Event Abstract Back to Event Ultrastructural alterations in adult Schistosoma mansoni harbored in low-inflammatory mice. Aurelizia Maria L. Xavier1, Daniel Tavares2*, Erick V. Guimarães3, Antonio Carlos Da Silva2 and Antonio Henrique A. De Moraes Neto3 1 Universidade Federal Fluminense (UFF), Departamento de Imunobiologia (GIM), Brazil 2 Universidade do Estado do Rio de Janeiro (UERJ), Departamento de Genética (DGen), Brazil 3 Fundação Oswaldo Cruz, Instituto Oswaldo Cruz., Brazil Introduction: The Schistosoma mansoni infection was studied in two strains of mice genetically selected for extreme phenotypes of susceptibility (TS) and resistance (TR) to oral tolerance (Silva, AC et al. 1998). TR strain presents good inflammatory responses and a non-tolerogenic profile while TS strain presents non-inflammatory but high-tolerogenic profile, with high percentages of CD4+CD25+Foxp3+ T regulatory cells. Furthermore, TS strain is able to produce high levels of inhibitory citokynes such as IL-10 (Silva, MF et al. 2010). The aim of this work was to analyze by Transmission Electron Microscopy the influence of the host immune regulatory profile on the worm morphology. Material and Methods: TR and TS strains of mice from the F25 generation, obtained by two-way genetic selection according to susceptibility (TS) or resistance (TR) to ovalbumin oral tolerance (Silva, AC et al. 1998). TR and TS strains were exposed to 50 transcutaneous cercariae obtained from Reference Laboratory in Malacology of Instituto Oswaldo Cruz, FIOCRUZ, RJ, Brazil (Xavier, AML et al. 2010). The Committee for the Care and Use of Laboratory Animals of the Universidade do Estado do Rio de Janeiro, approved the protocols of the experiments described in this work (029/2010/UERJ). Adult worms obtained by perfusion of TS and TR mice 8 weeks after infection were collected from the portal and mesenteric veins in PBS pH 7.2 during necropsies of the abdominal cavity (Xavier, AML et al. 2010). For TEM, the previously fixed helminths in Karnovsky moisture for 2 h at room temperature. Post-fixation was conducted with 1.0% osmium tetroxide in cacodylate buffer + 0.8 % potassium ferricyanide + 5 mM CaCl2 and washed in 0.1 M cacodylate buffer. The worms were subsequently dehydrated in acetone series; embedded in Spurr’s resin; thin sections (60-70 nm) were collected on 300 mesh copper grids, counterstained with uranyl acetate and lead citrate, and finally, observed with a JEOL EM 1011 Transmission Electron Microscope of Microscopy Platform of Instituto Oswaldo Cruz, FIOCRUZ. Results: Parasites recovered from TR mice showed no morphological changes (Figure 1a-b) and specimens collected from TS mice, exhibited tubercle swelling with blunted and shortened spines in lower density (Figure 1c-d). Discussion: These tegument alterations were similar to those described with artemether or praziquantel treatment (Xiao et al 2002, Shuhua et al 2002), supporting observations that the host immune system influences the tegument development and function of worms harbored in non anti-helminthic treated TS mice. The higher percentage of dead eggs and similar quantities of collected eggs at ileum from TS mice compared to TR mice (Unpublished data), suggests that the alterations in adult worm tegument in TS mice prevented egg development, as a consequence of extensive lysis of internal structures, but not reduction of egg production. These results corroborate our previous Scanning Electron Microscopy study (Xavier, AML et al. 2010) indicating the influence of the host immune regulatory profile on the development and function of the worm reproductive system and tegument. Figure 1: Representative figures of tubercles from tegument hind region of adult male worms from TR (A and C) and TS (B and D) mice, showing tubercles. A-B: Micrographs by Scanning Electron Microscopy (SEM). C-D: Ultrastructural micrographs by Transmission Electron Microscopy (TEM). A and C: Tubercles from TR mice showed with spines (S) and regular internal structure (C). B and D: Tubercles from TS mice showed tubercles without spines. Five TR or TS mice of each sex were used. Bars: A: 2.5 µm B: 5 µm C: 2 µm ; D: 1 µm Figure 1 Acknowledgements We are grateful to Dra Lygia dos Reis Corrêa, Mr Paulo Cesar dos Santos and Mrs Heloisa from Laboratório de Malacologia, IOC, Fiocruz/RJ, for providing the cercariae of Schistosoma mansoni, and Drs Cid Couto and Marcia Giesta for care of the animal colonies (Laboratório de Imunobiologia). This work was supported by Plataforma de Microscopia Eletrônica do Instituto Oswaldo Cruz (IOC), Fundação Oswaldo Cruz (FIOCRUZ); Conselho Nacional de Desenvolvimento Científico e Tecnológico (MCT-CNPq); Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ) - Grant E-26/171.423/04. References Silva AC, Souza KW, Machado RC, Silva MFS, Sant'Anna OA. Genetics of immunological tolerance: I. Bidirectional selective breeding of mice for oral tolerance. Res. Immunol (1998)149: 151-161. Silva MF, Kamphorst AO, Hayashi EA, Bellio M, Carvalho CR, Faria AM, Sabino KC, Coelho MG, Nobrega A, Tavares D, Silva AC. Innate profiles of cytokines implicated on oral tolerance correlate with low- or high-suppression of humoral response. Immunology (2010) 130(3):447-57. Shuhua X, Binggui S, Utzinger J, Chollet J, Tanner M. Ultrastructural alterations in adult Schistosoma mansoni caused by Artemether. Mem Inst Oswaldo Cruz (2002) 97(5), 717–724. Tavares D, Ribeiro RC, Silva AC. Inflammatory lesion and parasite load are inversely associated in Leishmania amazonensis infected mice genetically selected according to oral tolerance susceptibility. Microbes Infect (2006) 8(4):957-64. Xavier AML, Magalhães JA, Cunha G dos S, Silva AC, Tavares DA, Sarro-Silva MF, de Moraes Neto AH. Morphological tegument alterations of adult Schistosoma mansoni, harbored in non anti-helminthic treated, high-immune-tolerogenic and low-inflammatory mice. Acta Trop (2010) 116(1):95-9. Xiao S, Shen, BG., Utzinger, J., Chollet, J., Tanner, M.,. Transmission electron microscopic observations on ultra-structural damage in juvenile Schistosoma mansoni caused by artemether. Acta Trop (2002) 81, 53–61. Keywords: Schistosoma mansoni, ultrastructure, Scanning electron microscopy, Transmission electron microscopy, tegument Conference: 15th International Congress of Immunology (ICI), Milan, Italy, 22 Aug - 27 Aug, 2013. Presentation Type: Abstract Topic: Host-pathogen interactions Citation: Xavier AL, Tavares D, Guimarães EV, Da Silva A and De Moraes Neto AA (2013). Ultrastructural alterations in adult Schistosoma mansoni harbored in low-inflammatory mice.. Front. Immunol. Conference Abstract: 15th International Congress of Immunology (ICI). doi: 10.3389/conf.fimmu.2013.02.01094 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 29 Jun 2013; Published Online: 22 Aug 2013. * Correspondence: Prof. Daniel Tavares, Universidade do Estado do Rio de Janeiro (UERJ), Departamento de Genética (DGen), Rio de Janeiro, Rio de Janeiro, 20550-013, Brazil, tavares.uerj@gmail.com Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Aurelizia Maria L Xavier Daniel Tavares Erick V Guimarães Antonio Carlos Da Silva Antonio Henrique A De Moraes Neto Google Aurelizia Maria L Xavier Daniel Tavares Erick V Guimarães Antonio Carlos Da Silva Antonio Henrique A De Moraes Neto Google Scholar Aurelizia Maria L Xavier Daniel Tavares Erick V Guimarães Antonio Carlos Da Silva Antonio Henrique A De Moraes Neto PubMed Aurelizia Maria L Xavier Daniel Tavares Erick V Guimarães Antonio Carlos Da Silva Antonio Henrique A De Moraes Neto Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.