The aim of this work was to study the relationship between UVB and LC by examining the influence of moderate, suberythemal doses of UVB, such as are used to treat psoriasis, on epidermal LC morphology, numbers and surface expression of CD1a and major histocompatibility class II (MHC II) antigens in human skin. A six week course of UVB irradiation, using our standard therapeutic regimen for the treatment of psoriasis (total doses of UVB ranged from 2.58-5.58 J/cm<SUP>2</SUP>), was administered to nine healthy subjects. The morphology and number of LCs, and the distribution and expression of certain LC surface antigens were studied in control and in UVB-irradiated epidermis. The study of LC morphology prior to UVB irradiation, using the technique of confocal laser scanning microscopy, revealed that their dendrites extended mainly in the horizontal plane of the epidermis and dendrite numbers ranged between two and nine per cell. Adjacent LCs were in close apposition, but there was little contact between them The majority of normal unirradiated epidermal LCs expressed HLA-DP, HLA-DQ and HLA-DR antigens, which were demonstrated by quantitative ultrastructural immunogold method using image analysis, although a small proportion either did not express these antigens or expressed them at high surface densities. In conclusion, a true reduction in the number of LCs occurs after UVB exposure which cannot be explained simply by the loss of LC surface antigen expression. These studies have defined the UVB-induced changes in LC morphology, number and antigen expression in normal human skin.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:662314 |
| Date | January 1994 |
| Creators | Spencer, Mary-Jane |
| Publisher | University of Edinburgh |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/1842/20808 |
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