ABSTRACT
Circulating malignant Sezary cells are a clonal proliferation of CD4+CD45RO+ T lymphocytes primarily involving the skin. To study the biology of these malignant T lymphocytes, we tested their ability to migrate in chemotaxis assays. Previously, we had shown that the neuropeptide neurotensin (NT) binds to freshly isolated Sezary malignant cells and induces through NT1 receptors the cell migration of the cutaneous T cell lymphoma cell line Cou-L. Here, we report that peripheral blood Sezary cells as well as the Sezary cell line Pno fail to migrate in response to neurotensin although they are capable of migrating to the chemokine stromal-cell-derived factor 1 alpha. This is in contrast with normal circulating CD4+ or CD8+ lymphocytes, which respond to both types of chemoattractants except after ex vivo short-time anti-CD3 monoclonal antibody activation, which abrogates the neurotensin-induced lymphocyte migration. Furthermore, we demonstrate that neurotensin-responsive T lymphocytes express the functional NT1 receptor responsible for chemotaxis. In these cells, but not in Sezary cells, neurotensin induces recruitment of phosphatidylinositol-3 kinase, and redistribution of phosphorylated cytoplasmic tyrosine kinase focal adhesion kinase and filamentous actin. Taken together, these results, which show functional distinctions between normal circulating lymphocytes and Sezary syndrome cells, contribute to further understanding of the physiopathology of these atypical cells.
Subject(s)
CD4-Positive T-Lymphocytes/cytology , Chemotaxis/immunology , Receptors, Neurokinin-1/metabolism , Sezary Syndrome/immunology , Sezary Syndrome/pathology , Actins/metabolism , CD4-Positive T-Lymphocytes/immunology , CD4-Positive T-Lymphocytes/metabolism , Enzyme Inhibitors/pharmacology , Focal Adhesion Kinase 1 , Focal Adhesion Protein-Tyrosine Kinases , Gene Expression/immunology , Humans , Jurkat Cells , Neurokinin-1 Receptor Antagonists , Neurotensin/pharmacology , Phosphatidylinositol 3-Kinases/metabolism , Phosphoinositide-3 Kinase Inhibitors , Phosphorylation , Protein-Tyrosine Kinases/metabolism , Pyrazoles/pharmacology , Quinolines/pharmacology , Receptors, Neurokinin-1/geneticsABSTRACT
BACKGROUND: The incidence of skin carcinomas in organ-transplant recipients is high. The main factors implicated in carcinogenesis are immune suppression and ultraviolet radiation. Only the second is avoidable. We have evaluated knowledge of and compliance with sun protection measures among renal-transplant recipients (RTR). METHODS: A survey by means of a questionnaire including questions about clinical data, knowledge of, and compliance with sun protection was given. The questionnaire was given to 520 consecutive RTR followed up in a single center, and 445 (86%) answered. RESULTS: Of the responders, 91% have been informed of the need for sun protection, in 80% of cases by dermatologists. Sixty-eight percent used more protective measures abroad than at home, 63% avoided going outside during the hottest midday hours, 63% used sunscreen regularly, but 46% used one or less tube of sunscreen a year. A hat was always worn in the sun by 35% and long sleeves by 36%. Women and fair-skinned individuals complied better with protective measures. A minority of patients knew that ultraviolet radiation carries a risk of skin cancer. CONCLUSIONS: This survey shows that most RTR are aware of the need for sun protection, but only a minority take adequate protection measures. The better results observed in this study than in previous published investigations may be caused by the great involvement of dermatologists in the care of RTR in our institution. The results of this survey underline the need to inform RTR better about sun-protection measures and the importance of cooperation between transplant physicians and dermatologists.