Immunohistochemical characterization of nurse cells in normal human thymus (original) (raw)
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Clinical & Developmental Immunology, 1993
Thymic nurse cells (TNC), multiceIlular complexes consisting of lymphoid cells enclosed within cortical epithelial cells, were isolated from mouse thymus by a modified procedure allowing immunofluorescent labeling and flow cytometric analysis of their lymphoid contents (TNC-L). Collagenase was the only protease used for tissue digestion, to ensure that surface antigen markers remained intact. Zonal unit-gravity elutriation was used to enrich the TNC on the basis of their high sedimentation rate, followed by immunomagnetic bead depletion to remove residual mononuclear cell contaminants and a density separation to remove debris. The TNC-L were then released from inside TNC by a short period of culture. The measured contamination of TNC-L with exogenous thymocytes was around 0.5%. Three-color immunofluorescent labeling revealed that TNC-L included, as well as a maiority of immature CD4+8+3 lw thymocytes, hlgn high about 12% of apparently mature CD4 8-3 and CD4-8 3 thymocytes. TNC are located in the cortex, where mature cells are rare; the occurrence of mature phenotype cells within these structures suggests that they represent a microenvironment for the selection and generation of mature T cells.
Biological Research, 2010
Thymulin is a well-characterized thymic hormone that exists as a nonapeptide coupled to equimolar amounts of Zn 2+. Thymulin is known to have multiple biological roles, including T cell differentiation, immune regulation, and analgesic functions. It has been shown that thymulin is produced by the reticulo-epithelial cells of the thymus, and it circulates in the blood from the moment of birth, maintain its serum level until puberty diminishing thereafter in life. To study the localization of this hormone, we prepared polyclonal and monoclonal antibodies against the commercial peptide and utilized immunocytochemical techniques for visualization. The results indicate that thymulin stains the thymic reticular cells, the outer layers of Hassall´s corpuscles and a large round cellular type, which is keratin-negative and does not show affinity for the common leukocyte antigen (CD-45). In mice, this thymulin-positive cell remains in the thymus throughout life and even appears in relatively increased numbers in old involuted thymi. It also appears in thymusdependent areas of the spleen and lymph nodes, demonstrating that at least one of the thymus cells containing this peptide can be found in peripheral lymphoid tissue.
Developmental Immunology, 2002
In this work, the interaction between a rat cortical thymic epithelial cell (TEC) line (R-TNC.1) with nursing activity and thymocytes as well as BWRT 8 thymocyte hybridoma (TH) cells has been studied. The R-TNC.1 cell line significantly bound thymocytes and TH. Binding was stronger during the first 30 min of cell incubation and was followed by a progressive deadhesion. Among adherent thymocytes the proportion of apoptotic cells increased with culture time which was a consequence of higher capacity of the line for binding of apoptotic than viable cells and induction of apoptosis in a subset of adherent thymocytes. Emperiopolesis activity of this thymic nurse cell (TNC) line was manifested by engulfment of thymocytes as well as TH cells. A subset of viable intra-TNC thymocytes has been triggered to die by apoptosis, whereas other internalized thymocytes have been stimulated to proliferate, as measured by an increase in the percentage of cells in mitosis and higher incorporation of bro...
Immunohistological evidences of cortical and medullary differentiation in thymoma
Virchows Archiv, 1985
The phenotypical characteristics of human epithelial and lymphoid cells have been studied with immunohistochemical methods on frozen sections of 12 thymomas. On the basis of the cytohistological characteristics of thymoma epithelial cells (EC) the thymomas were divided in cortical, medullary and mixed types, according to recently developed light microscopical criteria. When tested with a series of monoclonal antibodies, thymoma EC were all stained by the antibody Ki-M3 (as in the thymus), but reacted with anti-HLA-DR, anti-HLA-A,B,C and with a new monoclonal antibody to cortical EC,21A6, to a lesser extent and with weaker, variable intensity in comparison with the normal thymus. Cortical type thymomas were most reactive and the medullary type almost negative. Thymomas, like normal thymus showed different immunoreactivity patterns with antibodies to prekeratins of different specificities. Cortical type thymomas and areas in mixed thymoma showed an EC staining with the antibody to non-squamous type keratin (35βH11) whereas medullary type thymomas and areas showed staining with antibodies to squamous-type keratin (34βE12-IV/82) in addition. Lymphoidcellswithcortical(OKT6+,Leu 1 weakly+,Leu2a+,Leu3a+) or mature medullary (OKT6-, Leu 1 strongly+, Leu 2a or Leu 3a+) phenotype were found to colonize tumours with diferent EC types. These immunohistochemical findings largely confirm our earlier cytological distinction of thymoma EC. In addition important differences have been observed in neoplastic cortical EC concerning the HLA-DR and 21A6 immunoreactivity that may be intimately related to the neoplastic process and paraneoplastic immune phenomena.
Cellular Immunology, 2004
Much debate has been generated about the existence of thymic nurse cells within the thymus. Until now, the authenticity of an epithelial cell capable of internalizing developing thymocytes within the thymic cortex has been in question. Here, we use the thymic nurse cell-speciWc monoclonal antibody, ph91, to deWne the in vivo location of thymic nurse cells. For the Wrst time, thymic nurse cells enclosing several thymocytes were detected in the subcapsular region of the thymic cortex in a "honeycomb-like" conWguration. In vitro studies show the internalization process using digitalized time-lapse microscopy. Internalized thymocytes have also been reported to interact with macrophages within the TNC complex. The cytoplasmic interaction between thymocytes and macrophages was detected using time-lapse microscopy. Using Xuorescence microscopy, we show polymerization of actin within macrophages at the contact point with thymocytes, which is indicative of an immunological synapse. MicroWlaments and microtubules within TNCs were shown to be associated with thymocyte binding and internalization, but neither interacted with macrophages. Also, we provide data to show that thymocytes are actively involved in the internalization process. These experiments show for the Wrst time the existence of thymic nurse cells within the thymic microenvironment. They provide a visual documentation of thymocyte uptake by thymic nurse cells, and deWne an interaction between thymocytes and macrophages within the TNC complex.
Annals of Anatomy - Anatomischer Anzeiger, 2003
We examined the expression of various CD coded or not yet defined antigens in human thymus samples using indirect immunoperoxidase and immunoflourescent techniques. Data obtained are presented in concurrence with Clusters of Thymic Epithelial Staining (CTES) classification for various monoclonal antibodies recognizing CD antigens (CD1, CD165, CD166) and for monoclonal antibodies 1B10, 5G7, A4, BD46, BLTZ, HPIC5, IND.64, M72, WU947 whose specifities are not yet defined. Some of the mAbs such as CD49f, IND.64 and BD46 are detected as good markers for specific cell types or compartments. Significance of the presence of these antigens on thymic epithelial cells at certain locations is briefly discussed.
Thymic Nurse Cells Determined In Situ at the Light and Electron Microscopic Level
Turkish Journal of Veterinary & Animal Sciences, 2002
Thymic nurse cells are isolated thymic epithelial/thymocyte complexes described in vitro. Their in vivo existence is controversial. We examined rat thymi in order to distinguish thymic nurse cells in vivo using the zinc iodide-osmium tetroxide (ZIO) fixation/staining technique. There were mainly two types of strongly ZIO reactive cells in the thymic cortex: macrophages and small clusters of thymic epithelial cells. The latter group was composed of thymic epithelial cells and intact thymocytes forming complexes. Thus we suggest that these structures are in situ equivalents of thymic nurse cells.
Ontogeny of Rat Thymic Epithelium Defined by Monoclonal Anticytokeratin Antibodies
Developmental Immunology, 1990
Ontogenetic study on the expression of cytokeratin (CK) polypeptides within particular subsets of rat thymic epithelial cells (TEC) has been performed by a large panel of anti-CK monoclonal antibodies (mAbs) using the streptavidin-biotin immunoperoxidase method. Simultaneous presence of two or more CK subunits in the same TEC has been demonstrated by double immunoflouorescence labeling. The obtained results showed that the expression of CK polypeptides in fetal and neonatal thymus differed from the adult patterns. The main difference was observed in expression of CK10, 18, and 19 polypeptides. During fetal ontogeny, CK10 and 18 are markers for most medullary TEC or a subset of medullary TEC, respectively, whereas CK19 is mainly a pan-TEC marker. In the adult animals, they are localized in the cortical and a subset of medullary TEC (CK18), subcapsular/perivascular and some medullary TEC (CK19), or in a subset of medullary TEC and Hasall’s corpuscles (HC) (CK10). The switch in their e...