Bmi1 Maintains the Self-Renewal Property of Innate-like B Lymphocytes. Academic Article uri icon

Overview

abstract

  • The self-renewal ability is a unique property of fetal-derived innate-like B-1a lymphocytes, which survive and function without being replenished by bone marrow (BM) progenitors. However, the mechanism by which IgM-secreting mature B-1a lymphocytes self-renew is poorly understood. In this study, we showed that Bmi1 was critically involved in this process. Although Bmi1 is considered essential for lymphopoiesis, the number of mature conventional B cells was not altered when Bmi1 was deleted in the B cell lineage. In contrast, the number of peritoneal B-1a cells was significantly reduced. Peritoneal cell transfer assays revealed diminished self-renewal ability of Bmi1-deleted B-1a cells, which was restored by additional deletion of Ink4-Arf, the well-known target of Bmi1 Fetal liver cells with B cell-specific Bmi1 deletion failed to repopulate peritoneal B-1a cells, but not other B-2 lymphocytes after transplantation assays, suggesting that Bmi1 may be involved in the developmental process of B-1 progenitors to mature B-1a cells. Although Bmi1 deletion has also been shown to alter the microenvironment for hematopoietic stem cells, fat-associated lymphoid clusters, the reported niche for B-1a cells, were not impaired in Bmi1 -/- mice. RNA expression profiling suggested lysine demethylase 5B (Kdm5b) as another possible target of Bmi1, which was elevated in Bmi1-/- B-1a cells in a stress setting and might repress B-1a cell proliferation. Our work has indicated that Bmi1 plays pivotal roles in self-renewal and maintenance of fetal-derived B-1a cells.

publication date

  • April 24, 2020

Research

keywords

  • B-Lymphocyte Subsets
  • Polycomb Repressive Complex 1
  • Proto-Oncogene Proteins

Identity

PubMed Central ID

  • PMC7293378

Scopus Document Identifier

  • 85086298798

Digital Object Identifier (DOI)

  • 10.4049/jimmunol.2000030

PubMed ID

  • 32332108

Additional Document Info

volume

  • 204

issue

  • 12