Xenobiotics and Pathogenicity of Avian Influenza Viruses

Research on potentially transmissible respiratory infectious diseases between humans and animals is of great interest following recent discussions regarding Covid-19 origins in wild animals. Particularly, given the ever-growing rate of pollution, the infectious diseases whose occurrence rates may be affected by the pollutants must be examined much more closely. According to available data, certain pollutants may impair immune responses as well as increase the susceptibility of hosts to viral infections. Influenza viruses can be transmitted from animals to humans resulting in epidemics and pandemics. As influenza viruses are potential candidates for the next catastrophic human pandemic, it is imperative to improve our knowledge regarding the environmental and molecular factors affecting the pathogenesis of the infection. In nature, wild waterbirds are the main reservoir of all subtypes of avian influenza viruses (AIVs), and different subtypes replicate in epithelial cells of the respiratory and intestinal tracts of these birds to varying degrees of pathogenicity. Chemical compounds found within an organism that are not naturally produced or expected to be present are referred to as xenobiotics. These highly persistent and recalcitrant xenobiotics are produced in a variety of industries and released into the environment through wastes, microplastics, fuels, and incomplete combustion. A few epidemiological and animal studies have shown that exposure to xenobiotic pollutants can increase the pathologic effects of influenza virus infections. It is well known that many wildlife species, including waterbirds, are chronically exposed to a variety of xenobiotic chemicals that can impair their immune function. They can enter human and animal bodies through contact with contaminated water, air, soil, and diets, disrupting a variety of molecular pathways, including those related to viruses and AIV subtypes. There is no comprehensive study on the impact of xenobiotics on AIV infections in wild waterbirds, even though an elevated incidence of influenza virus infection has already been linked to exposure to xenobiotic-containing environmental pollutants. Our aim is to determine how certain xenobiotics influence the pathogenicity of AIV subtypes in reservoir birds and human cells. The study may lead to a better understanding of how different xenobiotics influence the infection process of influenza viruses in their primary reservoirs, and if AhR molecular pathways play a role in this process.