Schistosoma mansoni antigens modulate experimental allergic asthma in a murine model: a major role for CD4+ CD25+ Foxp3+ T cells independent of interleukin-10.
In areas where schistosomiasis is endemic, a negative correlation is observed between atopy and helminth infection, associated with a low prevalence of asthma. We investigated whether Schistosoma mansoni infection or injection of parasite eggs can modulate airway allergic inflammation in mice, examining the mechanisms of such regulation. We infected BALB/c mice with 30 S. mansoni cercariae or intraperitoneally injected 2,500 schistosome eggs, and experimental asthma was induced by ovalbumin (OVA). The number of eosinophils in bronchoalveolar lavage fluid was higher in the asthmatic group than in asthmatic mice infected with S. mansoni or treated with parasite eggs. Reduced Th2 cytokine production, characterized by lower levels of interleukin-4 (IL-4), IL-5, and immunoglobulin E, was observed in both S. mansoni-treated groups compared to the asthmatic group. There was a reduction in the number of inflammatory cells in lungs of S. mansoni-infected and egg-treated mice, demonstrating that both S. mansoni infection and the egg treatment modulated the lung inflammatory response to OVA. Only allergic animals that were treated with parasite eggs had increased numbers of CD4(+) CD25(+) Foxp3(+) T cells and increased levels of IL-10 and decreased production of CCL2, CCL3, and CCL5 in the lungs compared to the asthmatic group. Neutralization of IL-10 receptor or depletion of CD25(+) T cells in vivo confirmed the critical role of CD4(+) CD25(+) Foxp3(+) regulatory T cells in experimental asthma modulation independent of IL-10.
Pacífico
Lucila G G
LG
Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, Pampulha, Belo Horizonte, MG, Brazil 31270-901.
Marinho
Fábio A V
FA
Fonseca
Cristina T
CT
Barsante
Michele M
MM
Pinho
Vanessa
V
Sales-Junior
Policarpo A
PA
Cardoso
Luciana S
LS
Araújo
Maria Ilma
MI
Carvalho
Edgar M
EM
Cassali
Geovanni D
GD
Teixeira
Mauro M
MM
Oliveira
Sergio C
SC
D000818:Animals; D000953:Antigens, Protozoan / Q000276:immunology*; D001249:Asthma / Q000276:immunology* / Q000517:prevention & control; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry / Q000166:cytology; D015496:CD4-Positive T-Lymphocytes / Q000737:chemistry / Q000276:immunology*; D016207:Cytokines / Q000032:analysis; D004804:Eosinophils / Q000276:immunology; D005260:Female; D005434:Flow Cytometry; D007073:Immunoglobulin E / Q000032:analysis; D053645:Interleukin-2 Receptor alpha Subunit / Q000032:analysis; D007958:Leukocyte Count; D008168:Lung / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D012550:Schistosoma mansoni / Q000276:immunology*; D012552:Schistosomiasis / Q000150:complications / Q000276:immunology*; D016176:T-Lymphocyte Subsets / Q000737:chemistry / Q000276:immunology*
D000953:Antigens, Protozoan; D016207:Cytokines; D053645:Interleukin-2 Receptor alpha Subunit; D007073:Immunoglobulin E