title: Localization of sialidase-positive cells expressing Mac-1 and immunoglobulin in the mouse thymus.
abstract: We have sought an endogenous membrane bound sialidase acting at neutral pH in immune system, because the removal of sialic acid from cell surfaces will affect the cell-cell interaction directly or indirectly. The levels of activity of unique membrane-bound sialidase at neutral pH and also soluble sialidase are high in the thymus but low in the spleen and lymph nodes. These are thought to be plasma membrane and cytosolic types based on the behavior of inhibition by Cu(2+) and 2-deoxy-2, 3-dehydro-N-acetylneuraminic acid. Newly synthesized 5-bromo-4-chloro-3-indolyl-N-acetylnueraminic acid was used for histochemical staining of sialidase-positive thymic cells, and the results showed positive cells sparsely distributed in the corticomedullar region or medullary region of the thymus. They expressed immunoglobulin and Mac-1 antigen on their surfaces. These cells must therefore be of a B cell lineage, not a T cell lineage. We also found that some vessels in the thymus were sialidase-positive.
authors.affiliation: Institute for Immunological Science/Genetic Medicine, Hokkaido University, N-15, W-7, Sapporo 060-0815, Japan. koshigeko@hkg.odn.ne.jp
authors.forename: Shigeko
authors.initials: S
authors.lastname: Kijimoto-Ochiai
authors.forename: Naoko
authors.initials: N
authors.lastname: Doi
authors.forename: Hiroko
authors.initials: H
authors.lastname: Matsukawa
authors.forename: Miwako
authors.initials: M
authors.lastname: Fujii
authors.forename: Koji
authors.initials: K
authors.lastname: Tomobe
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000378:metabolism; D002450:Cell Communication; D019070:Cell Lineage; D002462:Cell Membrane / Q000378:metabolism; D003300:Copper / Q000737:chemistry; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007136:Immunoglobulins / Q000378:metabolism*; D007150:Immunohistochemistry; D016177:Macrophage-1 Antigen / Q000378:metabolism*; D051379:Mice; D008809:Mice, Inbred C3H; D019158:N-Acetylneuraminic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D009439:Neuraminidase / Q000096:biosynthesis* / Q000378:metabolism; D010710:Phosphates / Q000378:metabolism; D013154:Spleen / Q000378:metabolism; D013601:T-Lymphocytes / Q000378:metabolism; D013950:Thymus Gland / Q000378:metabolism*; D013997:Time Factors
chemical_list: C413308:5-bromo-4-chloro-3-indolyl-N-acetylneuraminic acid; D004791:Enzyme Inhibitors; D007136:Immunoglobulins; D016177:Macrophage-1 Antigen; D010710:Phosphates; C036137:2-deoxy-2,3-dehydro-N-acetylneuraminic acid; D003300:Copper; D009439:Neuraminidase; D019158:N-Acetylneuraminic Acid