Thursday, April 02, 2015

Infection by Toxoplasma gondii, a severe parasite in neonates and AIDS patients, causes impaired anion secretion in airway epithelia

2015 Mar 23. pii: 201503474. [Epub ahead of print]
The airway epithelia initiate and modulate the inflammatory responses to various pathogens. The cystic fibrosis transmembrane conductance regulator-mediated Cl- secretion system plays a key role in mucociliary clearance of inhaled pathogens. We have explored the effects of Toxoplasma gondii, an opportunistic intracellular protozoan parasite, on Cl- secretion of the mouse tracheal epithelia. In this study, ATP-induced Cl- secretion indicated the presence of a biphasic short-circuit current (Isc) response, which was mediated by a Ca2+-activated Cl- channel (CaCC) and the cystic fibrosis transmembrane conductance regulator. However, the ATP-evoked Cl- secretion in T. gondii-infected mouse tracheal epithelia and the elevation of [Ca2+]i in T. gondii-infected human airway epithelial cells were suppressed. Quantitative reverse transcription-PCR revealed that the mRNA expression level of the P2Y2 receptor (P2Y2-R) increased significantly in T. gondii-infected mouse tracheal cells. This revealed the influence that pathological changes in P2Y2-R had on the downstream signal, suggesting that P2Y2-R was involved in the mechanism underlying T. gondii infection in airways. These results link T. gondii infection as well as other pathogen infections to Cl- secretion, via P2Y2-R, which may provide new insights for the treatment of pneumonia caused by pathogens including T. gondii.


ATP; Cl− secretion; P2Y2 receptor; cystic fibrosis; pneumonia
[PubMed - as supplied by publisher]

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