title: The distribution of lymphocyte subpopulations in normal and acanthotic ovine skin.
abstract: The prevalence and distribution of lymphocyte subpopulations in normal and acanthotic ovine skin were investigated using monoclonal antibody immunocytochemistry. CD8+ cells were predominant in the epidermis of both normal and acanthotic skin, but were CD8+ cells, CD4+ cells and T19+ cells infrequent in normal epidermis. Within the dermis of normal skin, there were significantly greater numbers of CD4+ and T19+ cells situated around the superficial dermal vessels than in any other region examined. The majority of the CD8+ cells adjoined vessels, but the proportion that did not was greater for CD8+ than for CD4+ or T19+ cells. The CD4+ and CD8+ subsets were represented equally in adnexa. T cells were of memory phenotype. B cells and naive T cells, both of which express the CD45RA antigen, were rarely seen and tended to be associated with vessels in both normal and acanthotic skin. None of the T19+ cells (which are gamma delta+) resembled the dendritic gamma delta cells seen in murine epidermis. Acanthotic skin was strikingly different to normal skin. There was a greater abundance of T cells, particularly CD4+ cells, in acanthotic epidermis and the numbers of CD8+ and T19+ cells, and to a greater extent CD4+ cells, were greater at the dermal-epidermal junction. There were more CD4+ and CD8+ cells in the superficial dermal stroma of acanthotic skin. Within the dermis of acanthotic skin, T cells were concentrated near vessels but the apportioning of T cells between stromal/adnexal and vessel-associated sites differed from normal. Such observations suggest that migration away from perivascular sites and into the stroma may be controlled separately for subregions of skin and for each T cell subset. The role of this altered nonrandom migration of T cells in skin chronically exposed to ultra violet radiation is uncertain.
authors.affiliation: Centre for Animal Biotechnology, University of Melbourne, Parkville, Vic., Australia.
authors.forename: M D
authors.initials: MD
authors.lastname: Gorrell
authors.forename: W L
authors.initials: WL
authors.lastname: Townsend
authors.forename: P W
authors.initials: PW
authors.lastname: Ladds
mesh_terms: D000051:Acantholysis / Q000276:immunology / Q000473:pathology / Q000662:veterinary*; D000818:Animals; D016516:CD4-CD8 Ratio; D016131:Lymphocyte Subsets / Q000276:immunology* / Q000473:pathology; D012756:Sheep; D012757:Sheep Diseases / Q000276:immunology* / Q000473:pathology