P2X7 Receptor-Mediated Killing of an Intracellular Parasite, Toxoplasma gondii, by Human and Murine Macrophages

J Immunol. 2010 May 19. [Epub ahead of print]

P2X7 Receptor-Mediated Killing of an Intracellular Parasite, Toxoplasma gondii, by Human and Murine Macrophages

Lees MP, Fuller SJ, McLeod R, Boulter NR, Miller CM, Zakrzewski AM, Mui EJ, Witola WH, Coyne JJ, Hargrave AC, Jamieson SE, Blackwell JM, Wiley JS, Smith NC.

Institute for the Biotechnology of Infectious Diseases, University of Technology, Sydney, Broadway;

Abstract
The P2X(7)R is highly expressed on the macrophage cell surface, and activation of infected cells by extracellular ATP has been shown to kill intracellular bacteria and parasites. Furthermore, single nucleotide polymorphisms that decrease receptor function reduce the ability of human macrophages to kill Mycobacterium tuberculosis and are associated with extrapulmonary tuberculosis. In this study, we show that macrophages from people with the 1513C (rs3751143, NM_002562.4:c.1487A>C) loss-of-function P2X(7)R single nucleotide polymorphism are less effective in killing intracellular Toxoplasma gondii after exposure to ATP compared with macrophages from people with the 1513A wild-type allele. Supporting a P2X(7)R-specific effect on T. gondii, macrophages from P2X(7)R knockout mice (P2X(7)R(-/-)) are unable to kill T. gondii as effectively as macrophages from wild-type mice. We show that P2X(7)R-mediated T. gondii killing occurs in parallel with host cell apoptosis and is independent of NO production.

PMID: 20488797 [PubMed - as supplied by publisher]