Selective loss of function variants in IL6ST cause Hyper-IgE syndrome with distinct impairments of T-cell phenotype and function


Shahin T. , Aschenbrenner D., Cagdas D., Bal S. K. , Conde C. D. , Garncarz W., ...More

HAEMATOLOGICA, vol.104, no.3, pp.609-621, 2019 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 104 Issue: 3
  • Publication Date: 2019
  • Doi Number: 10.3324/haematol.2018.194233
  • Title of Journal : HAEMATOLOGICA
  • Page Numbers: pp.609-621

Abstract

Hyper-IgE syndromes comprise a group of inborn errors of immunity. STAT3-deficient hyper-IgE syndrome is characterized by elevated serum IgE levels, recurrent infections and eczema, and characteristic skeletal anomalies. A loss-of-function biallelic mutation in IL6ST encoding the GP130 receptor subunit (p.N404Y) has very recently been identified in a singleton patient (herein referred to as P-N404Y) as a novel etiology of hyper-IgE syndrome. Here, we studied a patient with hyper-IgE syndrome caused by a novel homozygous mutation in IL6ST (p.P498L; patient herein referred to as P-P498L) leading to abrogated GP130 signaling after stimulation with IL-6 and IL-27 in peripheral blood mononuclear cells as well as IL-6 and IL-11 in fibroblasts. Extending the initial identification of selective GP130 deficiency, we aimed to dissect the effects of aberrant cytokine signaling on T-helper cell differentiation in both patients. Our results reveal the importance of IL-6 signaling for the development of CCR6-expressing memory CD4(+) T cells (including T-helper 17-enriched subsets) and non-conventional CD8(+) T cells which were reduced in both patients. Downstream functional analysis of the GP130 mutants (p.N404Y and p.P498L) have shown differences in response to IL-27, with the p.P498L mutation having a more severe effect that is reflected by reduced T-helper 1 cells in this patient (P-P498L) only. Collectively, our data suggest that characteristic features of GP130-deficient hyper-IgE syndrome phenotype are IL-6 and IL-11 dominated, and indicate selective roles of aberrant IL-6 and IL-27 signaling on the differentiation of T-cell subsets.