TY - JOUR
T1 - Divergent TLR2 and TLR4 Activation by Fungal Spores and Species Diversity in Dust from Waste Sorting Plants
AU - Afanou, Anani K.
AU - Mundra, Sunil
AU - Estensmo, Eva Lena Fjeld
AU - Pedersen, Ine
AU - Liland, Jens Rasmus
AU - Eriksen, Elke
AU - Graff, Pål
AU - Hildre, Tonje Trulssen
AU - Nordby, Karl Christian
AU - Straumfors, Anne
N1 - Funding Information:
This work was financially supported by the Norwegian Confederation of Industry (Norsk Industri) and the National Institute of Occupational Health (STAMI). We thank Kari Kulvik Heldal for advice and support.
Publisher Copyright:
Copyright © 2023 Afanou et al. This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license.
PY - 2023/3
Y1 - 2023/3
N2 - This manuscript presents the results of an exploratory study on the relationships between NF-kB response through Toll-like receptor (TLR) activation by dust characterized by fungal spore concentrations and species diversity. Personal total dust samples were collected from Norwegian waste sorting plants and then characterized for fungal spores and fungal species diversity, as well as for other bioaerosol components, including endotoxins and actinobacteria. The ability of the dust to induce an NF-kB response by activating TLR2 and TLR4 in vitro was evaluated, as well as the relationship between such responses and quantifiable bioaerosol components. The average concentrations of bioaerosols were 7.23 mg total dust m23, 4.49 x 105 fungal spores m23, 814 endotoxin units m23, and 0.6 x 105 actinobacteria m23. The mean diversity measurements were 326, 0.59, and 3.39 for fungal richness, evenness, and Shannon index, respectively. Overall, fungal operational taxonomic units (OTUs) belonging to the Ascomycota phylum were most abundant (55%), followed by Basidiomycota (33%) and Mucoromycota (3%). All samples induced significant NF-kB responses through TLR2 and TLR4 activation. While fungal spore levels were positively associated with TLR2 and TLR4 activation, there was a trend that fungal species richness was negatively associated with the activation of these receptors. This observation supports the existence of divergent immunological response relationships between TLR activation and fungal spore levels on one hand and between TLR activation and fungal species diversity on the other. Such relationships seem to be described for the first time for dust from waste facilities. IMPORTANCE This manuscript presents results on multifactorial characterization of bioaerosol exposure in Norwegian waste sorting plants and the potential of such airborne dust to induce NF-kB reactions through TLR2 and TLR4 activations in an in vitro reporter cell model system. Our data revealed that increasing fungal spore levels in the dust is associated with increased activation of TLR2 and TLR4, whereas increasing fungal OTU richness is associated with decreasing activation of these receptors. The NF-kB-induced responses by the collected dust represent, therefore, effective measures of potential key immunological effects induced by a complex mixture of hazardous components, including characterized factors such as endotoxins, fungal spores, bacteria, and many other uncharacterized components. The key immunological events reported here are suggested as holistic alternatives to today’s bioaerosol exposure characterization approaches for epidemiological studies in the future.
AB - This manuscript presents the results of an exploratory study on the relationships between NF-kB response through Toll-like receptor (TLR) activation by dust characterized by fungal spore concentrations and species diversity. Personal total dust samples were collected from Norwegian waste sorting plants and then characterized for fungal spores and fungal species diversity, as well as for other bioaerosol components, including endotoxins and actinobacteria. The ability of the dust to induce an NF-kB response by activating TLR2 and TLR4 in vitro was evaluated, as well as the relationship between such responses and quantifiable bioaerosol components. The average concentrations of bioaerosols were 7.23 mg total dust m23, 4.49 x 105 fungal spores m23, 814 endotoxin units m23, and 0.6 x 105 actinobacteria m23. The mean diversity measurements were 326, 0.59, and 3.39 for fungal richness, evenness, and Shannon index, respectively. Overall, fungal operational taxonomic units (OTUs) belonging to the Ascomycota phylum were most abundant (55%), followed by Basidiomycota (33%) and Mucoromycota (3%). All samples induced significant NF-kB responses through TLR2 and TLR4 activation. While fungal spore levels were positively associated with TLR2 and TLR4 activation, there was a trend that fungal species richness was negatively associated with the activation of these receptors. This observation supports the existence of divergent immunological response relationships between TLR activation and fungal spore levels on one hand and between TLR activation and fungal species diversity on the other. Such relationships seem to be described for the first time for dust from waste facilities. IMPORTANCE This manuscript presents results on multifactorial characterization of bioaerosol exposure in Norwegian waste sorting plants and the potential of such airborne dust to induce NF-kB reactions through TLR2 and TLR4 activations in an in vitro reporter cell model system. Our data revealed that increasing fungal spore levels in the dust is associated with increased activation of TLR2 and TLR4, whereas increasing fungal OTU richness is associated with decreasing activation of these receptors. The NF-kB-induced responses by the collected dust represent, therefore, effective measures of potential key immunological effects induced by a complex mixture of hazardous components, including characterized factors such as endotoxins, fungal spores, bacteria, and many other uncharacterized components. The key immunological events reported here are suggested as holistic alternatives to today’s bioaerosol exposure characterization approaches for epidemiological studies in the future.
KW - TLR2
KW - TLR4
KW - bioaerosols
KW - mycobiome
KW - waste workers
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U2 - 10.1128/aem.01734-22
DO - 10.1128/aem.01734-22
M3 - Article
C2 - 36856441
AN - SCOPUS:85151312398
SN - 0099-2240
VL - 89
JO - Applied and Environmental Microbiology
JF - Applied and Environmental Microbiology
IS - 3
ER -