Through a qualitative analysis of the use of intestinal parasites for treating immune system disorders, this research illustrates how contingency emerges in the context of the human relationship to hookworms. The affect of the human–nonhuman relationship is an important part of understanding the direction of evolutionary medicine today, and has implications for the politics of biological health innovations. The shift from the bad parasite to a parasite that at least sometimes heals, discursively and materially, has opened new spaces for patients to change the way they relate to medical knowledge, medical professionals, and pharmaceutical companies. Hookworms are banned by the FDA, which sets the scene for lively, but sometimes rebellious, hybridity between host and parasite. Underground and do-it-yourself hookworm therapy cultures have sprung up in around the site of the gut. I argue that not only is material hookworm affect as important as human discourses in negotiating the rapidly advancing field of biome reconstruction, but it also plays a role in how that biome reconstruction takes place, conventionally or otherwise.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-11-01T14:25:20Z No. of bitstreams: 1 anamariadocarmo.pdf: 1166968 bytes, checksum: 902990ead7a531c64f6dd70ebcabe511 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-12-15T13:33:36Z (GMT) No. of bitstreams: 1 anamariadocarmo.pdf: 1166968 bytes, checksum: 902990ead7a531c64f6dd70ebcabe511 (MD5) / Made available in DSpace on 2016-12-15T13:33:36Z (GMT). No. of bitstreams: 1 anamariadocarmo.pdf: 1166968 bytes, checksum: 902990ead7a531c64f6dd70ebcabe511 (MD5) Previous issue date: 2008-02-28 / Sabe-se que existem inúmeros trabalhos envolvendo a modulação da resposta imune ao Mycobacterium. No entanto, o número de indivíduos apresentando tuberculose é cada vez maior. A resposta imune ao Mycobacterium é desencadeada principalmente por linfócitos Th1, com a produção de IFN-γ. As parasitoses intestinais também representam um importante problema médico-sanitário, tendo em vista o grande número de pessoas acometidas e as inúmeras alterações orgânicas que podem provocar no hospedeiro. Essas infecções helmínticas induzem preferencialmente uma resposta Th2 com a produção de IL-4, IL-5 e IL-13. Este trabalho avaliou a regulação da resposta imune no pulmão de camundongos co-infectados ou não por S. venezuelensis (SV) e/ou Mycobacterium bovis-BCG (MB), em dois pontos das duas infecções, denominados como ponto 1 (4° e 7° dia pós-imunização [dpi]) e ponto 2 (7° e 10° dpi) por MB e SV, respectivamente. Os animais foram infectados com 700 larvas de SV pela via subcutânea e, após 3 dias, com 1x106 UFC de MB cepa selvagem pela via intravenosa. Realizou-se a quantificação do número de ovos e vermes, a dosagem de citocinas (IFN-γ, IL-4 e IL-10) e quimiocinas (CCL2 e CCL5), o envolvimento de MPO e EPO, a detecção da infecção pelo MB por PCR, a avaliação histopatológica e a expressão de moléculas coestimulat órias/imunomodulatórias (CD80, CD86, CD28, CTLA-4 e CD25) em células ou tecidos do pulmão dos animais infectados e/ou co-infectados. Os resultados mostraram que a presença do MB favoreceu para o aumento do número de ovos e vermes do SV observados nos animais nos dias 4° e 7° (ponto 1) e 7° e 10° (ponto 2) após a infecção por MB e SV, respectivamente, nos animais co-infectados (COIN). A reação de PCR foi efetiva em detectar a presença do MB no pulmão dos animais. Foi observado um aumento de IFN-γ e uma diminuição de IL-4 e EPO no pulmão dos animais do grupo COIN, além de aumento na expressão da molécula co-estimulatória CD80 no ponto 1 e uma diminuição no ponto 2. Houve uma alta produção de IL-10 no pulmão dos animais dos grupos MB e COIN, sendo que a histopatologia neste sítio mostrou formação de granulomas com grande influxo de neutrófilos, macrófagos e células epitelóides na periferia nos pulmões dos animais do grupo MB e um granuloma bem mais avançado, com centro necrótico nos animais do grupo COIN. Baseado nesses resultados, conclui-se que o MB modula a infecção pelo SV, fazendo com que os animais fiquem mais suscetíveis à infecção helmíntica. Por outro lado, o SV modula a infecção pelo MB, fazendo com haja uma modificação na formação de granuloma no pulmão dos animais do grupo COIN no ponto 1 da infecção pelo MB, que poderia ser justificada pela diminuição de IL-4 nos animais do grupo COIN. / A rising number of people have been contracting tuberculosis around the world even though a multitude of reports involving a modulation of the immune response to Mycobacterium have been published. The response to Mycobacterium is mainly mediated by Th1 lymphocytes through IFN-gamma production. Parasitic diseases account for a large proportion of human morbidity and mortality, considering the number of people affected by them and several pathologies associated to parasitic infection. Helminthic infections drive towards Th2 response which leads to IL-4, IL5 and IL-13 production. The present study evaluated the immune response of coinfected animals or not with Strongyloides venezuelensis (SV) and Mycobacterium bovis-BCG (MB) on pulmonary cells collected from BALB/c mice at time points 1 (4th and 7th days post-immunization [dpi] by MB and SV, respectively) and 2 (7th and 10th dpi by MB and SV, respectively). Animals were infected with 700 SV larvae subcutaneously, and 3 days after, 1x106 CFU of wild MB strain intravenously. The number of worms and eggs was counted as well as cytokine (IFN-gamma, IL-4 and IL-10) and chemokine (CCL2 and CCL5) assessments, and the MPO and EPO levels determination on pulmonary tissue from infected and/or coinfected animals. In addition, PCR for MB detection, the histopathology and the expression of costimulatory molecules such as CD80, CD86, CD28, CTLA-4 and CD25 on pulmonary tissue were also assessed. The results pointed that MB led to increase SV parasite burden in coinfected mice (COIN) at both time points analyzed. The PCR technique detected effectively MB. Moreover, elevated IFN-gamma and reduced IL-4 and EPO levels were detected on pulmonary tissue in the COIN group. In regard to CD80 molecule, there was an increased expression at time point 1 and diminished expression at time point 2. Also, higher amounts of IL-10 were found on pulmonary tissue in MB and COIN groups. The histopathological analysis revealed pulmonary granulomas with a number of neutrophils, macrophages and epithelial cells-like in the MB group as well as granulomas in an advanced stage with caseous necrosis in the COIN group. Based on these findings, it may be concluded that MB modulated the immune response to SV, leading coinfected animals to be more susceptible to helminthic infection. On the other hand, SV modulated the MB infection by modifying the characteristics of the pulmonary granulomas in the COIN group at time point 1 probably due the reduced IL-4 production in this group.

L'objectif de cette étude était de mieux comprendre les relations entre les infections parasitaires, les réponses au stress physiologique et la condition corporelle des poissons. Nous avons pêché des crapets-soleil (Lepomis gibbosus) infectés naturellement par des douves et ténias (Apophallus sp., Uvulifer sp. et Proteocephalus ambloplitis) du lac Cromwell dans la région laurentienne du Québec et nous les avons soumis à différents traitements de stress aigu en laboratoire. Les niveaux de cortisol dans le plasma ont été mesurés à l’aide de la radio-immunoanalyse (RIA) et l’indice de condition de Fulton K ont été calculés pour chaque individu. Les individus avec une densité plus élevée d’Apophallus sp. et Uvulifer sp. présentaient une meilleure condition corporelle, tandis que ceux qui étaient plus fortement infectés par P.ambloplitis en avaient une plus pauvre. Les réponses au cortisol à la suite d’un stress aigu différaient d’un traitement à l’autre : les poissons ayant reçu le traitement d’un stress aigu unique présentaient des réponses au cortisol plasmatique significativement plus élevées, alors que tous les autres traitements montraient des niveaux de cortisol plus faibles. Cependant, ces différences de taux de cortisol n’étaient pas significativement liées à la densité parasitaire ou à la condition corporelle. Ces résultats suggèrent que, bien que la charge parasitaire influence la condition corporelle, elle ne semble pas affecter les réponses de cortisol causées par le stress. L’absence de relations significatives pourrait être liée à la présence réduite de certains phénotypes dans l’échantillon, ce qui pourrait révéler des tendances écologiques notables sur le cycle de vie des parasites. / The objective of this study was to better understand the relationships among parasite infection, physiological stress responses and the body condition of fish. We collected pumpkinseed sunfish (Lepomis gibbosus) naturally infected with helminthic flukes and tapeworms (Apophallus sp., Uvulifer sp., and Proteocephalus ambloplitis) from Lake Cromwell in the Quebec Laurentian region and subjected them to different stress treatments in the laboratory. Plasma cortisol levels were measured using radioimmunoassay (RIA), and Fulton's condition index K was calculated for each individual. Individuals with higher densities of Apophallus sp. and Uvulifer sp. had better body condition, while those more heavily infected with P. ambloplitis were in poorer condition. Cortisol responses following acute stress differed across treatments: fish that received the single acute stress treatment showed significantly higher plasma cortisol responses, whereas all other treatments showed lower cortisol levels. However, these differences in cortisol were not significantly related to parasite density or body condition. These results suggest that while parasite load influences body condition, it does not appear to directly affect stress-induced cortisol responses. The lack of significant relationships might be linked to the reduced presence of certain phenotypes in the sample, which may reveal important ecological trends on the parasite life cycle.