title: Galectin-3 plays a modulatory role in the life span and activation of murine neutrophils during early Toxoplasma gondii infection.
abstract: Galectins are beta-galactoside-binding lectins involved in several biological processes and galectin-3 (Gal-3) is related to modulation of immune and inflammatory responses. This study aimed to evaluate the role of Gal-3 in the life span and biological functions of murine neutrophils during in vitro infection by virulent Toxoplasma gondii RH strain. Inflammatory peritoneal neutrophils (Nphi) from C57BL/6 wild-type (WT) and Gal-3 knockout (KO) mice were cultured in the presence or absence of parasites and analyzed for phosphatidylserine (PS) exposure and cell death using Annexin-V and propidium iodide staining, and cell viability by MTT assay. Cell toxicities determined by lactate dehydrogenase (LDH), degranulation by lysozyme release, and cytokine production were measured in Nphi culture supernatants. Phorbol myristate acetate (PMA)- or zymosan-dependent reactive oxygen species (ROS) were measured in Nphi cultures. Our results demonstrated that Gal-3 is involved in the increase of the viable Nphi number and the decrease of PS exposure and cell death following T. gondii infection. We also observed that Gal-3 downmodulates T. gondii-induced Nphi toxicity as well as Nphi degranulation regardless of infection. Furthermore, Gal-3 expression by Nphi was associated with increased levels of IL-10 in the beginning and decreased levels of TNF-alpha later on, regardless of parasite infection, as well as with decreased levels of IL-6 and increased IL-12 levels, following early parasite infection. Our results also showed that Gal-3 suppresses PMA- but not zymosan-induced ROS generation in Nphi following T. gondii infection. In conclusion, Gal-3 plays an important modulatory role by interfering in Nphi life span and activation during early T. gondii infection.
authors.affiliation: Laboratory of Immunoparasitology, Institute of Biomedical Sciences, Universidade Federal de Uberlândia, Uberlândia, Brazil.
authors.forename: Celene M O S
authors.initials: CM
authors.lastname: Alves
authors.forename: Deise A O
authors.initials: DA
authors.lastname: Silva
authors.forename: Ana Elisa C S
authors.initials: AE
authors.lastname: Azzolini
authors.forename: Cleni M
authors.initials: CM
authors.lastname: Marzocchi-Machado
authors.forename: Julianne V
authors.initials: JV
authors.lastname: Carvalho
authors.forename: Ana Cláudia A M
authors.initials: AC
authors.lastname: Pajuaba
authors.forename: Yara Maria
authors.initials: YM
authors.lastname: Lucisano-Valim
authors.forename: Roger
authors.initials: R
authors.lastname: Chammas
authors.forename: Fu-Tong
authors.initials: FT
authors.lastname: Liu
authors.forename: Maria C
authors.initials: MC
authors.lastname: Roque-Barreira
authors.forename: José R
authors.initials: JR
authors.lastname: Mineo
mesh_terms: D000818:Animals; D015550:Cell Degranulation / Q000235:genetics / Q000276:immunology; D002478:Cells, Cultured; D016207:Cytokines / Q000096:biosynthesis / Q000276:immunology; D037502:Galectin 3 / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D005786:Gene Expression Regulation / Q000235:genetics / Q000276:immunology*; D051379:Mice; D018345:Mice, Knockout; D018375:Neutrophil Activation / Q000235:genetics / Q000276:immunology*; D009504:Neutrophils / Q000276:immunology* / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000276:immunology / Q000378:metabolism; D014122:Toxoplasma / Q000276:immunology* / Q000378:metabolism; D014123:Toxoplasmosis / Q000235:genetics / Q000276:immunology* / Q000378:metabolism
chemical_list: D016207:Cytokines; D037502:Galectin 3; C485095:Lgals3 protein, mouse; D017382:Reactive Oxygen Species