Rabbit Anti-Human IL2RA monoclonal antibody, clone TQ287

Background: A number of heritable immune dysregulatory diseases result from defects affecting regulatory T (Treg) cell development, function, or both. They include immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome, which is caused by mutations in forkhead box P3 (FOXP3), and IPEX-like disorders caused by mutations in IL-2 receptor a (IL2RA), signal transducer and activator of transcription 5b (STAT5b), and signal transducer and activator of transcription 1 (STAT1). However, the genetic defects underlying many cases of IPEX-like disorders remain unknown. Objective: We sought to identify the genetic abnormalities in patients with idiopathic IPEX-like disorders. Methods: We performed whole-exome and targeted gene sequencing and phenotypic and functional analyses of Treg cells. Results: A child who presented with an IPEX-like syndrome and severe Treg cell deficiency was found to harbor a nonsense mutation in the gene encoding LPS-responsive beige-like anchor (LRBA), which was previously implicated as a cause of common variable immunodeficiency with autoimmunity. Analysis of subjects with LRBA deficiency revealed marked Treg cell depletion; profoundly decreased expression of canonical Treg cell markers, including FOXP3, CD25, Helios, and cytotoxic T lymphocyte-associated antigen 4; and impaired Treg cellmediated suppression. There was skewing in favor of memory T cells and intense autoantibody production, with marked expansion of T follicular helper and contraction of T follicular regulatory cells. Whereas the frequency of recent thymic emigrants and the differentiation of induced Treg cells were normal, LRBA-deficient T cells exhibited increased apoptosis and reduced activities of the metabolic sensors mammalian target of rapamycin complexes 1 and 2. Conclusion: LRBA deficiency is a novel cause of IPEX-like syndrome and Treg cell deficiency associated with metabolic dysfunction and increased apoptosis of Treg cells.

BackgroundElevated protein expressions of CD markers such as IL2RA/CD25, CXCR4/CD184, CD34 and CD56 are associated with adverse prognosis in acute myeloid leukemia (AML). However, the prognostic value of mRNA expressions of these CD markers in AML remains unclear. Through our pilot evaluation, IL2RA mRNA expression appeared to be the best candidate as a prognostic biomarker. Therefore, the aim of this study is to characterize the prognostic value of IL2RA mRNA expression and evaluate its potential to refine prognostification in AML.MethodsIn a cohort of 239 newly diagnosed AML patients, IL2RA mRNA expression were measured by TaqMan realtime quantitative PCR. Morphological, cytogenetics and mutational analyses were also performed. In an intermediate-risk AML cohort with 66 patients, the mRNA expression of prognostic biomarkers (BAALC, CDKN1B, ERG, MECOM/EVI1, FLT3, ID1, IL2RA, MN1 and WT1) were quantified by NanoString technology. A TCGA cohort was analyzed to validate the prognostic value of IL2RA. For statistical analysis, Mann-Whitney U test, Fisher exact test, logistic regression, Kaplan-Meier and Cox regression analyses were used.ResultsIn AML cohort of 239 patients, high IL2RA mRNA expression independently predicted shorter relapse free survival (RFS, p<0.001) and overall survival (OS, p<0.001) irrespective of age, cytogenetics, FLT3-ITD or c-KIT D816V mutational status. In core binding factor (CBF) AML, high IL2RA mRNA expression correlated with FLT3-ITD status (p=0.023). Multivariable analyses revealed that high IL2RA expression (p=0.002), along with c-KIT D816V status (p=0.013) significantly predicted shorter RFS, whereas only high IL2RA mRNA expression (p=0.014) significantly predicted shorter OS in CBF AML. In intermediate-risk AML in which multiple gene expression markers were tested by NanoString, IL2RA significantly correlated with ID1 (p=0.006), FLT3 (p=0.007), CDKN1B (p=0.033) and ERG (p=0.030) expressions. IL2RA (p<0.001) and FLT3 (p=0.008) expressions remained significant in predicting shorter RFS, whereas ERG (p=0.008) and IL2RA (p=0.044) remained significant in predicting shorter OS. Similar analyses in TCGA intermediate-risk AML showed the independent prognostic role of IL2RA in predicting event free survival (p<0.001) and OS (p<0.001).ConclusionsHigh IL2RA mRNA expression is an independent and adverse prognostic factor in AML and specifically stratifies patients to worse prognosis in both CBF and intermediate-risk AML.