Claire Jacquin-Porretaz, Marine Cordonnier, Charlée Nardin, Laura Boullerot, Gaetan Chanteloup, Valentin Vautrot, Olivier Adotevi, Carmen Garrido, Jessica Gobbo, François Aubin
DOI: 10.2340/00015555-3300

Exosomes are involved in modulating the immune system and mediating communication between cells. The aim of this study was to investigate the involvement of exosomes in psoriasis. Exosomes from patients with psoriasis were analysed by nanoparticle tracking analysis and protein expression was analysed by western blotting. The concentration of HSP70 was determined by an enzyme-linked immunosorbent assay, and concentrations of interleukin (IL)-1β, IL-2, IL-6, IL-10, IL-17A and tumour necrosis factor alpha (TNF-α) were determined by flow cytometry. Based on the severity of psoriasis, evaluated by body surface area (≤ 10% vs. > 10%), 2 groups of patients were compared (49 with mild psoriasis and 71 with moderate-to-severe psoriasis). The number (2.52×1011 ± 2.29×1010 vs. 1.79×1011 ± 1.93×1010, p = 0.19) and size (94.44 ± 22.00 nm vs. 96.87 ± 28.30 nm, p = 0.72) of exosomes and the concentration of HSP70 in the exosomes were not significantly different in the 2 groups of patients. IL-17A exosome levels were significantly higher in patients with moderate-to-severe psoriasis compared with those with mild psoriasis (p = 0.02). There were no significant differences in levels of TNF-α, IL-1, IL-2, IL-6 and IL-10. This study shows, for the first time, the presence of circulating exosomes in patients with psoriasis. These data confirm the involvement of circulating exosomes in psoriasis, in particular in moderate-to-severe psoriasis, through IL-17A-producing exosomes.

Exosomes are naturally occurring small membrane-enclosed nanovesicles that modulate the immune system and mediate communication between cells and the transport of cellular components. Although the field of exosome research in cancer progression is expanding, there are very few studies on the role of exosomes in immune-mediated inflammatory diseases. This study shows, for the first time, the presence of circulating exosomes in patients with psoriasis, in particular in those with moderate-to-severe psoriasis, through IL-17A-producing exosomes. Further, larger, studies are required, to evaluate the effect of systemic treat­ments on exosome production.