title: Increased susceptibility to Strongyloides venezuelensis infection is related to the parasite load and absence of major histocompatibility complex (MHC) class II molecules.
abstract: In human and murine models strongyloidiasis induce a Th2 type response. In the current study we investigated the role of different loads of Strongyloides venezuelensis in the immune response raised against the parasite and the participation of the major histocompatibility complex (MHC) class II molecule in the disease outcome in face of the different parasite burden. The C57BL/6 wild type (WT) and MHC II(-/-) mice were individually inoculated by subcutaneous injection with 500 or 3000 S. venezuelensis L3. The MHC II(-/-) mice infected with 3000L3 were more susceptible to S. venezuelensis infection when compared with WT groups, in which the parasite was completely eliminated. The production of Th2 cytokines and specific IgG1 or IgE antibodies against parasite were significantly lowered in MHC II(-/-) infected mice with different larvae inoculums. The infection of MHC II(-/-) mice with S. venezuelensis induced slight inflammatory alterations in the small intestine, and these lesions were lower when compared with WT mice, irrespective of the parasite load utilized to infect animals. Finally, we concluded that MHC class II molecules are essential in the immune response against S. venezuelensis mainly when infection occurs with high parasite inoculum.
authors.affiliation: Laboratório de Diagnóstico de Parasitoses, Instituto de Ciências Biomédicas, Universidade Federal de Uberlândia, Av. Pará 1720, 38400-902 Uberlândia, MG, Brazil; Laboratório de Parasitologia, Universidade Federal de Goiás, Campus Jataí, GO, Brazil.
authors.forename: Rosângela Maria
authors.initials: RM
authors.lastname: Rodrigues
authors.forename: Cristina Ribeiro
authors.initials: CR
authors.lastname: Cardoso
authors.forename: Ana Lúcia Ribeiro
authors.initials: AL
authors.lastname: Gonçalves
authors.forename: Neide Maria
authors.initials: NM
authors.lastname: Silva
authors.forename: Virgínia
authors.initials: V
authors.lastname: Massa
authors.forename: Ronaldo
authors.initials: R
authors.lastname: Alves
authors.forename: Marlene Tiduko
authors.initials: MT
authors.lastname: Ueta
authors.forename: João Santana
authors.initials: JS
authors.lastname: Silva
authors.forename: Julia Maria
authors.initials: JM
authors.lastname: Costa-Cruz
mesh_terms: D000818:Animals; D000909:Antibodies, Helminth / Q000096:biosynthesis / Q000097:blood; D016207:Cytokines / Q000378:metabolism; D005243:Feces / Q000469:parasitology; D005260:Female; D005298:Fertility; D000949:Histocompatibility Antigens Class II / Q000235:genetics / Q000276:immunology*; D007073:Immunoglobulin E / Q000096:biosynthesis / Q000097:blood; D007074:Immunoglobulin G / Q000096:biosynthesis / Q000097:blood; D007421:Intestine, Small / Q000276:immunology / Q000469:parasitology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D059208:Parasite Load; D051381:Rats; D017208:Rats, Wistar; D013321:Strongyloides / Q000276:immunology* / Q000502:physiology; D013322:Strongyloidiasis / Q000276:immunology* / Q000469:parasitology
chemical_list: D000909:Antibodies, Helminth; D016207:Cytokines; D000949:Histocompatibility Antigens Class II; D007074:Immunoglobulin G; D007073:Immunoglobulin E
keywords: Immune response; MHC class II; Strongyloides venezuelensis; Strongyloidiasis