학술논문

Constrained chromatin accessibility in PU.1-mutated agammaglobulinemia patients
Document Type
article
Source
Journal of Experimental Medicine. 218(7)
Subject
Human Genome
Clinical Research
Stem Cell Research - Nonembryonic - Human
Biotechnology
Regenerative Medicine
Genetics
Stem Cell Research
Stem Cell Research - Nonembryonic - Non-Human
Hematology
Adolescent
Adult
Agammaglobulinemia
B-Lymphocytes
Cell Differentiation
Cell Line
Child
Child
Preschool
Chromatin
Dendritic Cells
Female
Gene Expression Regulation
Developmental
HEK293 Cells
Hematopoiesis
Hematopoietic Stem Cells
Humans
Infant
Lymphopoiesis
Male
Mutation
Precursor Cells
B-Lymphoid
Proto-Oncogene Proteins
Stem Cells
Trans-Activators
Young Adult
Medical and Health Sciences
Immunology
Language
Abstract
The pioneer transcription factor (TF) PU.1 controls hematopoietic cell fate by decompacting stem cell heterochromatin and allowing nonpioneer TFs to enter otherwise inaccessible genomic sites. PU.1 deficiency fatally arrests lymphopoiesis and myelopoiesis in mice, but human congenital PU.1 disorders have not previously been described. We studied six unrelated agammaglobulinemic patients, each harboring a heterozygous mutation (four de novo, two unphased) of SPI1, the gene encoding PU.1. Affected patients lacked circulating B cells and possessed few conventional dendritic cells. Introducing disease-similar SPI1 mutations into human hematopoietic stem and progenitor cells impaired early in vitro B cell and myeloid cell differentiation. Patient SPI1 mutations encoded destabilized PU.1 proteins unable to nuclear localize or bind target DNA. In PU.1-haploinsufficient pro-B cell lines, euchromatin was less accessible to nonpioneer TFs critical for B cell development, and gene expression patterns associated with the pro- to pre-B cell transition were undermined. Our findings molecularly describe a novel form of agammaglobulinemia and underscore PU.1's critical, dose-dependent role as a hematopoietic euchromatin gatekeeper.