Identification of checkpoints in human T-cell development using severe combined immunodeficiency stem cells

• Published in: Journal of allergy and clinical immunology Vol. 137; no. 2; pp. 517 - 526.e3
• Main Authors: Wiekmeijer, Anna-Sophia, Pike-Overzet, Karin, IJspeert, Hanna, Brugman, Martijn H., Wolvers-Tettero, Ingrid L.M., Lankester, Arjan C., Bredius, Robbert G.M., van Dongen, Jacques J.M., Fibbe, Willem E., Langerak, Anton W., van der Burg, Mirjam, Staal, Frank J.T.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.02.2016; Elsevier Limited
• Subjects: adenosine deaminase; Allergy and Immunology; Animals; Antigens, Surface - metabolism; Artemis; B-cell development; B-Lymphocytes - cytology; B-Lymphocytes - metabolism; Bone marrow; Cell Differentiation - genetics; Cell Differentiation - immunology; Deoxyribonucleic acid; DNA; Female; Flow cytometry; Gene expression; Gene Rearrangement; Growth factors; Hematopoietic Stem Cell Transplantation; Hematopoietic Stem Cells - cytology; Heterografts; Human subjects; Humans; IL2RG; IL7RA; Immunoglobulin Heavy Chains - genetics; Immunophenotyping; Kinases; Lymphocytes; Lymphoid Progenitor Cells - cytology; Lymphoid Progenitor Cells - metabolism; Mice; Mice, Inbred NOD; Mice, Transgenic; Mutation; NSG; Pediatrics; Phenols; Phenotype; R&D; Receptors, Antigen, T-Cell - genetics; Receptors, Antigen, T-Cell - metabolism; Research & development; SCID; Severe Combined Immunodeficiency - etiology; Stem cells; Stem Cells - cytology; Stem Cells - metabolism; T cell receptors; T-cell development; T-Lymphocytes - cytology; T-Lymphocytes - metabolism; thymus; Thymus Gland - embryology; thymus; TCR; NSG; TRD; DN; IL7RA; BM; IGH; IL2RG; T-cell development; SCID; IMDM; B-cell development; UCB; adenosine deaminase; Artemis; LUMC; NK; ADA; HSPC; Severe combined immunodeficiency; Umbilical cord blood; IL-7 receptor α; T-cell receptor δ; T-cell receptor; Bone marrow; NOD- Scid- Il2rg; Immunoglobulin heavy chain; IL-2 receptor γ; Leiden University Medical Center; Natural killer; Double negative; Iscove modified Dulbecco medium; Hematopoietic stem and progenitor cell
• ISSN: 0091-6749; 1097-6825; 1097-6825
• DOI: 10.1016/j.jaci.2015.08.022

Severe combined immunodeficiency (SCID) represents congenital disorders characterized by a deficiency of T cells caused by arrested development in the thymus. Yet the nature of these developmental blocks has remained elusive because of the difficulty of taking thymic biopsy specimens from affected children. We sought to identify the stages of arrest in human T-cell development caused by various major types of SCID. We performed transplantation of SCID CD34+ bone marrow stem/progenitor cells into an optimized NSG xenograft mouse model, followed by detailed phenotypic and molecular characterization using flow cytometry, immunoglobulin and T-cell receptor spectratyping, and deep sequencing of immunoglobulin heavy chain (IGH) and T-cell receptor δ (TRD) loci. Arrests in T-cell development caused by mutations in IL-7 receptor α (IL7RA) and IL-2 receptor γ (IL2RG) were observed at the most immature thymocytes much earlier than expected based on gene expression profiling of human thymocyte subsets and studies with corresponding mouse mutants. T-cell receptor rearrangements were functionally required at the CD4−CD8−CD7+CD5+ stage given the developmental block and extent of rearrangements in mice transplanted with Artemis-SCID cells. The xenograft model used is not informative for adenosine deaminase–SCID, whereas hypomorphic mutations lead to less severe arrests in development. Transplanting CD34+ stem cells from patients with SCID into a xenograft mouse model provides previously unattainable insight into human T-cell development and functionally identifies the arrest in thymic development caused by several SCID mutations.