Natural killer cells express the CD16 antigen.
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Antigens, Surface↗
Biomedical subjects
G C Manara
Publications and source records attributed to G C Manara.
Morphometric characterization of NK cell subset expressing the Leu-11 antigen in comparison to Leu-7 positive, 11 negative cells.
Three subpopulations of human natural killer (NK) cells were identified by immunoelectron microscopy, using combinations of anti-Leu-7 and anti-Leu-11 monoclonal antibodies. For each subpopulation the nuclear area/cellular area ratio (An/Ac) and the perimeter/equivalent circumference ratio were evaluated employing an interactive image analyzer. Leu-11+ cells showed a larger area, a smaller An/Ac and a higher "villousity degree" in comparison to Leu-7+, 11- cells. These differences were proved to be significant using the Kolmogorov-Smirnov two sample test. Previous studies described the existence of distinct cytotoxic capability, recombinant interleukin 2-mediated activation, and ultrastructural features of Leu-11+ in comparison to Leu-7+, 11- cells. This is the first report in which morphometric differences within NK cell subsets are exactly determined.
Antibodies, Monoclonal↗
Langerhans cells are not damaged in contact allergic reactions in humans.
Fifteen biopsies from contact allergic reactions in sensitized patients were taken at different time intervals after application of simple chemicals. Two different procedures for electron microscopy were done. No signs of damage were ever seen in Langerhans cells. The authors are therefore of the opinion that there is still no proof for a target role of Langerhans cells in contact allergic reactions in humans.
Cobalt↗
An in situ immunogold method applied to the identification of plasma membrane-associated antigens of skin-infiltrating cells.
This report concerns a pre-embedding in situ double-step immunogold technique to detect cell surface antigens of skin infiltrating cells. Reliable immunogold labeling of cell surface antigens, as well as good ultrastructural preservation of cell and tissue details, were achieved. In comparison with the commonly used method of in situ immunoperoxidase labeling, the present in situ immunogold labeling has some advantages, such as higher specificity, higher sensitivity, and the possibility of estimating the density of the labeling. However, a drawback in the present technique is the compulsory high-magnification analysis of the specimens at the electron microscope, due to the small size of the gold particles.
Antibodies, Monoclonal↗
Immunogold labelling of epidermal Langerhans cells on tissue sections of normal human skin.
A colloidal gold staining procedure was developed for immuno-electron microscopy, which allowed the demonstration of T6 surface antigens of epidermal Langerhans cells on sections of normal human skin with consistent ultrastructural preservation of subcellular structures. All the observed Birbeck granule-bearing Langerhans cells revealed immunogold labelling along the plasma membrane. The penetration of the tissue by the gold particles was adequate, as was the sensitivity and the specificity of the reaction. A major advantage of the present method in comparison with immunoperoxidase techniques is the absence of non-specific staining of the membranes of keratinocytes facing the labelled plasma membrane of the Langerhans cells.
Antibodies, Monoclonal↗
Characterization of two morphologically distinct Leu-7+ cell subsets with respect to Leu-15 antigen. Evaluation of Leu-15 determinant distribution on both E rosetting and non-adherent non-E rosetting cell populations.
In the present study the fine structures of Leu-7+-Leu-15+ and Leu-7+-Leu-15- cell subpopulations were characterized by using an immunogold-immunoperoxidase double labelling in electron microscopy. The densities of Leu-15 antigenic sites on both E rosetting (Er) and non-adherent/non-E rosetting (non-A/non-Er) Leu-15 positive cell surfaces were also evaluated by using an immunogold analysis in electron microscopy. A majority of Leu-7+ cells co-expressed the Leu-15 antigen and showed an ultrastructural pattern specific for mature natural killer (NK) cells, i.e. abundant cytoplasm with many organelles, numerous electron dense granules, and irregular outline. On the other hand, a minority of Leu-7+ cells did not express the Leu-15 antigen and showed a clearly different ultrastructural feature in comparison to Leu-7+-Leu-15+ cells. Thus, the presence of the Leu-15 antigen on Leu-7+ cell surface corresponds to ultrastructural features specific to differentiated NK cells and may represent an expression of Leu-7+ cell differentiation. An alternative hypothesis may be that Leu-7+-Leu-15+ and Leu-7+-Leu-15- cells represent distinct cell lineages within non-A/non-Er Leu-7+ cells. Finally, the results of the present study provide proof that Leu-15 antigen is more frequently represented on non-A/non-Er Leu-15+ cells than on Er Leu-15+ cells.
Aged↗
Natural killer cells expressing the Leu-11 antigen display phagocytic activity for 2-aminoethylisothiouronium bromide hydrobromide- treated sheep red blood cells.
Natural killer (NK) cell subpopulations, identified by anti-Leu-7 and/or anti-Leu-11 monoclonal antibodies, have been investigated in immunoelectron microscopy by using a peroxidase-colloidal gold double labeling system. More than 90% of non-E rosetting/non-adherent Leu-11+ cells and approximately 60% of E rosetting Leu-11+ cells displayed phagocytic capacity for 2-aminoethylisothiouronium bromide hydrobromide treated sheep red blood cells, whereas Leu-7+ -Leu-11- cells consistently failed to ingest 2-aminoethylisothiouronium bromide hydrobromide treated sheep red blood cells. The phagocytic activity of Leu-11+ cells was not dependent on the Leu-7 antigen coexpression. Moreover, the NK capability of Leu-11+ cells has been verified. In both E rosetting and non-E rosetting/non-adherent cell populations, Leu-11+ enriched subsets displayed significantly higher NK capability when compared with Leu-11- cells. Previous reports provided evidence for different cytotoxic capability, recombinant human interleukin 2 mediated activation, and ultrastructural features of Leu-11+ cells in comparison to Leu-7+-Leu-11- cell subset. The data from the present investigation indicate that 2-aminoethylisothiouronium bromide hydrobromide treated sheep red blood cells phagocyting NK cells are confined to the Leu-11+ subset and give added strength to different function capabilities of Leu-11+ and Leu-7+-Leu-11- cells.
Aged↗
Polyvalent antigen-antibody interactions are required for the formation of electron-dense immune deposits in passive Heymann's nephritis.
In order to analyze the initial steps involved in the formation of subepithelial electron-dense immune deposits, the authors induced passive Heymann's nephritis in rats by intravenous injection of monoclonal or polyclonal antibodies to the relevant antigen, a 330,000-dalton brush border protein also expressed within coated pits of glomerular epithelial cells. Whereas both mono- and polyclonal antibodies induced deposits detectable by indirect immunofluorescence, electron-dense deposits were only found in glomerular capillary walls of rats injected with polyclonal antibodies. Immunoultrastructural analysis confirmed the subepithelial location of heterologous IgG: monoclonal antibodies were essentially confined to the coated pits of glomerular epithelial cells, whereas polyclonal antibodies were detected in coated pits and in the subepithelial electron-dense deposits. In the face of an excess of circulating antibody, gp 330 was not detectable in the deposits, but a striking increase in the number of endoplasmic reticula positive for gp 330 was found. The results indicate that highly cross-linked immune complexes formed by polyvalent antibodies on the epithelial cell surface are necessary for the induction of subepithelial electron-dense deposits.
Animals↗
Leu-7-positive cells with monocyte phenotype show different ultrastructural features in comparison to Leu-7-positive cells with T-cell phenotype.
The ultrastructural features of the Leu-7-positive - Leu-M3-positive cell subpopulation and the Leu-7-positive - Leu-4-positive cell subpopulation were characterized and compared using immunogold-immunoperoxidase double labelling with immunoelectron microscopy. The majority of Leu-7-positive cells coexpressed a monocyte phenotype and showed an ultrastructural pattern specific for functional natural killer (NK) cells, i.e. a low nuclear/cytoplasmic (N/C) ratio, an irregular outline, many cytoplasmic organelles and electron-dense granules. In contrast, only a minority of Leu-7-positive cells coexpressed a T phenotype, and these were characterized by a high N/C ratio, an even surface and the absence of electron-dense granules. Thus, Leu-7-positive - Leu-4-positive cells may by an immature form of NK cells, and Leu-7-positive - Leu-4-positive and Leu-7-positive - Leu-M3-positive cell subpopulations may represent different stages of Leu-7-positive cell differentiation.
Antibodies, Monoclonal↗
Ultrastructural characterization of human large granular lymphocyte subsets defined by the expression of HNK-1 (Leu-7), Leu-11, or both HNK-1 and Leu-11 antigens.
A peroxidase-colloidal gold double labeling system in immunoelectron microscopy was used to investigate the ultrastructural features of human large granular lymphocytes (LGL) subpopulations. Three subsets of LGL, Leu-7+-Leu-11-, Leu-7+-Leu-11+, Leu-7- -Leu-11+, were characterized using combinations of the monoclonal antibodies anti-Leu-7 and anti-Leu-11. They showed different ultrastructural patterns. In fact, Leu-7+-Leu-11- cells showed a high nuclear/cytoplasmic ratio (N/C), a round nucleus, a cytoplasm with few organelles, and a rather even surface. Moreover, most of them lacked electron-dense granules. On the other hand, Leu-11+ cells displayed a low N/C, an irregular-shaped nucleus, and a cytoplasm containing a well-developed Golgi apparatus, many mitochondria, vacuoles, vesicles, and numerous electron-dense granules. Moreover, they exhibited an irregular cell surface. Thus, Leu-7+-Leu-11- cells seemed to represent an immature form of LGL, while cells expressing the Leu-11 antigen showed a fine structure specific for functional NK cells. Our findings suggest that the expression of HNK-1 (Leu-7) and Leu-11 antigens respectively represents subsequent stages in NK cell differentiation.
Aged↗
Immunoperoxidase-immunogold double labelling in immunoelectronmicroscopy of large granular lymphocytes.
A method for better characterization of mononuclear cell subpopulations using detection of 2 surface antigens simultaneously in electron microscopy was developed with immunoperoxidase-immunogold double labelling. Monoclonal antibodies of IgG and IgM classes were used in the first step, and colloidal gold-labelled anti-mouse IgG antibody and peroxidase-labelled anti-mouse IgM antibody (mu chain-specific) in the second step. Immunoelectronmicroscopy with such double labelling improves ultrastructural analysis of mononuclear cell subpopulations.
Antigens, Surface↗
The fine structure of HNK-1 (Leu7) positive cells. A study using an immunoperoxidase technique.
The ultrastructural characteristics of HNK-1 (Leu7) positive cells, visualized with a peroxidase labelled anti-mouse IgM serum, were analysed. Our investigation demonstrates: 1) the majority of Leu7 positive cells has a low nuclear/cytoplasmic ratio (N/C), an irregular outline, a well developed smooth endoplasmic reticulum, parallel tubular arrays (PTA) and electron dense granules; 2) the minority of Leu7 positive cells has a high N/C, regular profiles and lacks electron dense granules. The presence of two distinct ultrastructural patterns within Leu7 positive cells may represent: 1) the expression of subsequent stages of cell differentiation; 2) two distinct Leu7 positive cell subpopulations.
Antibodies, Monoclonal↗
Macrophage--T-lymphocyte interaction in lichen planus. An electron microscopic and immunocytochemical study.
Papular lichen planus lesions from 12 patients were studied by a double-step immunocytochemical method to detect T-lymphocytes. Semithin sections were studied by light microscopy and ultrathin sections examined by electron microscopy. In the dermal infiltrate, many T-lymphocytes appeared closely juxtaposed to macrophages or Langerhans cells, frequently arranged in a rosette-like pattern. In the epidermis, T-lymphocytes were juxtaposed to macrophages or Langerhans cells and to degenerated keratinocytes. The close relationship between T-lymphocytes, macrophages or Langerhans cells and degenerated keratinocytes supports the hypothesis that lichen planus is immunological in nature: T-lymphocytes, after interacting with macrophages or Langerhans cells, become cytotoxic for keratinocytes.
Humans↗
Macrophage-T lymphocyte relationships in man's contact allergic reactions.
Seventeen biopsies from contact allergic reaction sites in sensitized patients were studied by electron microscopy and immunocytochemistry. Very intimate appositions of macrophages to T lymphocytes were frequently observed in the dermis at 6, 8 and 12 hours after application of the allergen. Such juxtapositions were seen less frequently after 24, 48 and 72 hours. These appositions seem to indicate that macrophages play an antigen-presenting role in human contact allergic reactions, as Langerhans cells seem to do.
Allergens↗
[Progesterone-induced changes in the endometrium. Ultrastructural studies of castrated, adrenalectomized and hypophysectomized impuberal rats].
Research has been made on the progesterone-induced effects upon endometrium on impuberal rats (either intact, or castrated, or castrated and adrenalectomized, or hypophysectomized) after an acute or a protracted treatment, which were made every third hour all through the day. It resulted that the hormone basically shows two distinct activities. The first one causes a modest awakening of the anabolical functions both in the lining and in the glandular epithelia, which results in the building up of small amounts of lipid and glycogen. The second one involves the lamina propria as well, and brings about morphological effects which can be superposed on those induced by estrogens. The former seems an autonomous activity and can mainly be found after long-lasting treatments. The latter, on the contrary is influenced by the administration time and can be detected only during a.m. treatments whereas it cannot be detected during p.m. and night treatments. Besides it is influenced by the hypophysal activity and in particular by gonadotropins. The possible mechanism of these influences are discussed.
Adrenalectomy↗
Identification of macrophages and of a T-lymphocytes subpopulation in normal human lymphnode by histochemical demonstration of alpha-naphthyl-acetate-esterasic activity.
The cell population of normal human lymphnode was studied by a histochemical technique showing alpha-naphthyl-acetate-esterasic activity. Two distinct cell populations were evidenced: a) macrophagic cells, bearing a diffused ANAE cytoplasmic positivity, most of which were in the subcapsular area, whereas a minority of them was found within the lymphatic nodules and the paracortical area; b) lymphocytic cells, bearing on ANAE positive cytoplasmic spot, most of which were in the paracortical area, whereas a minority of them was found within the lymphatic nodules. A discussion of the results we got, as compared with those which are reported by literature, confirms what is already well-known about the cell colonization of the various areas in the lymphnode. Besides it gives a chance to identify lymphocytes bearing an ANAE positive cytoplasmic spot with T lymphocytes belonging to the "helper-inducer" subclass.
Humans↗
Cell subpopulations in the paracortical area of the normal human lymphnode defined by monoclonal antibodies.
The cell subpopulations of normal human lymphnode were studied by immunohistochemical and immunoelectronmicroscopy techniques carried out by using monoclonal antibodies. OKT3 positive cells were demonstrated overwhelming in comparison to both OKT4 positive cells and OKT8 positive cells; furthermore la positive cells, dendritic in shape, were observed. Our results, compared to literature data, confirm that paracortex of limphnode is a T-dependent area. Moreover a possible role of the la positive dendritic cells in the immunological education of T helper-inducer lymphocytes was hypotised. Finally, our immunoelectronmicroscopic findings prove that OKT4 positive cells and OKT8 positive cells show different ultrastructural patterns.
Antibodies, Monoclonal↗
Remarks on early versus late lichen planus.
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Humans↗