Epithelial Cells: Immunological Aspects

Saveria Pastore, Istituto Dermopatico dell'Immacolata, Roma, Italy
Cristina Albanesi, Istituto Dermopatico dell'Immacolata, Roma, Italy
Giampiero Girolomoni, University of Verona, Verona, Italy

Published online: January 2007

DOI: 10.1002/9780470015902.a0001127

Epithelial cells display their nature of integral, resident components of the innate immune system, and provide a valid defensive line against environmental threats through the expression of a plethora of active mediators, including antimicrobial peptides, cytokines, chemokines and cell membrane molecules. By contrast, epithelial cells can play a relevant role in the pathogenesis of chronic inflammatory disorders (e.g. atopic dermatitis and psoriasis), where the amplification of the inflammatory reactions critically depends on the crosstalk between infiltrating leucocytes and epithelial cells.

Keywords: toll-like receptors; antimicrobial peptides; cytokines; chemokines; keratinocytes

Figure 1. High expression of the neutrophil chemoattractant IL-8 and of the T-cell chemokine IP-10 in the psoriatic lesion. These chemokines cannot be detected in the healthy skin, or in relevant levels in the lesions from atopic dermatitis patients.
Figure 2. Massive CD3+ T cell infiltrate in the upper dermis and at the interface with the epidermis of a psoriatic lesion. In the inset, negative staining of healthy skin control.
Figure 3. Epidermal keratinocytes respond to a variety of exogenous stimuli with the release of a plethora of chemokines and cytokines implicated in the attraction and local activation of immune cells, including polymorphonucleates (PMN), macrophages (M), dendritic cells (DC) and T cells. In turn, the cytokines released at high levels by infiltrating T cells, mainly represented by IFN, TNF, IL-1 and IL-17 are potent activators of keratinocyte pro-inflammatory functions, including the expression of membrane molecules involved in the retention and activation of T cells in the epidermis.
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 Further Reading
    Abreu MT, Fukata M and Arditi M (2005) TLR signaling in the gut in health and disease. Journal of Immunology 174: 4453–4460.
    Braff MH, Bardan A, Nizet V and Gallo RL (2005) Cutaneous defense mechanisms by antimicrobial peptides. Journal of Investigative Dermatology 125: 9–13.
    Esche C, Stellato C and Beck LA (2005) Chemokines: key players in innate and adaptive immunity. Journal of Investigative Dermatology 125: 615–628.
    Ganz T (2003) Defensins: antimicrobial peptides of innate immunity. Nature Reviews in Immunology 3: 710–720.
    book Girolomoni G, Mascia F, Dattilo C, Giannetti A and Pastore S (2006) "Keratinocytes in atopic eczema". In: Ring J, Przybilla B, Ruzicka T (eds) Handbook of Atopic Eczema, pp. 332–339. Berlin, Germany: Springer
    McInturff JE, Modlin RL and Kim J (2005) The role of toll-like receptors in the pathogenesis and treatment of dermatological disease. Journal of Investigative Dermatology 125: 1–8.
    book Pastore S, Cavani A, Albanesi C and Girolomoni G (2005) "Chemokines of human skin". Bos JD (ed.) Skin Immune System. Cutaneous Immunology and Clinical Immunodermatology, pp. 373–392. Boca Raton, FL, USA: CRC Press
    Segre JA (2006) Epidermal barrier formation and recovery in skin disorders. Journal of Clinical Investigation 116: 1150–1158.

Related Sub-Topics:

Inflammation | Innate Immunity | Cells of the Immune System
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Article Title: Epithelial Cells: Immunological Aspects
 
How to Cite close
Pastore, Saveria, Albanesi, Cristina, and Girolomoni, Giampiero(Jan 2007) Epithelial Cells: Immunological Aspects. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1002/9780470015902.a0001127]