Editors' ChoiceParasitology

Taking Advantage of the Host

Science's STKE  05 Nov 2002:
Vol. 2002, Issue 157, pp. tw406-TW406
DOI: 10.1126/stke.2002.157.tw406

The tick-borne protozoan parasites Theileria spp. (related to the malaria parasites, Plasmodium spp.) cause a cancer-like disease in cattle that is of major economic importance in Africa and Asia. Heussler et al. show how this pathogen subverts its host's signaling pathway for its own good. The schizont stage of the parasite infects the B and T cells of the immune system and immortalizes them into tumor-like cells capable of metastasis. Transformation seems to occur because the parasite activates the nuclear factor-κB (NF-κB) pathway and prevents apoptosis. This activation cannot be blocked by treatment with drugs that affect steps in the NF-κB signaling pathway upstream of multisubunit IκB kinase (IKK). The authors show that the intracellular foci of Theileria are associated with recruitment and aggregation of the IKK signalsome complex. Such aggregation seems to be sufficient to activate the kinase and subsequently activate NF-κB.

V. T. Heussler, S. Rottenberg, R. Schwab, P. Küenzi, P. C. Fernandez, S. McKellar, B. Shiels, Z. J. Chen, K. Orth, D. Wallach, D. A. E. Dobbelaere, Hijacking of host cell IKK signalosomes by the transforming parasite Theileria. Science 298, 1033-1036 (2002). [Abstract] [Full Text]