Please use this identifier to cite or link to this item: http://hdl.handle.net/11434/595
Title: Evidence that the bulge region is a site of relative immune privilege in human hair follicles.
Epworth Authors: Sinclair, Rodney
Other Authors: Meyer, K. C.
Klatte, J. E.
Dinh, H. V.
Harries, M. J.
Reithmayer, K.
Meyer, W.
Paus, R.
Keywords: Head and Neck Clinical Institute, Epworth HealthCare, Richmond, Victoria, Australia.
Department of Dermatology, Epworth HealthCare, Richmond, Victoria, Australia.
Down-Regulation
Immunology
Hair Follicle
Histocompatibility Antigens Class I
Metabolism
Histocompatibility Antigens Class II
Humans
Immunohistochemistry
Immunosuppressive Agents
Indoleamine-2, 3-Dioxygenase
Interferon-gamma
Pharmacology
Scalp
beta 2-Microglobulin
Macrophage Migration-Inhibitory Factors
Issue Date: Nov-2008
Publisher: Wiley Online Library
Citation: British Journal of Dermatology. 2008 Nov;159(5):1077-85.
Abstract: BACKGROUND: Recent gene profiling data suggest that, besides the anagen hair bulb, the epithelial stem cell region in the outer root sheath of hair follicles (HFs), termed the bulge, may also represent an area of relative immune privilege (IP). OBJECTIVES: To investigate whether the human HF bulge is a site of relative IP within anagen VI HFs. METHODS: Anagen VI HFs from normal human scalp skin were analysed using immunohistological staining techniques, quantitative histomorphometry and statistical analysis. For functional evidence we performed full-thickness human scalp skin organ cultures to investigate whether interferon (IFN)-gamma, a key inducer of IP collapse in hair bulbs, has a similar effect on the putative bulge IP. RESULTS: Major histocompatibility complex (MHC) class Ia, beta(2)-microglobulin and MHC class II immunoreactivity are downregulated in the human bulge. The immunosuppressants alpha-melanocyte stimulating hormone, transforming growth factor-beta2, macrophage migration inhibitory factor and indoleamine-2,3-dioxygenase (IDO) are upregulated in the CD200+, stem cell-rich bulge region. These CD200+ cells also co-express HLA-E. Furthermore, IFN-gamma induces significant ectopic MHC class Ia expression in bulge cells of organ-cultured human scalp skin. CONCLUSIONS: These data suggest that the bulge of human anagen HFs represents a hitherto unrecognized site of relative IP in human skin. Simultaneously, we present the first evidence of IDO and HLA-E protein expression in normal human HFs. Bulge IP presumably protects the HF epithelial stem cell reservoir from autoaggressive immune attack whereas a loss of bulge IP may play a central role in the pathogenesis of cicatricial alopecias.
URI: http://hdl.handle.net/11434/595
DOI: 10.1111/j.1365-2133.2008.08818.x
PubMed URL: http://www.ncbi.nlm.nih.gov/pubmed/18795933
ISSN: 0007-0963
1365-2133
Journal Title: British Journal of Dermatology
Type: Journal Article
Affiliated Organisations: Department of Dermatology, Allergology and Venereology, University of Lübeck, Ratzeburger Allee, Lübeck, Germany.
Type of Clinical Study or Trial: Cohort Study
Appears in Collections:Head & Neck
Dermatology

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