Table 4.

Overview of in vivo studies of the immunotoxic effects of nano- and microplastics in vertebrates. *This has been calculated by the authors based on Bachmanov AA et al. Behav Genet 2002 [73]

Reference	Nano-microplastics	Dosage	Duration of exposure	Route of exposure	Species	Observed immunotoxic effects
Nanoplastics
Greven et al., Environ. Toxicol. Chem. 2016 [111]	Polystyrene 41 nm	0.025–0.05-0.1- 0.2 μg/μL	2 h	Tank water	Fathead minnows (Pimephales promelas)	Neutrophil function in vitro assays Dose dependent ↑myeloperoxidase activity and neutrophil extracellular trap release
Brandts et al., Genomics. 2018 [112]	Polymethylmethacrylate ~ 45 nm	0.02–0.2-2-20 mg/L	96 h	Tank water	European sea bass (Dicentrarchus Labrax)	Plasma ↓ esterase activity (biomarker of oxidative stress) (0.02 and 0.2 mg/L)
Microplastics
Greven et al., Environ. Toxicol. Chem. 2016 [111]	Polycarbonate 158.7 nm	0.025–0.05-0.1- 0.2 μg/μL	2 h	Tank water	Fathead minnows (Pimephales promelas)	Neutrophil function in vitro assays Dose dependent ↑ myeloperoxidase activity, neutrophil extracellular trap release, and oxidative burst
Asmoniate et al., Environ. Sci.Technol.2018 [79]	Polystyrene 100–400 μm	10 mg /fish/day	4 weeks	Food	Rainbow trout (Oncorhynchus mykiss)	No variation of immune parameters: serum lysosyme activity blood immune cells counts
Banaee et al., Chemosphere 2019 [113]	Isolated from body scrub (likely polyethylene) No data on size	250 and 500 μg/L	30 days	Tank water	Common carp (Cyprinus carpio)	Plasma ↓total immunoglobulin ↓alternative complement activity ↓ complement C3 ↓complement C4 ↓lysozyme activity ↓acetylcholinesterase activity ↓γ-glutamyl-transferase activity ↑ lactate deshydrogenase activity ↑alkaline phosphatase activity
Espinosa et al., Fish Shellfish Immunol. 2017 [114]	Polyvinyl chloride 40–150 μm	100–500 mg/kg of food	15, 30 days	Food	Gilthead seabream (Sparus aurata)	↑ head-kidney leucocyte phagocytic capacity (15 days only)
Espinosa et al., Environ. Pollut. 2018 [115]	Polyvinyl chloride - Polyethylene 40–150 μm	1–10-100 mg/mL	1 h 24 h	Tank water	European sea bass (Dicentrarchus Labrax) Gilthead seabream (Sparus aurata)	Head-kidney leucocytes European sea bass PVC: ↓phagocytic capacity (all dosages, 1 h and 24 h) PE: ↑ respiratory burst (100 mg/mL, 24 h) Gilthead seabream PVC: ↓phagocytic ability, ↑ respiratory burst (100 mg/mL, 24 h) PVC and PE: ↑ Nrf2 expression (100 mg/mL, 1 h)
Espinosa et al., Fish Shellfish Immunol. 2019 [88]	Polyvinyl chloride - Polyethylene 40–150 μm	100–500 mg/kg of food	3 weeks	Food	European sea bass (Dicentrarchus Labrax)	Cellular innate immune parameters in head kidney leucocytes PVC: ↑ phagocytic capacity at both dosages ↑ respiratory burst activity at 100 mg/kg PE: ↑ respiratory burst activity at both dosages
Limonta et al., Sci rep 2019 [90]	Irregularly shaped high density polyethylene and polystyrene particles	100 and 1000 μg/L	20 days	Food	Zebrafish (Danio rerio)	↓ liver leukotriene B4 receptor (ltb4r) and interferon induced transmembrane protein 1 (ifitm1) expression
Li et al., Chemosphere. 2020 [93]	Polyethylene 10–150 μm	2–20-200 μg/g ~  0.0004, 0.004 and 0.04 μg/kg bw/day*	5 weeks	Food	C57BL/6 mice (Mus musculus)	At 20 and 200 μg/g: serum:↑ IL1α, ↓G-CSF spleen:↓Treg cells, ↑Th17 cells
Park et al., Toxicology Letters 2020 [116]	Polyethylene irregular micropsheres 16.9 ± 1.9 μm	0.125, 0.5 and 2 mg/day/mouse ~  5, 20 an 80 μg/kg bw/day*	90 days	Gavage	ICR mice (Mus musculus)	In dams: ↑ blood neutrophils ↑ blood IgA levels In dams and offspring: alteration of spleen lymphocytes