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Tuovinen EA, Grönholm J, Öhman T, Pöysti S, Toivonen R, Kreutzman A, Heiskanen K, Trotta L, Toiviainen-Salo S, Routes JM, Verbsky J, Mustjoki S, Saarela J, Kere J, Varjosalo M, Hänninen A, Seppänen MRJ. Novel Hemizygous IL2RG p.(Pro58Ser) Mutation Impairs IL-2 Receptor Complex Expression on Lymphocytes Causing X-Linked Combined Immunodeficiency. J Clin Immunol 2020; 40:503-514. [PMID: 32072341 PMCID: PMC7142052 DOI: 10.1007/s10875-020-00745-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 01/06/2020] [Indexed: 11/30/2022]
Abstract
Hypomorphic IL2RG mutations may lead to milder phenotypes than X-SCID, named variably as atypical X-SCID or X-CID. We report an 11-year-old boy with a novel c. 172C>T;p.(Pro58Ser) mutation in IL2RG, presenting with atypical X-SCID phenotype. We also review the growing number of hypomorphic IL2RG mutations causing atypical X-SCID. We studied the patient's clinical phenotype, B, T, NK, and dendritic cell phenotypes, IL2RG and CD25 cell surface expression, and IL-2 target gene expression, STAT tyrosine phosphorylation, PBMC proliferation, and blast formation in response to IL-2 stimulation, as well as protein-protein interactions of the mutated IL2RG by BioID proximity labeling. The patient suffered from recurrent upper and lower respiratory tract infections, bronchiectasis, and reactive arthritis. His total lymphocyte counts have remained normal despite skewed T and B cells subpopulations, with very low numbers of plasmacytoid dendritic cells. Surface expression of IL2RG was reduced on his lymphocytes. This led to impaired STAT tyrosine phosphorylation in response to IL-2 and IL-21, reduced expression of IL-2 target genes in patient CD4+ T cells, and reduced cell proliferation in response to IL-2 stimulation. BioID proximity labeling showed aberrant interactions between mutated IL2RG and ER/Golgi proteins causing mislocalization of the mutated IL2RG to the ER/Golgi interface. In conclusion, IL2RG p.(Pro58Ser) causes X-CID. Failure of IL2RG plasma membrane targeting may lead to atypical X-SCID. We further identified another carrier of this mutation from newborn SCID screening, lost to closer scrutiny.
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Affiliation(s)
- Elina A Tuovinen
- Folkhälsan Research Center, Helsinki, Finland.,Translational Immunology Research Program, University of Helsinki, Helsinki, Finland.,Rare Diseases Center and Pediatric Research Center, New Children's Hospital, University of Helsinki and HUS Helsinki University Hospital, Helsinki, Finland
| | - Juha Grönholm
- Translational Immunology Research Program, University of Helsinki, Helsinki, Finland. .,Rare Diseases Center and Pediatric Research Center, New Children's Hospital, University of Helsinki and HUS Helsinki University Hospital, Helsinki, Finland.
| | - Tiina Öhman
- Systems Biology Research Group and Proteomics Unit, Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Sakari Pöysti
- Department of Clinical Microbiology and Immunology, Turku University Hospital and Institute of Biomedicine, University of Turku, Turku, Finland
| | - Raine Toivonen
- Department of Clinical Microbiology and Immunology, Turku University Hospital and Institute of Biomedicine, University of Turku, Turku, Finland
| | - Anna Kreutzman
- Translational Immunology Research Program, University of Helsinki, Helsinki, Finland.,Hematology Research Unit Helsinki, Helsinki University Hospital Comprehensive Cancer Center, Helsinki, Finland
| | - Kaarina Heiskanen
- Rare Diseases Center and Pediatric Research Center, New Children's Hospital, University of Helsinki and HUS Helsinki University Hospital, Helsinki, Finland
| | - Luca Trotta
- Institute for Molecular Medicine Finland, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Sanna Toiviainen-Salo
- Department of Pediatric Radiology, HUS Medical Imaging Center, Radiology, University of Helsinki and HUS Helsinki University Hospital, Helsinki, Finland
| | - John M Routes
- Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI, USA
| | - James Verbsky
- Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Satu Mustjoki
- Translational Immunology Research Program, University of Helsinki, Helsinki, Finland.,Hematology Research Unit Helsinki, Helsinki University Hospital Comprehensive Cancer Center, Helsinki, Finland.,Department of Clinical Chemistry and Hematology, University of Helsinki, Helsinki, Finland
| | - Janna Saarela
- Institute for Molecular Medicine Finland, HiLIFE, University of Helsinki, Helsinki, Finland.,Department of Medical Genetics, Helsinki Central University Hospital, Helsinki, Finland.,Centre for Molecular Medicine Norway, University of Oslo, Oslo, Norway
| | - Juha Kere
- Folkhälsan Research Center, Helsinki, Finland.,Department of Biosciences and Nutrition, Karolinska Institutet, Stockholm, Sweden.,Stem Cells and Metabolism Research Program, University of Helsinki, Helsinki, Finland
| | - Markku Varjosalo
- Systems Biology Research Group and Proteomics Unit, Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Arno Hänninen
- Department of Clinical Microbiology and Immunology, Turku University Hospital and Institute of Biomedicine, University of Turku, Turku, Finland
| | - Mikko R J Seppänen
- Translational Immunology Research Program, University of Helsinki, Helsinki, Finland.,Rare Diseases Center and Pediatric Research Center, New Children's Hospital, University of Helsinki and HUS Helsinki University Hospital, Helsinki, Finland
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