Editors' ChoiceHost-Pathogen Interactions

Tricky Tryps

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Science Signaling  31 Jul 2012:
Vol. 5, Issue 235, pp. ec203
DOI: 10.1126/scisignal.2003439

African trypanosomes, responsible for human sleeping sickness, are known for their powerful strategies of immune evasion, in particular antigenic variation. Adding another facet to this adaptive potential, Salmon et al. now show that early after infection, these parasites subvert the first line of innate host defense by inhibiting tumor necrosis factor–α synthesis in myeloid cells. This occurs through the stress-induced synthesis and release of cyclic adenosine monophosphate by phagocytosed parasites. The findings provide a long-sought function for the abundant and diverse adenylate cyclases in salivarian trypanosomes. Furthermore, this altruistic host colonization strategy, in which a proportion of parasites are sacrificed so that others can thrive, also highlights the selective advantage of population behavior in infection.

D. Salmon, G. Vanwalleghem, Y. Morias, J. Denoeud, C. Krumbholz, F. Lhommé, S. Bachmaier, M. Kador, J. Gossmann, F. B. S. Dias, G. De Muylder, P. Uzureau, S. Magez, M. Moser, P. De Baetselier, J. Van Den Abbeele, A. Beschin, M. Boshart, E. Pays, Adenylate cyclases of Trypanosoma brucei inhibit the innate immune response of the host. Science 337, 463–466 (2012). [Abstract] [Full Text]