title: Established T(H1) granulomatous responses induced by active Mycobacterium avium infection switch to T(H2) following challenge with Schistosoma mansoni.
abstract: Mycobacterium avium established a systemic infection with granulomatous inflammation in mice. Mice chronically infected with M. avium and subsequently co-infected with Schistosoma mansoni developed additional, but morphologically distinct, hepatic granulomas. Schistosome eggs were not deposited in the spleen, and splenic granulomas in co-infected mice contained mycobacteria. In complete contrast to the T(H1) cytokine pattern observed with granuloma lymphocytes from M. avium-infected mice, granuloma lymphocytes from co-infected mice stimulated with PPD elaborated IL-4, but not IFN-gamma. Furthermore, mycobacterial granulomas in concurrently infected mice contained large numbers of eosinophils, a feature never seen in granulomas of M. avium-infected mice. Serum IgG1 and IgE levels in concurrently infected mice were significantly higher, but IgG2a levels significantly lower, than those in M. avium-infected mice, further evidence that the T(H1) component induced by M. avium is modulated subsequent to co-infection with S. mansoni. The dominance of the T(H2) response observed in this model could have clinical implications in areas where parasites and mycobacteria co-exist.
authors.affiliation: Department of Pathology, University of Iowa College of Medicine, Iowa City 52242, USA. rsacco@nadc.ars.usda.gov
authors.forename: Randy
authors.initials: R
authors.lastname: Sacco
authors.forename: Michael
authors.initials: M
authors.lastname: Hagen
authors.forename: Matyas
authors.initials: M
authors.lastname: Sandor
authors.forename: Joel V
authors.initials: JV
authors.lastname: Weinstock
authors.forename: Richard G
authors.initials: RG
authors.lastname: Lynch
mesh_terms: D000818:Animals; D005260:Female; D006099:Granuloma / Q000209:etiology* / Q000276:immunology; D007073:Immunoglobulin E / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D015847:Interleukin-4 / Q000096:biosynthesis; D051379:Mice; D008807:Mice, Inbred BALB C; D009162:Mycobacterium avium / Q000276:immunology*; D012555:Schistosomiasis mansoni / Q000276:immunology*; D018417:Th1 Cells / Q000276:immunology*; D018418:Th2 Cells / Q000276:immunology*; D014376:Tuberculosis / Q000276:immunology* / Q000473:pathology
chemical_list: D007074:Immunoglobulin G; D015847:Interleukin-4; D007073:Immunoglobulin E