Cellular responses and cytokine production in post-treatment hookworm patients from an endemic area in Brazil

Authors

  • S. M. GEIGER,

    Corresponding author
    1. Fundação Oswaldo Cruz, Centro de Pesquisas René Rachou, Laboratório de Imunologia, Belo Horizonte-MG, Brazil
    2. Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany
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  • C. L. MASSARA,

    1. Fundação Oswaldo Cruz, Centro de Pesquisas René Rachou, Laboratório de Imunologia, Belo Horizonte-MG, Brazil
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  • J. BETHONY,

    1. Fundação Oswaldo Cruz, Centro de Pesquisas René Rachou, Laboratório de Imunologia, Belo Horizonte-MG, Brazil
    2. George Washington University, Department of Microbiology and Tropical Medicine, Washington DC, USA
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  • P. T. SOBOSLAY,

    1. Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany
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  • R. CORRÊA-OLIVEIRA

    1. Fundação Oswaldo Cruz, Centro de Pesquisas René Rachou, Laboratório de Imunologia, Belo Horizonte-MG, Brazil
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Dr Stefan Geiger, Institute for Comparative Tropical Medicine and Parasitology, University of Munich, Leopoldstraße 5, 80802 Munich, Germany.
E-mail: stefan.geiger@tropa.vetmed.uni-muenchen.de

SUMMARY

Human hookworm infections are distributed widely in tropical areas and have a significant impact on host morbidity and human health. In the present study, we investigated the cellular responsiveness and cytokine production in peripheral blood mononuclear cells (PBMC) from Necator americanus-infected schoolchildren who had recently received chemotherapy, and compared them with non-infected endemic controls. Hookworm patients and treated, egg-negative individuals showed a lower cellular reactivity against phytohaemagglutinin (PHA) and hookworm antigen when compared with egg-negative endemic controls. The baseline production of proinflammatory tumour necrosis factor-α (TNF-α) in PBMC from infected patients and treated, egg-negative individuals was elevated. On the other hand, PHA- or hookworm antigen-induced interleukin (IL)-12 and interferon (IFN)-γ secretion was higher in endemic controls than in hookworm patients, who either continued egg-positive or were egg-negative after treatment. Also, PBMC from endemic controls secreted more IL-5 and IL-13 than the other patient groups. Opposite to that, the spontaneous as well as the antigen-driven IL-10 secretion was lower in endemic controls when compared with the other groups. In summary, patently hookworm-infected as well as egg-negative treated patients disclosed an elevated spontaneous cellular secretion of proinflammatory TNF-α, a prominent secretion of regulatory Th2-type IL-10 and an impaired production of IL-12, IFN-γ, IL-5 and IL-13.

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