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

Abstract

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 (I sc ) response, which was mediated by a Ca 2+ -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 [Ca 2+ ] 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.

Trichomonas vaginalis infection impairs anion secretion in vaginal epithelium

“…Recent studies have demonstrated the impairment of transepithelial Cl − transport after infection with pathogens including C. jejuni [27], T. gondii [28], and influenza virus [44]. Here in our study, we verified that T. vaginalis infection significantly inhibited anion secretion elicited by the luminal administration of PGE 2 in rat vaginal epithelium.…”

“…Trichomoniasis has been demonstrated to be associated with severe adverse reproductive outcomes, such as infertility and multiple pregnancy complications [24][25][26], whilst the underlying mechanisms remain largely unclear. Recent studies showed that infection with pathogens including Campylobacter jejuni [27] and Toxoplasma gondii [28] impaired the function of analysis, decision to publish, or preparation of the manuscript.…”

Increased intracellular Cl− concentration promotes ongoing inflammation in airway epithelium

“…Cl − is the major anion responsible for transepithelial transportation in airway epithelium, whereas studies on Cl − mainly focused on its cellular-biological roles such as fluid secretion and cell volume regulation. 16 Numerous pro-inflammatory pathogens and particles, including P. aeruginosa, Toxoplasma gondii, H5N1 influenza virus hemagglutinin and cigarette smoke extracts, significantly suppressed Cl − secretion in airway epithelium, [33][34][35][36] indicating an intimate link between defective Cl − transport and airway infection. Unfortunately, whether disequilibrium in [Cl − ] i occurs after infection in airway epithelial cells has not been fully revealed.…”

Plant‐made oral vaccines against human infectious diseases—Are we there yet?

“…Infection by the intracellular parasitic protozoan Toxoplasma gondii can cause complications in pregnant women and in immunodeficient individuals such as patients with AIDS and organ transplant recipients (Guo et al, 2015). Recent studies have shown the possible roles of chronic toxoplasmosis infection in the aetiology of certain mental disorders, such as schizophrenia (Parlog et al, 2015).…”