Transcriptional regulation of Munc13-4 expression in cytotoxic lymphocytes is disrupted by an intronic mutation associated with a primary immunodeficiency

J Exp Med. 2014 Jun 2;211(6):1079-91. doi: 10.1084/jem.20131131. Epub 2014 May 19.


Autosomal recessive mutations in UNC13D, the gene that encodes Munc13-4, are associated with familial hemophagocytic lymphohistiocytosis type 3 (FHL3). Munc13-4 expression is obligatory for exocytosis of lytic granules, facilitating cytotoxicity by T cells and natural killer (NK) cells. The mechanisms regulating Munc13-4 expression are unknown. Here, we report that Munc13-4 is highly expressed in differentiated human NK cells and effector CD8(+) T lymphocytes. A UNC13D c.118-308C>T mutation, causative of FHL3, disrupted binding of the ETS family member ELF1 to a conserved intronic sequence. This mutation impairs UNC13D intron 1 recruitment of STAT4 and the chromatin remodeling complex component BRG1, diminishing active histone modifications at the locus. The intronic sequence acted as an overall enhancer of Munc13-4 expression in cytotoxic lymphocytes in addition to representing an alternative promoter encoding a novel Munc13-4 isoform. Mechanistically, T cell receptor engagement facilitated STAT4-dependent Munc13-4 expression in naive CD8(+) T lymphocytes. Collectively, our data demonstrates how chromatin remodeling within an evolutionarily conserved regulatory element in intron 1 of UNC13D regulates the induction of Munc13-4 expression in cytotoxic lymphocytes and suggests that an alternative Munc13-4 isoform is required for lymphocyte cytotoxicity. Thus, mutations associated with primary immunodeficiencies may cause disease by disrupting transcription factor binding.

Publication types

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

MeSH terms

  • Blotting, Western
  • CD8-Positive T-Lymphocytes / immunology*
  • CD8-Positive T-Lymphocytes / metabolism
  • Cells, Cultured
  • Cytotoxicity, Immunologic / genetics
  • Cytotoxicity, Immunologic / immunology
  • DNA Helicases / genetics
  • DNA Helicases / immunology
  • DNA Helicases / metabolism
  • Gene Expression Regulation / immunology
  • Humans
  • Immunologic Deficiency Syndromes / genetics
  • Immunologic Deficiency Syndromes / immunology*
  • Immunologic Deficiency Syndromes / metabolism
  • Introns / genetics
  • Killer Cells, Natural / immunology*
  • Killer Cells, Natural / metabolism
  • Lymphohistiocytosis, Hemophagocytic / genetics
  • Lymphohistiocytosis, Hemophagocytic / immunology
  • Lymphohistiocytosis, Hemophagocytic / metabolism
  • Membrane Proteins / genetics
  • Membrane Proteins / immunology*
  • Membrane Proteins / metabolism
  • Nuclear Proteins / genetics
  • Nuclear Proteins / immunology
  • Nuclear Proteins / metabolism
  • Point Mutation / immunology*
  • Protein Binding / genetics
  • Protein Binding / immunology
  • Protein Isoforms / genetics
  • Protein Isoforms / immunology
  • Protein Isoforms / metabolism
  • RNA Interference
  • Reverse Transcriptase Polymerase Chain Reaction
  • STAT4 Transcription Factor / genetics
  • STAT4 Transcription Factor / immunology
  • STAT4 Transcription Factor / metabolism
  • Transcription Factors / genetics
  • Transcription Factors / immunology
  • Transcription Factors / metabolism


  • Membrane Proteins
  • Nuclear Proteins
  • Protein Isoforms
  • STAT4 Transcription Factor
  • STAT4 protein, human
  • Transcription Factors
  • UNC13D protein, human
  • SMARCA4 protein, human
  • DNA Helicases