Impact of Mycotoxins Secreted by Aspergillus Molds on the Inflammatory Response of Human Corneal Epithelial Cells

Yélian Bossou,Isabelle Momas,Amel Allou,Sandrine Vitry,Youssra Serssar,Nathalie Seta,Sophie Achard,Jean Menotti

doi:10.3390/toxins9070197

Abstract

Exposure to molds and mycotoxins not only contributes to the onset of respiratory disease, it also affects the ocular surface. Very few published studies concern the evaluation of the effect of mycotoxin exposure on ocular cells. The present study investigates the effects of aflatoxin B1 (AFB1) and gliotoxin, two mycotoxins secreted by Aspergillus molds, on the biological activity of the human corneal epithelial (HCE) cells. After 24, 48, and 72 h of exposure, cellular viability and inflammatory response were assessed. Both endpoint cell viability colorimetric assays and continuous cell impedance measurements, providing noninvasive real-time assessment of the effect on cells, were performed. Cytokine gene expression and interleukin-8 release were quantified. Gliotoxin appeared more cytotoxic than AFB1 but, at the same time, led to a lower increase of the inflammatory response reflecting its immunosuppressive properties. Real-time cell impedance measurement showed a distinct profile of cytotoxicity for both mycotoxins. HCE cells appeared to be a well-suited in vitro model to study ocular surface reactivity following biological contaminant exposure. Low, but persistent inflammation, caused by environmental factors, such as fungal toxins, leads to irritation and sensitization, and could be responsible for allergic manifestations which, in turn, could lead to mucosal hyper-reactivity.

Highlights

Mycotoxins are common contaminants of agricultural crops produced by several genera of fungi, such as Aspergillus molds, in response to both intrinsic and extrinsic factors, such as, respectively, toxigenic status of fungi and temperature and humidity [1]
In order to evaluate the effects of aflatoxin B1 (AFB1) and gliotoxin on the ocular cells (HCE), we conducted two experimental approaches
In a first approach, using classical in vitro assays, both cellular viability and inflammatory response, interleukin-8 (IL-8) release, and gene expression quantification of seven inflammatory markers were assessed at different times and concentrations of mycotoxins

Summary

Introduction

Mycotoxins are common contaminants of agricultural crops produced by several genera of fungi, such as Aspergillus molds, in response to both intrinsic and extrinsic factors, such as, respectively, toxigenic status of fungi and temperature and humidity [1] These toxins can enter into the food chain, leading to adverse effects on animal and human health at low concentrations [2]. Some studies have established an association between low-level exposure to molds and mycotoxins, and asthma or chronic airway inflammation, especially among workers in an agricultural setting [9,12] Such exposure is related to the onset of farmers’ lung disease [13], hypersensitivity pneumonia, and allergic bronchopulmonary aspergillosis [14]. This type of exposure concerns the ocular surface, leading to irritations or allergic manifestations [15]

Results

Discussion

Conclusion