title: Exacerbation of Leishmania (Viannia) shawi infection in BALB/c mice after immunization with soluble antigen from amastigote forms.
abstract: The present study aimed to evaluate the effects of immunization with soluble amastigote (AmaAg) and promastigote (ProAg) antigens from Leishmania (Viannia) shawi on the course of infection in BALB/c mice. After immunization with AmaAg, the challenged group showed greater lesion size and parasite load in the skin and lymph nodes, associated with diminished interleukin (IL)-2, IL-4, IL-10, interferon (IFN)-γ and nitrate levels in the supernatant of lymph node cell cultures, together with increases in transforming growth factor (TGF)-β concentrations and humoral immune response. In contrast, immunization with ProAg led to smaller lesion size with reduced numbers of viable parasites in the skin. Protection was associated with increases in IL-12, IFN-γ, TGF-β and nitrates and decreases in IL-4 and IL-10 levels. Concerning humoral immune response, a significant reduction in anti-leishmania immunoglobulin G was verified in the ProAg-challenged group. Analysis of these results suggests that AmaAg induced a suppressive cellular immune response in mice, favouring the spread of infection, whereas ProAg induced partial protection associated with increased cellular immune response.
authors.affiliation: Departamento de Patologia, Universidade de São Paulo, Brasil.
authors.forename: Luiz Felipe Domingues
authors.initials: LF
authors.lastname: Passero
authors.forename: Maria Luiza Antunes
authors.initials: ML
authors.lastname: Da Costa Bordon
authors.forename: Ana Kely
authors.initials: AK
authors.lastname: De Carvalho
authors.forename: Luciano Moura
authors.initials: LM
authors.lastname: Martins
authors.forename: Carlos Eduardo Pereira
authors.initials: CE
authors.lastname: Corbett
authors.forename: Márcia Dalastra
authors.initials: MD
authors.lastname: Laurenti
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood / Q000276:immunology*; D000953:Antigens, Protozoan / Q000276:immunology*; D016207:Cytokines / Q000276:immunology; D007114:Immunization / Q000379:methods*; D007891:Leishmania / Q000276:immunology*; D016773:Leishmaniasis, Cutaneous / Q000276:immunology* / Q000469:parasitology / Q000517:prevention & control; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009569:Nitric Oxide / Q000276:immunology; D018709:Statistics, Nonparametric
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D016207:Cytokines; D009569:Nitric Oxide