Exogenous interleukin‐2 can rescue in‐vitro in‐vitro T cell activation and proliferation in patients with a novel capping protein regulator and myosin 1 linker 2 mutation

摘要

Summary Capping protein regulator and myosin 1 linker 2 (CARMIL2) deficiency is characterized by impaired T cell activation, which is attributed to defective CD28‐mediated co‐signaling. Herein, we aimed to analyze the effect of exogenous interleukin (IL)‐2 on in‐vitro T cell activation and proliferation in a family with CARMIL2 deficiency. This study included four children (one male and three females; aged 2·5–10 years at presentation). The patients presented with inflammatory bowel disease and recurrent viral infections. Genetic analysis revealed a novel homozygous 25‐base pairs deletion in CARMIL2 . Immunoblotting demonstrated the absence of CARMIL2 protein in all four patients and confirmed the diagnosis of CARMIL2 deficiency. T cells were activated in‐vitro with the addition of IL‐2 in different concentrations. CD25 and interferon (IFN)‐γ levels were measured after 48?h and 5?days of activation. CD25 surface expression on activated CD8 + and CD4 + T cells was significantly diminished in all patients compared to healthy controls. Additionally, CD8 + T cells from all patients demonstrated significantly reduced IFN‐γ production. When cells derived from CARMIL2‐deficient patients were treated with IL‐2, CD25 and IFN‐γ production increased in a dose‐dependent manner. T cell proliferation, as measured by Cell Trace Violet, was impaired in one patient and it was also rescued with IL‐2. In conclusion, we found that IL‐2 rescued T cell activation and proliferation in CARMIL2‐deficient patients. Thus, IL‐2 should be further studied as a potential therapeutic modality for these patients.