title: T-cell receptor analysis in Omenn's syndrome: evidence for defects in gene rearrangement and assembly.
abstract: Patients with Omenn's syndrome have a form of severe immune deficiency that is associated with pathological features of graft-versus-host disease, except for the lack of foreign engraftment. It has been hypothesized that the disease's unique clinical features are mediated by an expanded population of autologous self-reactive T cells of limited clonality. In the current study, an investigation of the T-cell receptor (TCR) repertoire was undertaken to identify defects in T-cell rearrangement and development. The TCR repertoire in this group of patients was exquisitely restricted in the number of different TCR clonotypes, and some of these clonotypes seemed to have similar recognition motifs in the antigen-binding region, indicating antigen-driven proliferation of T lymphocytes. The TCRs from some patients lacked N- or P-nucleotide insertions and used proximal variable and joining gene segments, suggesting abnormal intrathymic T-cell development. Finally, abnormal assembly of gene segments and truncated rearrangements within nonproductive alleles suggested abnormalities in TCR rearrangement mechanisms. Overall, the findings suggest that inefficient and/or abnormal generation of TCRs may be a consistent feature of this disease.
authors.affiliation: University of Texas Medical Branch, Department of Pediatrics, Child Health Research Center, Galveston, TX 77555-0366, USA. ebrooks@utmb.edu
authors.forename: E G
authors.initials: EG
authors.lastname: Brooks
authors.forename: A H
authors.initials: AH
authors.lastname: Filipovich
authors.forename: J W
authors.initials: JW
authors.lastname: Padgett
authors.forename: R
authors.initials: R
authors.lastname: Mamlock
authors.forename: R M
authors.initials: RM
authors.lastname: Goldblum
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D002892:Chromosomes, Human, Pair 22 / Q000235:genetics; D004062:DiGeorge Syndrome / Q000235:genetics / Q000276:immunology; D005260:Female; D015329:Gene Rearrangement, T-Lymphocyte; D015332:Gene Rearrangement, alpha-Chain T-Cell Antigen Receptor; D015333:Gene Rearrangement, beta-Chain T-Cell Antigen Receptor; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008969:Molecular Sequence Data; D011948:Receptors, Antigen, T-Cell / Q000032:analysis* / Q000235:genetics*; D016511:Severe Combined Immunodeficiency / Q000235:genetics* / Q000276:immunology*; D013577:Syndrome; D014158:Transcription, Genetic
chemical_list: D011948:Receptors, Antigen, T-Cell