Identification of a novel lymphoid population in the murine epidermis

Sci Rep. 2015 Jul 30:5:12554. doi: 10.1038/srep12554.

Abstract

T cell progenitors are known to arise from the foetal liver in embryos and the bone marrow in adults; however different studies have shown that a pool of T cell progenitors may also exist in the periphery. Here, we identified a lymphoid population resembling peripheral T cell progenitors which transiently seed the epidermis during late embryogenesis in both wild-type and T cell-deficient mice. We named these cells ELCs (Epidermal Lymphoid Cells). ELCs expressed Thy1 and CD2, but lacked CD3 and TCRαβ/γδ at their surface, reminiscent of the phenotype of extra- or intra- thymic T cell progenitors. Similarly to Dendritic Epidermal T Cells (DETCs), ELCs were radioresistant and capable of self-renewal. However, despite their progenitor-like phenotype and expression of T cell lineage markers within the population, ELCs did not differentiate into conventional T cells or DETCs in in vitro, ex vivo or in vivo differentiation assays. Finally, we show that ELC expressed NK markers and secreted IFN-γ upon stimulation. Therefore we report the discovery of a unique population of lymphoid cells within the murine epidermis that appears related to NK cells with as-yet-unidentified functions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • CD2 Antigens / metabolism
  • CD3 Complex / metabolism
  • Cell Differentiation
  • Cells, Cultured
  • Coculture Techniques
  • Epidermal Cells
  • Epidermis / metabolism*
  • Homeodomain Proteins / genetics
  • Homeodomain Proteins / metabolism
  • Interferon-gamma / metabolism
  • Interleukin-2 / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Mice, Nude
  • Microscopy, Fluorescence, Multiphoton
  • Phenotype
  • Receptors, Antigen, T-Cell, gamma-delta / metabolism
  • T-Lymphocytes / cytology
  • T-Lymphocytes / immunology
  • Thy-1 Antigens / metabolism

Substances

  • CD2 Antigens
  • CD3 Complex
  • Homeodomain Proteins
  • Interleukin-2
  • Receptors, Antigen, T-Cell, gamma-delta
  • Thy-1 Antigens
  • RAG-1 protein
  • Interferon-gamma