Defective Treg generation and increased type 3 immune response in leukocyte adhesion deficiency 1.

In 15 Turkish LAD-1 patients and controls, we assessed the impact of pathogenic ITGB2 mutations on Th17/Treg differentiation and functions, and innate lymphoid cell (ILC) subsets. The percentage of peripheral blood Treg cells, in vitro-generated induced Tregs differentiated from naive CD4 ⁺ T cells were decreased despite the elevated absolute counts of CD4 ⁺ cells in LAD-1 patients. Serum IL-23 levels were elevated in LAD-1 patients. Post-curdlan stimulation, LAD-1 patient-derived PBMCs produced more IL-17A. Additionally, the percentages of CD18-deficient Th17 cells expanded from total or naïve CD4 ⁺ T cells were higher. The blood ILC3 subset was significantly elevated in LAD-1. Finally, LAD-1 PBMCs showed defects in trans-well migration and proliferation and were more resistant to apoptosis. Defects in de novo generation of Tregs from CD18-deficient naïve T cells and elevated Th17s, and ILC3s in LAD-1 patients' peripheral blood suggest a type 3-skewed immunity and may contribute to LAD-1-associated autoimmune symptoms.
Competing Interests: Declaration of Competing Interest The authors declare no competing interest.
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