Many airborne fungi are capable of causing disease by direct infection, toxicoses, or allergy. Allergy to fungi is common in asthma, particularly among individuals with severe asthma. Most fungi are unable to grow at body temperature, however, thermotolerant fungi, such as Aspergillus fumigatus, have the ability to act as both aeroallergens and as colonisers of the airway and are associated with poorer lung function [1,2].
Allergies in children and adults have increased, with studies suggesting this may result from increased susceptibility due to increased exposure to urban pollutants. Air pollution is the world’s largest single environmental health risk. Some pollutants affect the immune system and modulate airway diseases such as asthma by increasing the release of inflammatory mediators. There is evidence that air pollution may interact with airborne allergens such as pollens and fungal spores enhancing the risk of sensitisation and making symptoms of asthma and hayfever worse.
Most work has focused on pollens, and little is known about the interactions between pollutants and airborne fungal spores. Exposure to atmospheric CO2 and gaseous urban air pollution (NO2 and ozone) has been shown to increase the allergenicity of the fungus A. fumigatus [3,4], and exposure to organic pollutants have been shown to favour the development of pathogenic trade-offs in plant pathogenic fungi .
Particulate matter (PM) is the principal component of indoor and outdoor air pollution. Recent studies have shown that exposure to PM alters the behaviour of respiratory tract bacteria, changing bacterial biofilm composition, structure, and function . Many plant, animal and human fungal pathogens grow as biofilms.
The aim of this project is to determine whether exposure to PM or gaseous pollutants affect fungal behaviour in ways which could impact on plant and human health
1. To determine if black carbon, a major component of air pollution particulate matter, or gaseous pollutants can affect the growth rate, germination potential or biofilm formation ability of major plant and human fungal pathogens
2. To explore whether exposure to PM or gaseous pollutants can increase the allergenic potential of the fungi themselves or the human inflammatory response to the fungi
3. To investigate changes in the levels of proteins identified in the secretome in response to exposure of fungi to PM or gaseous pollutants
This project will focus on three fungal species: A. fumigatus, the most common human opportunistic filamentous fungus associated with asthma, COPD and cystic fibrosis, Candida albicans, a commensal yeast and common cause of human opportunistic fungal infection, and Alternaria alternata, a renowned human allergen and important plant pathogenic fungus. The effects of black carbon and gaseous pollutants on the growth and allergenicity of the fungi in their natural and biofilm forms will be studied. Furthermore, the impact of the pollutants on the human inflammatory response to the fungi will be investigated by exposing cells to fungi with and without pre-treatment with the pollutants.
Expected outcomes and impact
Poor air quality is the top environmental risk to public health in the UK. Fungal bioaerosols are grossly understudied and yet are a major component of the air and impact human health. Air pollution is a growing problem in the indoor and outdoor environment and is relevant to both developed and developing countries. Understanding the risk exposure to air pollution may have in enhancing atopic sensitisation and exacerbation of symptoms in sensitised individuals is critical to improving risk assessments and developing policies such as the Clean Air Strategy.
Experimental Methods, environment and supervision
This is an exciting, cross-disciplinary project with healthcare implications. You will learn a broad range of skills, including microbiological and mycological techniques, DNA and protein analysis, bioinformatics, proteomics, culture, ELISA, ex vivo models, imaging and Real Time PCR.
You will be based in Respiratory Sciences, but benefit from active links across the college including with respiratory and infectious disease clinicians, atmospheric chemists and the new centre for Environmental Health and Sustainability. Dr Pashley is a lecturer in aerobiology and clinical mycology with >15 years’ experience investigating the role of fungi in asthma and the UK’s longest outdoor pollen and fungal spore database. Prof. Morrissey is a Professor in the department of Genetics and Genome Biology with an active interest in pollution and antimicrobial resistance.
1. Fairs A, Agbetile J, Hargadon B, Bourne M, Monteiro WR, Brightling CE, Bradding P, Green RH, Mutalithas K, Desai D, Pavord ID, Wardlaw AJ, Pashley CH. IgE sensitization to Aspergillus fumigatus is associated with reduced lung function in asthma. Am J Respir Crit Care Med 2010; 182: 1362-1368.
2. Woolnough KF, Richardson M, Newby C, Craner M, Bourne M, Monteiro W, Siddiqui S, Bradding P, Pashley CH, Wardlaw AJ. The relationship between biomarkers of fungal allergy and lung damage in asthma. Clin Exp Allergy 2017; 47: 48-56.
3. Lang-Yona N, Levin Y, Dannemiller KC, Yarden O, Peccia J, Rudich Y. Changes in atmospheric CO2 influence the allergenicity of Aspergillus fumigatus. Glob Chang Biol 2013; 19: 2381-2388.
4. Lang-Yona N, Shuster-Meiseles T, Mazar Y, Yarden O, Rudich Y. Impact of urban air pollution on the allergenicity of Aspergillus fumigatus conidia: Outdoor exposure study supported by laboratory experiments. Sci Total Environ 2016; 541: 365-371.
5. Martins C, Varela A, Leclercq CC, Nunez O, Vetrovsky T, Renaut J, Baldrian P, Pereira CS. Specialisation events of fungal metacommunities exposed to a persistent organic pollutant are suggestive of augmented pathogenic potential. Microbiome 2018; 6: 13.
6. Hussey SJK, Purves J, Allcock N, Fernandes VE, Monks PS, Ketley JM, Andrew PW, Morrissey JA. Air pollution alters Staphylococcus aureus and Streptococcus pneumoniae biofilms, antibiotic tolerance and colonisation. Environ Microbiol 2017; 19: 1868-1880.