Transcriptional regulation of Munc13-4 expression in cytotoxic lymphocytes is disrupted by an intronic mutation associated with a primary immunodeficiency.
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.
Centre for Infectious Medicine, Department of Medicine; Clinical Genetics Unit, Department of Molecular Medicine and Surgery, and Center for Molecular Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, 141 86 Stockholm, Sweden Division of Hematology, Oncology and Transplantation, University of Minnesota Cancer Center, Minneapolis, MN 55455.
Frank
F
Cichocki
Centre for Infectious Medicine, Department of Medicine; Clinical Genetics Unit, Department of Molecular Medicine and Surgery, and Center for Molecular Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, 141 86 Stockholm, Sweden.
Heinrich
H
Schlums
Basic Science Program, Leidos Biomedical Research, Inc., Laboratory of Experimental Immunology, SAIC-Frederick Inc., Frederick National Laboratory, Frederick, MD 21702.
Hongchuan
H
Li
Centre for Infectious Medicine, Department of Medicine; Clinical Genetics Unit, Department of Molecular Medicine and Surgery, and Center for Molecular Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, 141 86 Stockholm, Sweden.
Vanessa
V
Stache
Centre for Infectious Medicine, Department of Medicine; Clinical Genetics Unit, Department of Molecular Medicine and Surgery, and Center for Molecular Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, 141 86 Stockholm, Sweden.
Timothy
T
Holmes
Division of Hematology, Oncology and Transplantation, University of Minnesota Cancer Center, Minneapolis, MN 55455.
Todd R
TR
Lenvik
Centre for Infectious Medicine, Department of Medicine; Clinical Genetics Unit, Department of Molecular Medicine and Surgery, and Center for Molecular Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, 141 86 Stockholm, Sweden.
Samuel C C
SC
Chiang
Division of Hematology, Oncology and Transplantation, University of Minnesota Cancer Center, Minneapolis, MN 55455.
Jeffrey S
JS
Miller
Centre for Infectious Medicine, Department of Medicine; Clinical Genetics Unit, Department of Molecular Medicine and Surgery, and Center for Molecular Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, 141 86 Stockholm, Sweden Childhood Cancer Research Unit, Department of Women's and Children's Health, Karolinska Institutet, Karolinska University Hospital Solna, 171 76 Stockholm, Sweden.
Marie
M
Meeths
Basic Science Program, Leidos Biomedical Research, Inc., Laboratory of Experimental Immunology, SAIC-Frederick Inc., Frederick National Laboratory, Frederick, MD 21702.
Stephen K
SK
Anderson
Centre for Infectious Medicine, Department of Medicine; Clinical Genetics Unit, Department of Molecular Medicine and Surgery, and Center for Molecular Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, 141 86 Stockholm, Sweden Broegelmann Research Laboratory, Clinical Institute, University of Bergen, N-5021 Bergen, Norway yenan.bryceson@ki.se.
Yenan T
YT
Bryceson
D015153:Blotting, Western; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic / Q000235:genetics / Q000276:immunology; D004265:DNA Helicases / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D005786:Gene Expression Regulation / Q000276:immunology; D006801:Humans; D007153:Immunologic Deficiency Syndromes / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D007438:Introns / Q000235:genetics; D007694:Killer Cells, Natural / Q000276:immunology* / Q000378:metabolism; D051359:Lymphohistiocytosis, Hemophagocytic / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D017354:Point Mutation / Q000276:immunology*; D011485:Protein Binding / Q000235:genetics / Q000276:immunology; D020033:Protein Isoforms / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D034622:RNA Interference; D020133:Reverse Transcriptase Polymerase Chain Reaction; D050797:STAT4 Transcription Factor / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000276:immunology / Q000378:metabolism
D008565:Membrane Proteins; D009687:Nuclear Proteins; D020033:Protein Isoforms; D050797:STAT4 Transcription Factor; C494090:STAT4 protein, human; D014157:Transcription Factors; C507969:UNC13D protein, human; C084108:SMARCA4 protein, human; D004265:DNA Helicases