RESUMO
Inborn errors of T cell development present a pediatric emergency in which timely curative therapy is informed by molecular diagnosis. In 11 affected patients across four consanguineous kindreds, we detected homozygosity for a single deleterious missense variant in the gene NudC domain-containing 3 (NUDCD3). Two infants had severe combined immunodeficiency with the complete absence of T and B cells (T -B- SCID), whereas nine showed classical features of Omenn syndrome (OS). Restricted antigen receptor gene usage by residual T lymphocytes suggested impaired V(D)J recombination. Patient cells showed reduced expression of NUDCD3 protein and diminished ability to support RAG-mediated recombination in vitro, which was associated with pathologic sequestration of RAG1 in the nucleoli. Although impaired V(D)J recombination in a mouse model bearing the homologous variant led to milder immunologic abnormalities, NUDCD3 is absolutely required for healthy T and B cell development in humans.
Assuntos
Imunodeficiência Combinada Severa , Recombinação V(D)J , Humanos , Imunodeficiência Combinada Severa/genética , Imunodeficiência Combinada Severa/imunologia , Animais , Camundongos , Recombinação V(D)J/imunologia , Recombinação V(D)J/genética , Masculino , Feminino , Lactente , Linfócitos B/imunologia , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/imunologia , Linfócitos T/imunologia , Pré-Escolar , Mutação de Sentido IncorretoRESUMO
Neurotrophic keratopathy is a corneal disease characterized by impaired corneal innervation. It can lead to corneal epithelial defects, ulcerations, and perforations. Topical insulin has been shown to be effective in treating this disorder. Insulin is a growth factor that can promote corneal epithelial cell proliferation and migration. In addition, it can also inhibit corneal epithelial cell apoptosis. Topical insulin has previously been found to enhance corneal wound healing. This article reviews the current understanding of the mechanism of action of topical insulin in the treatment of neurotrophic keratopathy.