Introduction: Recent evidence highlights neutrophils’ role in initiating/sustainingaberrant immune responses in type 1 diabetes (T1D). The PTPN22 C1858T variant,a risk factor for several autoimmune conditions including T1D, affects T/B-cellreceptor signaling. This study investigates its contribution to the alteredneutrophil activation and function in T1D.Materials and methods: Neutrophils were isolated from peripheral bloodmononuclear cells (PBMCs) of wild-type (WT) C1858C, heterozygous (HET)C1858T T1D patients, and healthy controls (HD). Reactive oxygen species (ROS)levels were assessed using a fluorogenic probe by Fluorescence- Activated CellSorting (FACS) in tumor necrosis factor-alpha (TNF-a) primed, unprimed-Nformylmethionyl-leucyl-phenylalanine (fMLP) stimulated, and primed-stimulatedneutrophils. Neutrophil adhesion/transmigration was evaluated via brightfield andepifluorescence microscopy on human umbilical vein endothelial cells (HUVECs).Results: Neutrophil counts were increased in the female patients than in HD.ROS production was enhanced in the neutrophils of the HET patients versus WTcontrols under the different culture conditions. Furthermore, ROS levels wereincreased in the HET (n = 10) versus WT (n = 6) patients (p < 0.05). Neutrophiladhesion to HUVECs and transmigration through the monolayer were increasedin the HET (n = 4) versus WT (n = 6) patients under both basal and TNF-aconditions (p < 0.0001).Conclusion: Neutrophils from C1858T patients are more intrinsically active withincreased ROS production and HUVEC adhesion/transmigration, suggestingenhanced contribution to the migration of other immunotypes from vesselsinto the pancreatic islets during T1D etiopathogenesis.
Effect of the autoimmune-associated genetic variant PTPN22 R620W on neutrophil activation and function in patients with insulin-dependent diabetes mellitus
Fierabracci A
2025-01-01
Abstract
Introduction: Recent evidence highlights neutrophils’ role in initiating/sustainingaberrant immune responses in type 1 diabetes (T1D). The PTPN22 C1858T variant,a risk factor for several autoimmune conditions including T1D, affects T/B-cellreceptor signaling. This study investigates its contribution to the alteredneutrophil activation and function in T1D.Materials and methods: Neutrophils were isolated from peripheral bloodmononuclear cells (PBMCs) of wild-type (WT) C1858C, heterozygous (HET)C1858T T1D patients, and healthy controls (HD). Reactive oxygen species (ROS)levels were assessed using a fluorogenic probe by Fluorescence- Activated CellSorting (FACS) in tumor necrosis factor-alpha (TNF-a) primed, unprimed-Nformylmethionyl-leucyl-phenylalanine (fMLP) stimulated, and primed-stimulatedneutrophils. Neutrophil adhesion/transmigration was evaluated via brightfield andepifluorescence microscopy on human umbilical vein endothelial cells (HUVECs).Results: Neutrophil counts were increased in the female patients than in HD.ROS production was enhanced in the neutrophils of the HET patients versus WTcontrols under the different culture conditions. Furthermore, ROS levels wereincreased in the HET (n = 10) versus WT (n = 6) patients (p < 0.05). Neutrophiladhesion to HUVECs and transmigration through the monolayer were increasedin the HET (n = 4) versus WT (n = 6) patients under both basal and TNF-aconditions (p < 0.0001).Conclusion: Neutrophils from C1858T patients are more intrinsically active withincreased ROS production and HUVEC adhesion/transmigration, suggestingenhanced contribution to the migration of other immunotypes from vesselsinto the pancreatic islets during T1D etiopathogenesis.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
