title: Lymphocyte-specific protein 1: a specific marker of human leucocytes.
abstract: While both murine and human homologues of the LSP1 gene (lymphocyte-specific gene 1) and its protein products have been identified, studies on human LSP1 have been limited. The present report describes a detailed immunocytochemical study of the distribution and localization of human LSP1 in both normal and neoplastic cells and tissues. The specificity of the monoclonal anti-LSP1 reagent was confirmed by expression cloning and transfection studies. The intracellular 60 000 MW LSP1 protein was found to be present in peripheral blood B cells, monocytes and granulocytes but absent in a subpopulation of circulating T cells (10-15% of CD3-positive T cells). The presence of LSP1 protein in medullary thymocytes, but only in scattered cortical thymocytes, provided additional evidence for heterogeneity of expression in T cells. Novel observations also included the presence of LSP1 in plasma cells, dendritic cells and Langerhans' cells. The leucocyte-restricted distribution of LSP1 protein means that it may play an important role in haematopathology. LSP1 protein was detected in a wide range of leukaemias and lymphomas, particularly of B-cell origin, and in tumour cells in classical Hodgkin's disease. Of interest was the indication of a reciprocal relationship in the expression of LSP1 and ALK (anaplastic lymphoma kinase) proteins in patients with anaplastic large cell lymphoma. As the anti-LSP1 reagent used in the present study recognizes a formalin-resistant epitope it should be of considerable value in the diagnosis of routinely fixed material.
authors.affiliation: Leukaemia Research Fund Immunodiagnostics Unit, Nuffield Department of Clinical Biochemistry and Cellular Science, John Radcliffe Hospital, Oxford, UK.
authors.forename: K
authors.initials: K
authors.lastname: Pulford
authors.forename: M
authors.initials: M
authors.lastname: Jones
authors.forename: A H
authors.initials: AH
authors.lastname: Banham
authors.forename: E
authors.initials: E
authors.lastname: Haralambieva
authors.forename: D Y
authors.initials: DY
authors.lastname: Mason
mesh_terms: D000077548:Anaplastic Lymphoma Kinase; D001402:B-Lymphocytes / Q000737:chemistry; D015415:Biomarkers / Q000032:analysis; D015153:Blotting, Western; D002460:Cell Line; D003713:Dendritic Cells / Q000737:chemistry; D006098:Granulocytes / Q000737:chemistry; D006689:Hodgkin Disease / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D007801:Langerhans Cells / Q000737:chemistry; D007938:Leukemia / Q000378:metabolism*; D007962:Leukocytes / Q000737:chemistry*; D008223:Lymphoma / Q000737:chemistry*; D016403:Lymphoma, Large B-Cell, Diffuse / Q000737:chemistry; D009000:Monocytes / Q000737:chemistry; D010750:Phosphoproteins / Q000032:analysis*; D010950:Plasma Cells / Q000737:chemistry; D011505:Protein-Tyrosine Kinases / Q000032:analysis; D020794:Receptor Protein-Tyrosine Kinases; D013950:Thymus Gland / Q000737:chemistry
chemical_list: D015415:Biomarkers; D010750:Phosphoproteins; C093915:lymphocyte-specific protein p50; C000626173:ALK protein, human; D000077548:Anaplastic Lymphoma Kinase; D011505:Protein-Tyrosine Kinases; D020794:Receptor Protein-Tyrosine Kinases