In:
Science Immunology, American Association for the Advancement of Science (AAAS), Vol. 1, No. 6 ( 2016-12-23)
Abstract:
Recombination-activating genes 1 and 2 ( RAG1 and RAG2 ) play a critical role in T and B cell development by initiating the recombination process that controls the expression of T cell receptor (TCR) and immunoglobulin genes. Mutations in the RAG1 and RAG2 genes in humans cause a broad spectrum of phenotypes, including severe combined immunodeficiency (SCID) with lack of T and B cells, Omenn syndrome, leaky SCID, and combined immunodeficiency with granulomas or autoimmunity (CID-G/AI). Using next-generation sequencing, we analyzed the TCR and B cell receptor (BCR) repertoire in 12 patients with RAG mutations presenting with Omenn syndrome ( n = 5), leaky SCID ( n = 3), or CID-G/AI ( n = 4). Restriction of repertoire diversity skewed usage of variable (V), diversity (D), and joining (J) segment genes, and abnormalities of CDR3 length distribution were progressively more prominent in patients with a more severe phenotype. Skewed usage of V, D, and J segment genes was present also within unique sequences, indicating a primary restriction of repertoire. Patients with Omenn syndrome had a high proportion of class-switched immunoglobulin heavy chain transcripts and increased somatic hypermutation rate, suggesting in vivo activation of these B cells. These data provide a framework to better understand the phenotypic heterogeneity of RAG deficiency.
Type of Medium:
Online Resource
ISSN:
2470-9468
DOI:
10.1126/sciimmunol.aah6109
Language:
English
Publisher:
American Association for the Advancement of Science (AAAS)
Publication Date:
2016
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