口こう内局所免疫機構の免疫組織化学的解析 小だ液せんを中心として

Abstract

To define the mechanism involved in the transport of immunoglobulins into saliva from the minor salivary glands, the authors studied the localization of IgA, IgM, IgG, secretory component (SC) and J chain in the human lip and palatine minor salivary glands by the peroxidase-labeled antibody technique. In addition, the concentration of secretory IgA (s IgA) in non-stimulated whole saliva and serum were evaluated by a column enzyme immunoassay.At the light microscopic level, IgA, IgM, SC and J chain were pominent in the mucous acinar cells and glandular epithelial cells. However, IgG was not detected in these epithelial cells. Immunocytes containing IgA, IgG or IgM were found in the interstitium. At the electronmicroscopic level, SC was localized in the perinuclear spaces, rough endoplasmic reticula, saccules associated with Golgi complexes, cytoplasmic vesicles and secretory granules, and on the lateral and basal plasma membranes of mucous acinar cells and glandular epithelial cells. IgA, IgM and J chain, but not IgG, were also localized on the plasma membranes and in the cytoplasmic vesicles of these cells where SC is located.These findings provide the following evidence.1) The sites of SC synthesis in the minor salivary glands are mucous acinar cells and glandular epithelial cells.2) Polymeric IgA and IgM containing J chain are translocated through these epithelial cells as s IgA by a SC-mediated transport mechanism involving cytoplasmic vesicles.3) Free SC is secreted into saliva through secretory granules in the mucous acinar cells, and also there is a suggestion that they are secreted through cytoplasmic vesicles in these cells.4) IgG does not share the transepithelial cell route with IgA and IgM.5) The slg A levels in whole saliva and serum were 180.6 ± 93 μ g/ml and 8.6 ± 3.7 μ g/ml, respectively.