title: Concomitant helminth infection downmodulates the Vaccinia virus-specific immune response and potentiates virus-associated pathology.
abstract: The aim of this work was to elucidate the immunopathological mechanisms of how helminths may influence the course of a viral infection, using a murine model. Severe virulence, a relevant increase in the virus titres in the lung and a higher mortality rate were observed in Ascaris and Vaccinia virus (VACV) co-infected mice, compared with VACV mono-infected mice. Immunopathological analysis suggested that the ablation of CD8+T cells, the marked reduction of circulating CD4+T cells producing IFN-γ, and the robust pulmonary inflammation were associated with the increase of morbidity/mortality in co-infection and subsequently with the negative impact of concomitant pulmonary ascariasis and respiratory VACV infection for the host. On the other hand, when evaluating the impact of the co-infection on the parasitic burden, co-infected mice presented a marked decrease in the total number of migrating Ascaris lung-stage larvae in comparison with Ascaris mono-infection. Taken together, our major findings suggest that Ascaris and VACV co-infection may potentiate the virus-associated pathology by the downmodulation of the VACV-specific immune response. Moreover, this study provides new evidence of how helminth parasites may influence the course of a coincident viral infection.
authors.affiliation: Department of Parasitology, Biological Sciences Institute, Universidade Federal de Minas Gerais, Brazil.
authors.forename: Pedro Henrique
authors.initials: PH
authors.lastname: Gazzinelli-Guimarães
authors.affiliation: Department of Microbiology, Biological Sciences Institute, Universidade Federal de Minas Gerais, Brazil.
authors.forename: Lorena Falabella Daher
authors.initials: LF
authors.lastname: de Freitas
authors.affiliation: Department of Parasitology, Biological Sciences Institute, Universidade Federal de Minas Gerais, Brazil.
authors.forename: Ana Clara
authors.initials: AC
authors.lastname: Gazzinelli-Guimarães
authors.affiliation: Department of Microbiology, Biological Sciences Institute, Universidade Federal de Minas Gerais, Brazil.
authors.forename: Fabiana
authors.initials: F
authors.lastname: Coelho
authors.affiliation: Department of Parasitology, Biological Sciences Institute, Universidade Federal de Minas Gerais, Brazil.
authors.forename: Fernando Sérgio
authors.initials: FS
authors.lastname: Barbosa
authors.affiliation: Department of Parasitology, Biological Sciences Institute, Universidade Federal de Minas Gerais, Brazil.
authors.forename: Denise
authors.initials: D
authors.lastname: Nogueira
authors.affiliation: Department of Parasitology, Biological Sciences Institute, Universidade Federal de Minas Gerais, Brazil.
authors.forename: Chiara
authors.initials: C
authors.lastname: Amorim
authors.affiliation: Department of Parasitology, Biological Sciences Institute, Universidade Federal de Minas Gerais, Brazil.
authors.forename: Lucas de Carvalho
authors.initials: LC
authors.lastname: Dhom-Lemos
authors.affiliation: Department of Parasitology, Biological Sciences Institute, Universidade Federal de Minas Gerais, Brazil.
authors.forename: Luciana Maria
authors.initials: LM
authors.lastname: Oliveira
authors.affiliation: Department of Morphology, Biomedical Sciences Institute, Universidade Federal de Uberlândia, Brazil.
authors.forename: Alexandre Barcelos
authors.initials: AB
authors.lastname: da Silveira
authors.affiliation: Department of Microbiology, Biological Sciences Institute, Universidade Federal de Minas Gerais, Brazil.
authors.forename: Flávio Guimarães
authors.initials: FG
authors.lastname: da Fonseca
authors.affiliation: Department of Parasitology, Biological Sciences Institute, Universidade Federal de Minas Gerais, Brazil.
authors.forename: Lilian Lacerda
authors.initials: LL
authors.lastname: Bueno
authors.affiliation: Department of Parasitology, Biological Sciences Institute, Universidade Federal de Minas Gerais, Brazil. Electronic address: fujiwara@icb.ufmg.br.
authors.forename: Ricardo Toshio
authors.initials: RT
authors.lastname: Fujiwara
mesh_terms: D000818:Animals; D001196:Ascariasis / Q000276:immunology / Q000821:virology*; D001200:Ascaris / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D060085:Coinfection / Q000276:immunology* / Q000469:parasitology / Q000821:virology; D016207:Cytokines / Q000276:immunology; D004195:Disease Models, Animal; D005260:Female; D007371:Interferon-gamma / Q000276:immunology; D007814:Larva / Q000469:parasitology; D008168:Lung / Q000276:immunology / Q000469:parasitology / Q000473:pathology / Q000821:virology; D051379:Mice; D008807:Mice, Inbred BALB C; D011014:Pneumonia / Q000276:immunology / Q000469:parasitology* / Q000821:virology; D013552:Swine; D014615:Vaccinia / Q000209:etiology* / Q000276:immunology / Q000473:pathology / Q000821:virology; D014616:Vaccinia virus / Q000276:immunology*; D019562:Viral Load
chemical_list: D016207:Cytokines; C000611649:IFNG protein, mouse; D007371:Interferon-gamma
keywords: Helminth immunology; Immunomodulation; Larval ascariasis; Lung inflammation; Vaccinia virus, co-infection