title: T regulatory cell responses to immunization with a soluble egg antigen in Schistosoma mansoni-infected mice.
abstract: The aim of the study is to characterize the phenotypes of CD4(+) CD25(+) T regulatory cells within the liver granulomas and association with both Foxp-3 gene expression and splenic cytokines. Naïve C57BL/6 mice were intravenously injected with multiple doses of the soluble egg antigen (SEA) 7 days before cercarial infection. The immunized and infected control groups were sacrificed 8 and 16 weeks post-infection (PI). Histopathology, parasitological parameters, splenic phenotypes for T regulatory cells, the FOXP-3 expression in hepatic granuloma using real-time PCR, and the associated splenic cytokines were studied. Histopathological examination of the liver revealed remarkable increase in degenerated ova within hepatic granuloma which decreased in diameter at weeks 8 and 16 PI (P<0.01). The percentage of T regulatory cells (CD4(+) CD25(+)) increased significantly (P<0.01) in the immunized group compared to the infected control at weeks 8 and 16 PI. The FOXP-3 expression in hepatic granulomas increased from 10 at week 8 to 30 fold at week 16 PI in the infected control group. However, its expression in the immunized group showed an increase from 30 at week 8 to 70 fold at week 16 PI. The splenic cytokine levels of pro-inflammatory cytokines, IFN-γ, IL-4, and TNF-α, showed significant decreases (P<0.05) compared to the infected control group. In conclusion, the magnitude and phenotype of the egg-induced effects on T helper responses were found to be controlled by a parallel response within the T regulatory population which provides protection in worm parasite-induced immunopathology.
authors.affiliation: Department of Immunology, Theodor Bilharz Research Institute, Imbaba, Giza, Egypt.
authors.forename: Eman
authors.initials: E
authors.lastname: El-Ahwany
authors.forename: Ibrahim Rabia
authors.initials: IR
authors.lastname: Bauiomy
authors.forename: Faten
authors.initials: F
authors.lastname: Nagy
authors.forename: Rabab
authors.initials: R
authors.lastname: Zalat
authors.forename: Ola
authors.initials: O
authors.lastname: Mahmoud
authors.forename: Suher
authors.initials: S
authors.lastname: Zada
mesh_terms: D000818:Animals; D000909:Antibodies, Helminth / Q000276:immunology; D000947:Antigens, Helminth / Q000008:administration & dosage / Q000276:immunology*; D016207:Cytokines / Q000235:genetics / Q000276:immunology; D000071316:Forkhead Box Protein O3; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000276:immunology; D006099:Granuloma / Q000276:immunology* / Q000469:parasitology; D006801:Humans; D007114:Immunization; D051379:Mice; D008807:Mice, Inbred BALB C; D012550:Schistosoma mansoni / Q000235:genetics / Q000276:immunology*; D012555:Schistosomiasis mansoni / Q000235:genetics / Q000276:immunology* / Q000469:parasitology; D013154:Spleen / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*
chemical_list: D000909:Antibodies, Helminth; D000947:Antigens, Helminth; D016207:Cytokines; D000071316:Forkhead Box Protein O3; D051858:Forkhead Transcription Factors; C474033:FoxO3 protein, mouse