Abstract
Purpose :
To examine the tear fluid for the presence of host defence proteins induced by infecting pathogenic filamentous fungi, A. flavus.
Methods :
Tear fluid was collected from A.flavus keratitis patients during the early stage of infection using capillary tubes. Pooled tear samples were fractionated using lectin affinity chromatography and/or by 1D SDS-PAGE. Proteins were then subjected to tryptic digestion and taken for identification using Orbitrap Velos Pro mass spectrometer. iSRM analysis of selected proteins were done using triple quadrupole mass spectrometer.
Results :
Proteins that show variable levels indicate the activation of all the three complement pathways, antifungal neutrophil defence in the form of NETosis, along with inflammatory and wound healing responses. Proteins indicative of these processes are found at higher levels in tear from keratitis patients. Since these observations are made using early stage tear, presumably proteins secreted by the fungus or the fungal surface proteins could be responsible for this host response. Functional role of these proteins will be presented.
Conclusions :
Activation of pathways involved in defence against invading pathogens in the early stage of infection suggests that the host generates a robust antifungal defence. Despite this, a subset of the keratitis patients are still susceptible to fungal infection. This could probably be due to the fungal induced inhibitors that could either directly or indirectly (by activating inhibitory host response) attenuate the robust host response against infection.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.