title: Different impact of heat-inactivated and viable lactic acid bacteria of aquatic origin on turbot (Scophthalmus maximus L.) head-kidney leucocytes.
abstract: In aquaculture, several criteria should be considered to select an appropriate probiotic, including the aquatic origin and safety of the strain and its ability to modulate the host immune response. The properties and effects of probiotics are strain-specific and some factors such as viability, dose and duration of diet supplementation may regulate their immunomodulatory activities. In this study, we assessed the in vitro effect of eight heat-inactivated and viable lactic acid bacteria (LAB) of aquatic origin belonging to the genera Enterococcus, Lactobacillus, Lactococcus, Leuconostoc, Pediococcus and Weissella on the viability and innate immune response of turbot (Scophthalmus maximus L.) leucocytes. Head-kidney leucocytes were incubated with viable and heat-inactivated LAB at different concentrations. After incubation, the viability of leucocytes was evaluated using colorimetric assays (MTT and LDH) and flow cytometry (annexin V/propidium iodide). Heat-inactivated LAB showed no cytotoxic effect while viable LAB exerted variable influence on apoptosis of turbot phagocytes and lymphocytes. Leucocyte respiratory burst activity and phagocytosis were also differentially activated, as viable LAB stimulated leucocytes more efficiently than the heat-inactivated LAB. Our results suggest diverse strain-specific mechanisms of interaction between the evaluated LAB and turbot leucocytes. Furthermore, our work sets up in vitro systems to evaluate the effect of LAB as potential probiotics, which will be useful to develop efficient screening.
authors.affiliation: Grupo de Seguridad y Calidad de los Alimentos por Bacterias Lácticas, Bacteriocinas y Probióticos (Grupo SEGABALBP), Departamento de Nutrición, Bromatología y Tecnología de los Alimentos, Facultad de Veterinaria, Universidad Complutense de Madrid, 28040-Madrid, Spain.
authors.forename: Estefanía
authors.initials: E
authors.lastname: Muñoz-Atienza
authors.affiliation: Grupo de Seguridad y Calidad de los Alimentos por Bacterias Lácticas, Bacteriocinas y Probióticos (Grupo SEGABALBP), Departamento de Nutrición, Bromatología y Tecnología de los Alimentos, Facultad de Veterinaria, Universidad Complutense de Madrid, 28040-Madrid, Spain; Institute for Biotechnology and Bioengineering, Centre of Genomics and Biotechnology, University of Trás-os-Montes and Alto Douro, 5001-801-Vila Real, Portugal.
authors.forename: Carlos
authors.initials: C
authors.lastname: Araújo
authors.affiliation: Centro Oceanográfico de Vigo, Instituto Español de Oceanografía (IEO), 36390-Vigo, Pontevedra, Spain.
authors.forename: Nuria
authors.initials: N
authors.lastname: Lluch
authors.affiliation: Grupo de Seguridad y Calidad de los Alimentos por Bacterias Lácticas, Bacteriocinas y Probióticos (Grupo SEGABALBP), Departamento de Nutrición, Bromatología y Tecnología de los Alimentos, Facultad de Veterinaria, Universidad Complutense de Madrid, 28040-Madrid, Spain.
authors.forename: Pablo E
authors.initials: PE
authors.lastname: Hernández
authors.affiliation: Grupo de Seguridad y Calidad de los Alimentos por Bacterias Lácticas, Bacteriocinas y Probióticos (Grupo SEGABALBP), Departamento de Nutrición, Bromatología y Tecnología de los Alimentos, Facultad de Veterinaria, Universidad Complutense de Madrid, 28040-Madrid, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Herranz
authors.affiliation: Grupo de Seguridad y Calidad de los Alimentos por Bacterias Lácticas, Bacteriocinas y Probióticos (Grupo SEGABALBP), Departamento de Nutrición, Bromatología y Tecnología de los Alimentos, Facultad de Veterinaria, Universidad Complutense de Madrid, 28040-Madrid, Spain.
authors.forename: Luis M
authors.initials: LM
authors.lastname: Cintas
authors.affiliation: Centro Oceanográfico de Vigo, Instituto Español de Oceanografía (IEO), 36390-Vigo, Pontevedra, Spain. Electronic address: susana.magadan@jouy.inra.fr.
authors.forename: Susana
authors.initials: S
authors.lastname: Magadán
mesh_terms: D000818:Animals; D017209:Apoptosis; D002470:Cell Survival; D005412:Flatfishes / Q000276:immunology*; D060226:Head Kidney / Q000276:immunology*; D006358:Hot Temperature; D007113:Immunity, Innate; D007770:L-Lactate Dehydrogenase; D019344:Lactic Acid; D056546:Lactobacillales; D007962:Leukocytes / Q000276:immunology*; D010587:Phagocytosis; D019936:Probiotics; D016897:Respiratory Burst
chemical_list: D019344:Lactic Acid; D007770:L-Lactate Dehydrogenase
keywords: Apoptosis; Fish probiotics; In vitro immunomodulation; Lactic acid bacteria; Turbot head-kidney leucocytes