T Cell Transcriptomes from Paroxysmal Nocturnal Hemoglobinuria Patients Reveal Novel Signaling Pathways

J Immunol. 2017 Jul 15;199(2):477-488. doi: 10.4049/jimmunol.1601299. Epub 2017 Jun 19.

Abstract

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare acquired disorder originating from hematopoietic stem cells and is a life-threating disease characterized by intravascular hemolysis, bone marrow (BM) failure, and venous thrombosis. The etiology of PNH is a somatic mutation in the phosphatidylinositol glycan class A gene (PIG-A) on the X chromosome, which blocks synthesis of the glycolipid moiety and causes deficiency in GPI-anchored proteins. PNH is closely related to aplastic anemia, in which T cells mediate destruction of BM. To identify aberrant molecular mechanisms involved in immune targeting of hematopoietic stem cells in BM, we applied RNA-seq to examine the transcriptome of T cell subsets (CD4+ naive, CD4+ memory, CD8+ naive, and CD8+ memory) from PNH patients and healthy control subjects. Differentially expressed gene analysis in four different T cell subsets from PNH and healthy control subjects showed distinct transcriptional profiles, depending on the T cell subsets. By pathway analysis, we identified novel signaling pathways in T cell subsets from PNH, including increased gene expression involved in TNFR, IGF1, NOTCH, AP-1, and ATF2 pathways. Dysregulation of several candidate genes (JUN, TNFAIP3, TOB1, GIMAP4, GIMAP6, TRMT112, NR4A2, CD69, and TNFSF8) was validated by quantitative real-time RT-PCR and flow cytometry. We have demonstrated molecular signatures associated with positive and negative regulators in T cells, suggesting novel pathophysiologic mechanisms in PNH. These pathways may be targets for new strategies to modulate T cell immune responses in BM failure.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't
  • Research Support, N.I.H., Intramural

MeSH terms

  • Activating Transcription Factor 2 / genetics
  • Activating Transcription Factor 2 / metabolism
  • Adult
  • CD30 Ligand / genetics
  • CD30 Ligand / metabolism
  • CD4-Positive T-Lymphocytes / immunology
  • Female
  • Gene Expression Profiling
  • Gene Expression Regulation / immunology
  • Hemoglobinuria, Paroxysmal / immunology*
  • Hemoglobinuria, Paroxysmal / metabolism
  • Hemoglobinuria, Paroxysmal / physiopathology
  • Humans
  • Insulin-Like Growth Factor I / genetics
  • Insulin-Like Growth Factor I / metabolism
  • Male
  • Metabolic Networks and Pathways / genetics*
  • Methyltransferases / genetics
  • Methyltransferases / metabolism
  • Middle Aged
  • Real-Time Polymerase Chain Reaction
  • Sequence Analysis, RNA
  • Signal Transduction / genetics
  • T-Lymphocyte Subsets / immunology*
  • T-Lymphocyte Subsets / metabolism
  • Transcriptome*
  • Tumor Necrosis Factor alpha-Induced Protein 3 / genetics
  • Tumor Necrosis Factor alpha-Induced Protein 3 / metabolism
  • Young Adult

Substances

  • ATF2 protein, human
  • Activating Transcription Factor 2
  • CD30 Ligand
  • IGF1 protein, human
  • TNFSF8 protein, human
  • Insulin-Like Growth Factor I
  • Methyltransferases
  • TRMT112 protein, human
  • TNFAIP3 protein, human
  • Tumor Necrosis Factor alpha-Induced Protein 3