Exploring immune responses of microplastics exposure using high-dimensional spectral flow cytometry

Micro- and nanoplastics (MNPs) pollution is of growing political and public concern. Human exposure to MNPs resides predominantly from ingestion and inhalation and MNPs have been detected in various human tissues. Animal and an vitro studies show that MNPs can be taken up by cells, causing chances in intracellular signaling pathways and affecting immune homeostasis. Little is known however of how MNPs may affect the human immune system on a global level in real life exposure scenario's. We have developed two complementary immunomonitoring panels for spectral flow cytometry, consisting of 69 markers in total to assess lineage and functional status of the major cell subsets in human peripheral blood. These panels identify B cells, monocytes, dendritic cells, T cells, natural killer (NK) cells, innate lymphoid cells (ILCs) and unconventional T cells. To investigate the potential immune responses of acute and chronic MNP exposure in humans, samples from two different exposure studies were used. One included healthy volunteers who had payed 4-hour visits to three different outdoor locations where expected traffic-related MNPs concentrations were low, medium and high. Blood samples were taken at the start and end of the visit and the next day. For the second study blood samples were taken from healthy workers in a textile factory, where fibrous MNPs are likely to be present in the air due to processing of the textiles. Office personnel from the same factory working in sections where expected MNPs exposure was low, served as controls. From all blood samples peripheral blood mononuclear cells (PBMCs) were isolated, stained with the two panels and acquired on the Cytek 5 Laser Aurora spectral flow cytometer. A combination of manual and unsupervised analysis will be applied to explore how MNPs may alter immune cell composition and activation. Also see: https://micro2024.sciencesconf.org/559440/document