Langerhans cell (LC) proliferation mediates neonatal development, homeostasis, and inflammation-associated expansion of the epidermal LC network.
Author(s)
Type
Journal Article
Abstract
Most tissues develop from stem cells and precursors that undergo differentiation as their proliferative potential decreases. Mature differentiated cells rarely proliferate and are replaced at the end of their life by new cells derived from precursors. Langerhans cells (LCs) of the epidermis, although of myeloid origin, were shown to renew in tissues independently from the bone marrow, suggesting the existence of a dermal or epidermal progenitor. We investigated the mechanisms involved in LC development and homeostasis. We observed that a single wave of LC precursors was recruited in the epidermis of mice around embryonic day 18 and acquired a dendritic morphology, major histocompatibility complex II, CD11c, and langerin expression immediately after birth. Langerin(+) cells then undergo a massive burst of proliferation between postnatal day 2 (P2) and P7, expanding their numbers by 10-20-fold. After the first week of life, we observed low-level proliferation of langerin(+) cells within the epidermis. However, in a mouse model of atopic dermatitis (AD), a keratinocyte signal triggered increased epidermal LC proliferation. Similar findings were observed in epidermis from human patients with AD. Therefore, proliferation of differentiated resident cells represents an alternative pathway for development in the newborn, homeostasis, and expansion in adults of selected myeloid cell populations such as LCs. This mechanism may be relevant in locations where leukocyte trafficking is limited.
Date Issued
2009-12-21
Start Page
3089
End Page
3100
Journal / Book Title
J Exp Med
Volume
206
Issue
13
Copyright Statement
© 2009 Chorro et al. This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.jem.org/misc/terms.shtml). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 3.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/3.0/).
Identifier
http://www.ncbi.nlm.nih.gov/pubmed/19995948
jem.20091586
Coverage Spatial
United States