Effect of different stages of Schistosoma mansoni infection on the parasite burden and immune response to Strongyloides venezuelensis in co-infected mice.
Multiple schistosome and soil-transmitted nematode infections are frequently reported in human populations living in tropical areas of developing countries. In addition to exposure factors, the host immune response plays an important role in helminth control and morbidity in hosts with multiple infections; however, these aspects are difficult to evaluate in human populations. In the current study, female Swiss mice were simultaneously co-infected with Strongyloides venezuelensis and Schistosoma mansoni or infected with St. venezuelensis at 2, 4, or 14 weeks after Sc. mansoni infection. The simultaneously infected mice showed a similar parasite burden for St. venezuelensis compared with mono-infected mice. In contrast, there was a significant reduction of St. venezuelensis burden (primarily during the migration of the larvae) in mice that were previously infected with Sc. mansoni at the acute or chronic phase. Independent of the stage of Sc. mansoni infection, the St. venezuelensis co-infection was capable of inducing IL-4 production in the small intestine, increasing the IgE concentration in the serum and increasing eosinophilia in the lungs and intestine. This result suggests that the nematode infection stimulates local type 2 immune responses independently of the schistosomiasis stage. Moreover, previous Sc. mansoni infection stimulated early granulocyte infiltration in the lungs and trematode-specific IgM and IgG1 production that recognized antigens from St. venezuelensis infective larvae; these immune responses would act in the early control of St. venezuelensis larvae. Our data suggest that the effect of multiple helminth infections on host susceptibility and morbidity largely depends on the species of parasite and the immune response.
Department of Parasitology, Institute of Biological Science, Federal University of Minas Gerais (UFMG), Block Q3-room 242, Antonio Carlos Avenue 6627, Campus Pampulha, Belo Horizonte, MG, 31270-901, Brazil.
Michelle Carvalho
MC
de Rezende
Department of Parasitology, Institute of Biological Science, Federal University of Minas Gerais (UFMG), Block Q3-room 242, Antonio Carlos Avenue 6627, Campus Pampulha, Belo Horizonte, MG, 31270-901, Brazil.
Emília Souza
ES
Araújo
Department of Parasitology, Institute of Biological Science, Federal University of Minas Gerais (UFMG), Block Q3-room 242, Antonio Carlos Avenue 6627, Campus Pampulha, Belo Horizonte, MG, 31270-901, Brazil.
João Marcelo Peixoto
JM
Moreira
Department of Parasitology, Institute of Biological Science, Federal University of Minas Gerais (UFMG), Block Q3-room 242, Antonio Carlos Avenue 6627, Campus Pampulha, Belo Horizonte, MG, 31270-901, Brazil.
Vanessa Fernandes
VF
Rodrigues
Department of Parasitology, Institute of Biological Science, Federal University of Minas Gerais (UFMG), Block Q3-room 242, Antonio Carlos Avenue 6627, Campus Pampulha, Belo Horizonte, MG, 31270-901, Brazil.
Jailza Lima
JL
Rodrigues
Department of Parasitology, Institute of Biological Science, Federal University of Minas Gerais (UFMG), Block Q3-room 242, Antonio Carlos Avenue 6627, Campus Pampulha, Belo Horizonte, MG, 31270-901, Brazil.
Cíntia A de Jesus
CA
Pereira
Department of Parasitology, Institute of Biological Science, Federal University of Minas Gerais (UFMG), Block Q3-room 242, Antonio Carlos Avenue 6627, Campus Pampulha, Belo Horizonte, MG, 31270-901, Brazil. denegrao@icb.ufmg.br.
Deborah
D
Negrão-Corrêa
D000818:Animals; D060085:Coinfection / Q000276:immunology* / Q000469:parasitology; D016207:Cytokines / Q000276:immunology; D005260:Female; D006801:Humans; D015847:Interleukin-4 / Q000276:immunology; D007421:Intestine, Small / Q000276:immunology / Q000469:parasitology; D008168:Lung / Q000276:immunology / Q000469:parasitology; D051379:Mice; D012550:Schistosoma mansoni / Q000254:growth & development* / Q000276:immunology; D012555:Schistosomiasis mansoni / Q000276:immunology* / Q000469:parasitology; D013321:Strongyloides / Q000254:growth & development* / Q000276:immunology; D013322:Strongyloidiasis / Q000276:immunology* / Q000469:parasitology
D016207:Cytokines; D015847:Interleukin-4
Co-infection; Cross-reactive antibody production; Schistosoma mansoni; Strongyloides venezuelensis; Tissue eosinophilia