title: Growth inhibitory effect of bovine lactoferrin to Toxoplasma gondii tachyzoites in murine macrophages: tyrosine phosphorylation in murine macrophages induced by bovine lactoferrin.
abstract: Previous studies have shown that lactoferrin induces growth inhibitory effects in mouse macrophages against intracellular Toxoplasma gondii, and these effects were not mediated by the oxygen-dependent and inorganic nitrogen-dependent pathway. To clarify the mechanism of anti-Toxoplasma gondii activity induced by lactoferrin, we examined whether lactoferrin promoted the phosphorylation of tyrosine residues in macrophage proteins. In immunoblotting assays using anti-[phosphorylated tyrosine] monoclonal antibody, phosphorylation of tyrosine residues was detected in protein(s) of approximately 30 kDa in macrophages incubated with lactoferrin. Inhibition of the lactoferrin-induced tyrosine-phosphorylation by genistein led to loss of the lactoferrin-induced growth inhibitory effect against the parasites. These findings suggest that lactoferrin induces tyrosine-phosphorylation in macrophages, and the tyrosine-phosphorylation seems to be associated with the induction of the growth inhibitory activity exerted against intracellular Toxoplasma gondii.
authors.affiliation: Department of Veterinary Physiology, Obihiro University of Agriculture and Veterinary Medicine, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Tanaka
authors.forename: Y
authors.initials: Y
authors.lastname: Omata
authors.forename: T
authors.initials: T
authors.lastname: Isamida
authors.forename: A
authors.initials: A
authors.lastname: Saito
authors.forename: K
authors.initials: K
authors.lastname: Shimazaki
authors.forename: K
authors.initials: K
authors.lastname: Yamauchi
authors.forename: N
authors.initials: N
authors.lastname: Suzuki
mesh_terms: D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D005260:Female; D019833:Genistein / Q000494:pharmacology; D007781:Lactoferrin / Q000494:pharmacology*; D017737:Macrophages, Peritoneal / Q000187:drug effects / Q000469:parasitology* / Q000502:physiology*; D051379:Mice; D010766:Phosphorylation; D019000:Phosphotyrosine / Q000378:metabolism; D014122:Toxoplasma / Q000187:drug effects* / Q000254:growth & development
chemical_list: D019000:Phosphotyrosine; D019833:Genistein; D007781:Lactoferrin