title: Mast cells are crucial in the resistance against Toxoplasma gondii oral infection.
abstract: During oral infection, mucosal immunity assumes a predominant role. Here, we addressed the role of mast cells (MCs), which are mainly located in mucosa during oral infection with Toxoplasma gondii, using MC-deficient (W/W(v) ) mice. We show that in the absence of MCs the resistance of W/W(v) mice to oral infection was considerably reduced. W/W(v) mice uniformly succumbed within 15 days of infection after administration of cysts of the ME49 strain of T. gondii. The rapid lethality of T. gondii in W/W(v) mice correlated with a delayed Th1-cell response, since IFN-γ and IL-12 levels peaked in the later phase of the infection. In vitro, BM-derived MCs were able to recognize parasite lysate in a MyD88-dependent way, reaffirming the role of this TLR adapter in immune responses to T. gondii. The importance of MCs in vivo was confirmed when W/W(v) mice reconstituted with BM-derived MCs from control mice retrieved an early strong Th1-cell response and specially a significant IL-12 production. In conclusion, MCs play an important role for the development of a protective immune response during oral infection with T. gondii.
authors.affiliation: School of Medicine, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil; Department of Biochemistry and Immunology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil.
authors.forename: Aline
authors.initials: A
authors.lastname: Cruz
authors.forename: Érica Araújo
authors.initials: ÉA
authors.lastname: Mendes
authors.forename: Marcus Vinícius Melo
authors.initials: MV
authors.lastname: de Andrade
authors.forename: Vanuza Chagas
authors.initials: VC
authors.lastname: do Nascimento
authors.forename: Christiane T
authors.initials: CT
authors.lastname: Cartelle
authors.forename: Rosa M E
authors.initials: RM
authors.lastname: Arantes
authors.forename: José Renan da Cunha
authors.initials: JR
authors.lastname: Melo
authors.forename: Ricardo Tostes
authors.initials: RT
authors.lastname: Gazzinelli
authors.forename: Catherine
authors.initials: C
authors.lastname: Ropert
mesh_terms: D000818:Animals; D005455:Fluorescent Antibody Technique; D018928:Immunity, Mucosal / Q000276:immunology*; D008407:Mast Cells / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D018417:Th1 Cells / Q000276:immunology; D014122:Toxoplasma / Q000276:immunology; D014124:Toxoplasmosis, Animal / Q000276:immunology*
keywords: Mast cells; Mucosal immunity; Oral infection; Th1-cell response; Toxoplasma gondii