title: Ultrastructural localization of alpha-naphthyl acid esterase in human TM lymphocytes.
abstract: The localization of alpha-naphthyl acid esterase (ANAE) activity in T lymphocytes with receptors for IgM (T(M) cells) have been studied at the electron microscope. The electron-opaque product of the cytochemical reaction was detected around, but never inside, single (or groups of) vesicles, which suggested a possible membrane localization of the enzyme activity. These same vesicles were found to contain acid phosphatase by both light- and electron-microscopic examination and were bound by unit membranes; this data indicates that they likely represent primary lysosomes. The presence of such lysosomes in a restricted paranuclear area is a distinctive feature of T(M) cells.
mesh_terms: D000135:Acid Phosphatase / Q000378:metabolism; D001665:Binding Sites; D002265:Carboxylic Ester Hydrolases / Q000378:metabolism*; D006801:Humans; D007075:Immunoglobulin M; D066298:In Vitro Techniques; D008247:Lysosomes / Q000201:enzymology / Q000648:ultrastructure; D008854:Microscopy, Electron; D009283:Naphthol AS D Esterase / Q000378:metabolism*; D011971:Receptors, Immunologic; D013601:T-Lymphocytes / Q000201:enzymology* / Q000648:ultrastructure
chemical_list: D007075:Immunoglobulin M; D011971:Receptors, Immunologic; D009283:Naphthol AS D Esterase; D002265:Carboxylic Ester Hydrolases; D000135:Acid Phosphatase