Environmentally weathered polystyrene particles induce phenotypical and functional maturation of human monocyte-derived dendritic cells

• Published in: Journal of immunotoxicology Vol. 19; no. 1; pp. 125 - 133
• Main Authors: van den Berg, Annemijne E. T., Plantinga, Maud, Vethaak, Dick, Adriaans, Kas J., Bol-Schoenmakers, Marianne, Legler, Juliette, Smit, Joost J., Pieters, Raymond H. H.
• Format: Journal Article
• Language: English
• Published: England Taylor & Francis 01.12.2022; Taylor & Francis Ltd; Taylor & Francis Group
• Subjects: adjuvant effect; Adjuvants, Immunologic; Antigen-presenting cells; CD83 antigen; CD86 antigen; Cell activation; Cell proliferation; Dendritic Cells; Humans; immune sensitization; immunotoxicology; Lymphocyte Activation; Lymphocytes T; Micro- and nanoplastics; Monocytes; Polystyrene; Polystyrenes - toxicity; Surface markers; immune sensitization; adjuvant effect; Micro- and nanoplastics; polystyrene; immunotoxicology
• ISSN: 1547-691X; 1547-6901
• DOI: 10.1080/1547691X.2022.2143968

Micro- and nanoplastics (MNP) are ubiquitously present in the environment due to their high persistence and bioaccumulative properties. Humans get exposed to MNP via various routes and consequently, they will encounter dendritic cells (DC) which are antigen-presenting cells involved in regulating immune responses. The consequences of DC exposure to MNP are an important, yet understudied, cause of concern. Therefore, this study aimed to assess the uptake and effect of MNP in vitro by exposing human monocyte-derived dendritic cells (MoDC) to virgin and environmentally weathered polystyrene (PS) particles of different sizes (0.2, 1, and 10 µm), at different concentrations ranging from 1 to 100 µg/ml. The effects of these particles were examined by measuring co-stimulatory surface marker (i.e. CD83 and CD86) expression. In addition, T-cell proliferation was measured via a mixed-leukocyte reaction (MLR) assay. The results showed that MoDC were capable of absorbing PS particles, and this was facilitated by pre-incubation in heat-inactivated (HI) plasma. Furthermore, depending on their size, weathered PS particles in particular caused increased expression of CD83 and CD86 on MoDC. Lastly, weathered 0.2 µm PS particles were able to functionally activate MoDC, leading to an increase in T-cell activation. These in vitro data suggest that, depending on their size, weathered PS particles might act as an immunostimulating adjuvant, possibly leading to T-cell sensitization.