The expression profile of virus-recognizing toll-like receptors in natural killer cells of Cypriot multiple sclerosis patients

Elie Deeba,Christina Christodoulou,Marios Pantzaris,Anastasia Lambrianides,George Krashias

doi:10.1186/s13104-020-05300-1

Elie Deeba, Christina Christodoulou + Show 3 more

Open Access

https://doi.org/10.1186/s13104-020-05300-1

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Abstract

ObjectiveThe exact aetiology of multiple sclerosis (MS) remains elusive, although several environmental and genetic risk factors have been implicated to varying degrees. Among the environmental risk factors, viral infections have been suggested as strong candidates contributing to MS pathology/progression. Viral recognition and control are largely tasked to the NK cells via TLR recognition and various cytotoxic and immunoregulatory functions. Additionally, the complex roles of different TLRs in MS pathology are highlighted in multiple, often contradictory, studies. The present work aims to analyse the TLR expression profile of NK cells isolated from MS patients. Highly purified CD56+CD3− NK cells isolated from peripheral blood of MS patients (n = 19) and healthy controls (n = 20) were analysed via flow cytometry for their expression of viral antigen-recognizing TLRs (TLR2, TLR3, TLR7, and TLR9).ResultsNo difference was noted in TLR expression between MS patients and healthy controls. These results aim to supplement previous findings which study expressional or functional differences in TLRs present in various subsets of the immune system in MS, thus aiding in a better understanding of MS as a complex multifaceted disease.

Highlights

There is wide consensus defining multiple sclerosis (MS) as a chronic demyelinating disease, with studies showing apparent aspects of autoimmunity [1, 2]
The percentage expressions of TLR2, 3, 7, and 9 in the total Natural killer (NK) populations represented by the percentage positivity (%positivity) were not significantly different among MS and healthy controls (HC) samples (Fig. 2)
The expressions of the Toll-like receptor (TLR) per NK cell represented by the percentage Percentage mean fluorescence intensity (MFI) difference (%MFI) were not significantly different among MS and HCs samples (Fig. 3)

Summary

Results

The percentage expressions of TLR2, 3, 7, and 9 in the total NK populations represented by the percentage positivity (%positivity) were not significantly different among MS and HCs samples (Fig. 2). The expressions of the TLRs per NK cell represented by the percentage MFI difference (%MFI) were not significantly different among MS and HCs samples (Fig. 3). Upon analysing the %positivity (Fig. 2) and %MFI (Fig. 3) of the two separate subpopulations, no significant differences were found among MS and HC samples. The MS group was separated into MS patients receiving medication versus MS patients not receiving any medication at the time of sampling. Comparing %positivity and %MFI between these 2 groups showed no significant difference in TLR expression in either total NK cells, or the subsets of NK cells (CD56bright and CD56dim)

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