPINOZA ALLISON
TAPIA SEBASTIAN
MORALES-REYES JONATHAN
BARRIENTOS CLAUDIO
VALLEJOS-VIDAL EVA
SANDINO ANA M
SPENCER EUGENIO
TORO-ASCUY DANIELA
RIVAS-PARDO J ANDRES
REYES-LOPEZ FELIPE E
REYES-CERPA SEBASTIAN

ENTE DI AFFERENZA

CTR GENOMICA Y BIOINFORMATICA FACULTAD DE CIENCIAS UNIV MAYOR SANTIAGO CHILE
CONSORCIO TECNOLOGICO DE SANIDAD ACUICOLA ICTIO BIOTECHNOLOGIES SA SANTIAGO CHILE
DEPT CELL BIOLOGY PHYSIOLOGY & IMMUNOLOGY UNIV AUTONOMA DE BARCELONA BELLATERRA SPAIN
CTR BIOTECNOLOGIA ACUICOLA FACULTAD DE QUIM Y BIOLOGIA UNIV SANTIAGO DE CHILE SANTIAGO CHILE
LAB DE VIROLOGIA INST CIENCIAS BIOMEDICAS FACULTAD DE CIENCIAS SALUD UNIV AUTONOMA DE CHILE SANTIAGO CHILE
ESCUELA DE BIOTECNOLOGIA FACULTAD DE CIENCIAS UNIV MAYOR SANTIAGO CHILE

RIVISTA

Frontiers in Immunology, 11, 544718

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