FLT3L governs the development of partially overlapping hematopoietic lineages in humans and mice

Cell. 2024 May 23;187(11):2817-2837.e31. doi: 10.1016/j.cell.2024.04.009. Epub 2024 May 3.

Abstract

FMS-related tyrosine kinase 3 ligand (FLT3L), encoded by FLT3LG, is a hematopoietic factor essential for the development of natural killer (NK) cells, B cells, and dendritic cells (DCs) in mice. We describe three humans homozygous for a loss-of-function FLT3LG variant with a history of various recurrent infections, including severe cutaneous warts. The patients' bone marrow (BM) was hypoplastic, with low levels of hematopoietic progenitors, particularly myeloid and B cell precursors. Counts of B cells, monocytes, and DCs were low in the patients' blood, whereas the other blood subsets, including NK cells, were affected only moderately, if at all. The patients had normal counts of Langerhans cells (LCs) and dermal macrophages in the skin but lacked dermal DCs. Thus, FLT3L is required for B cell and DC development in mice and humans. However, unlike its murine counterpart, human FLT3L is required for the development of monocytes but not NK cells.

Keywords: B cells; FLT3; FLT3L; FLT3LG; NK cells; dendritic cells; hematopoiesis; human; papillomavirus; primary immunodeficiency.

MeSH terms

  • Animals
  • B-Lymphocytes / cytology
  • B-Lymphocytes / metabolism
  • Bone Marrow / metabolism
  • Cell Lineage
  • Dendritic Cells / metabolism
  • Female
  • Hematopoiesis
  • Hematopoietic Stem Cells / cytology
  • Hematopoietic Stem Cells / metabolism
  • Humans
  • Killer Cells, Natural* / immunology
  • Killer Cells, Natural* / metabolism
  • Langerhans Cells / metabolism
  • Male
  • Membrane Proteins* / genetics
  • Membrane Proteins* / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Monocytes / metabolism
  • Skin / metabolism

Substances

  • flt3 ligand protein
  • Membrane Proteins