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Journal of Parasitology Research
Volume 2011, Article ID 512154, 8 pages
Review Article

Excretory-Secretory Products from Hookworm L3 and Adult Worms Suppress Proinflammatory Cytokines in Infected Individuals

1Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz, Avenida Augusto de Lima 1715, 30190-002 Belo Horizonte, MG, Brazil
2Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Avenida Antônio Carlos 6627, 31270-901 Belo Horizonte, MG, Brazil
3Department of Microbiology, Immunology, and Tropical Medicine, The George Washington University Medical Center, 2300 Eye Street NW, Washington, DC 20037, USA

Received 30 November 2010; Revised 18 March 2011; Accepted 29 March 2011

Academic Editor: Takeshi Agatsuma

Copyright © 2011 Stefan Michael Geiger et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


We compared the effects of larval and adult worm excretory-secretory (ES) products from hookworm on the proliferative responses and cytokine secretion in peripheral blood mononuclear cells (PBMCs) from hookwormpatients and egg-negative, nonendemic controls. When compared with negative controls, mitogen-stimulated PBMC from hookworm-infected individuals showed a significantly reduced proliferative response when adult worm ES antigen was added to the cultures. Furthermore, in hookworm-infected individuals a significant downmodulation of inflammatory interleukin (IL)-6 and tumor necrosis factor (TNF)- secretion resulted when PBMCs were stimulated with mitogen in combination with larval or adult worm ES. Both, interferon (IFN)- and IL-10 secretion were significantly lower in stimulated PBMC from infected individuals; however the IFN- /IL-10 ratio was much lower in hookworm-infected patients. Comparable effects, although at lower concentrations, were achieved when PBMCs from both groups were incubated with living hookworm third-stage larvae. We suggest that hookworm ES products downmodulate proliferative responses and inflammation during the chronic phase of the disease and facilitate early larval survival or adult worm persistence in the gut.