title: The fine structure of normal lymphocyte subpopulations--a study with monoclonal antibodies and the immunogold technique.
abstract: The ultrastructural characteristics of normal lymphocyte subpopulations, identified by monoclonal antibodies and visualized by a colloidal gold labelled anti-mouse IgG were analysed. Our study demonstrates: (1) the major T lymphocyte subsets (OKT4+ and OKT8+) have distinct ultrastructural morphology. The majority of OKT4+ cells have a high nuclear/cytoplasmic ratio (N/C) and few cytoplasmic organelles whilst most OKT8+ cells have a low N/C ratio and numerous organelles, namely a well developed Golgi apparatus, lysosomal granules and parallel tubular arrays (PTA); (2) a unique subtype with irregular nuclear outline that resembles Sézary cells was seen in 5-10% of OKT4+ lymphocytes; (3) OKM1, a reagent that reacts with monocytes and granulocytes, is positive in a small lymphocyte subset which appears to be negative with the OKT reagents and is morphologically identical to OKT8+ cells; (4) 'hand-mirror' cells were only seen labelled with OKT8 and OKM1; (5) B lymphocytes labelled with FMC4 (anti-IA) could be distinguished from OKT3+ lymphocytes by having numerous profiles of endoplasmic reticulum (ER) and ribosomes; these were particularly prominent in lymphoplasmacytoid cells. Morphological similarities between normal T lymphocyte subsets and T neoplasias of the same membrane phenotype suggest that these disorders arise from specific T cell types present in normal peripheral blood or from common precursors.
mesh_terms: D000888:Antibodies, Anti-Idiotypic / Q000276:immunology; D000911:Antibodies, Monoclonal / Q000276:immunology; D002467:Cell Nucleus / Q000648:ultrastructure; D002843:Chromatin / Q000648:ultrastructure; D004721:Endoplasmic Reticulum / Q000648:ultrastructure; D006046:Gold / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D008214:Lymphocytes / Q000276:immunology / Q000648:ultrastructure*; D008854:Microscopy, Electron; D013194:Staining and Labeling; D013601:T-Lymphocytes / Q000648:ultrastructure
chemical_list: D000888:Antibodies, Anti-Idiotypic; D000911:Antibodies, Monoclonal; D002843:Chromatin; D007074:Immunoglobulin G; D006046:Gold