Bronchial Lymphoepithelial Nodules in the Rat

Abstract

Using morphologic and ultrastructural criteria, the present study in the rat was undertaken to distinguish lymphoepithelial modules from lymphoid aggregates and lymph modes, and to demonstrate the uptake and transport of ferritin and latex particles, instilled in the trachea, by the lymphoepithelium. Unlike lymph nodes or lymphoid aggregates, lymphoepithelial nodules can be distinguished by the following characteristics of the lymphoepithelium: it is flattened and devoid of goblet cells; it contains intracellular and "intercellular" vacuoles; occasional macrophage-like cells infiltrates and surrounding lymphocytes clusters can be observed. At any time, no latex particle was found inside or under the lymphoepithelium, but until 1 hour after local instillation, ferritin particles were localized close to the cilia, at the luminal surface of the epithelium, within vesicles at the surface of some cells, and in the intercellular space. Moreover, ferritin particles were consistently present on both sides of the basement membrane after 1 hour. These results suggest that lymphoepithelial nodules may be considered as original structures capable of uptake and transport across the basement membrane of certain foreign materials.

Histological Changes in Rat Bronchus-Associated Lymphoid Tissue after Administration of Five Different Antigens

“…The morphology of bronchus-asso ciated lymphoid tissue (BALT) has been studied in several animals [Bienenslock et al, 1973a;Bienenslock and Johnston, 1976] including the rat [Chamberlain et al, 1973;Vaiet al, 1976;Fournier et al, 1977;Gregson et al, 1979a;Plesch, 1982;Plesch et al, 1983]. The BALT consists of a net-work of reticulum cells in which lympho cytes and macrophages are situated.…”

Structure and Probable Functional Role of the Nasopharyngeal Lymphoepithelial Tissue of the Mouse

“…The epithelium in the nasopharyngeal lymphoepithelial tissue, the so-called "lymphoepithelium (Jolly, 1914)", was heavily infiltrated with lymphoid cells and could not be established its deep border. This type of epithelium has been observed in the lymphoepithelial tissues from different anatomical sites, such as the pharyngeal tonsil (Leela and Kanagasuntheram, 1973), palatine tonsil (Fioretti, 1961;Kawaguchi, 1967;Takagi and Saito, 1974a, b;Saito, 1976), lingual tonsil (Nair and Rossinsky, 1984), bronchus-associated lymphoid tissue (Bienenstock and Johnston, 1976;Fournier et , al., 1977), Peyer's patches (Owen and Jones, 1974;Smith and Peacock, 1980) and appendix (Bockman et al, 1975), and Fioretti (1961) termed i as the "Lymphoepitheliale Symbiose".The lymphoepithelium is not regarded as a pathological state such as infection but as a physiological phenomenon in view of the constancy which it is observed (Takagi and Saito, 1974b;Fournier et al, 1977;Howie, 1981). It is suggested that the epithelial cells and the lymphoid cells coexist within the lymphoepithelium with maintaining any physiological relationships, and play an important role as the first level of the defense mechanism in the lymphoepithelial tissue.…”

Postnatal Development of Bronchus-Associated Lymphoid Tissue (Balt) in the Rat, Rattus Norvegicus

“…One must assume that the differences lie in the degree of antigenic exposure and to interspecies or interstrain differences. Fournier, Vai, Devenne & Pariente (1977) tried to distinguish between lymphoepithelial nodules and lymphoid cell 'clusters', but the results presented above lead to the conclusion that these structures are merely dilTerent developmental stages of the same entity (BALT), and that subclassifications of BAL Tare perhaps unnecessary complications.…”