Selective expression of a C-type lectin receptor, Clec12b, on skin mast cells

Several chemical compounds induce amine liberation from mast cells but do not necessarily provoque the granule expulsion. For example, poly-dl-lysine induces modifications of the cellular membrane permeability which promotes ion exchange at the level of mast cell granules. Few of them are expulsed but the majority remains in the cytoplasm and appears less dense to the electrons. A cytochemical analysis has been performed to determine the composition of these granules after the polylysine action.We have previously reported that it was possible to demonstrate polyanions on epon thin sections using a cetylpyridinium ferric thiocyanate method. Organic bases are selectively stained with cobalt thiocyanate and the sulfhydryle groups are characterized with a silver methenamine reaction. These techniques permit to reveal the mast cell granule constituents, i.e. heparin, biogenic amines and basic proteins.

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The relationship of IGE receptor topography to signaling activity in RBL-2H3 mast cells

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100085484 ◽

1991 ◽

Vol 49 ◽

pp. 236-237

Author(s):

J.R. Pfeiffer ◽

J.C. Seagrave ◽

C. Wofsy ◽

J.M. Oliver

Keyword(s):

Mast Cells ◽

Protein A ◽

Scattered Electron ◽

Ige Receptor ◽

Receptor Complexes ◽

Ige Binding ◽

Electron Imaging ◽

Small Clusters ◽

Relationship Of ◽

The Relationship

In RBL-2H3 rat leukemic mast cells, crosslinking IgE-receptor complexes with anti-IgE antibody leads to degranulation. Receptor crosslinking also stimulates the redistribution of receptors on the cell surface, a process that can be observed by labeling the anti-IgE with 15 nm protein A-gold particles as described in Stump et al. (1989), followed by back-scattered electron imaging (BEI) in the scanning electron microscope. We report that anti-IgE binding stimulates the redistribution of IgE-receptor complexes at 37“C from a dispersed topography (singlets and doublets; S/D) to distributions dominated sequentially by short chains, small clusters and large aggregates of crosslinked receptors. These patterns can be observed (Figure 1), quantified (Figure 2) and analyzed statistically. Cells incubated with 1 μg/ml anti-IgE, a concentration that stimulates maximum net secretion, redistribute receptors as far as chains and small clusters during a 15 min incubation period. At 3 and 10 μg/ml anti-IgE, net secretion is reduced and the majority of receptors redistribute rapidly into clusters and large aggregates.

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Magnesium and sulfur in mast cell and basophil granules of lower vertebrates in relation with histamine

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100132613 ◽

1992 ◽

Vol 50 (2) ◽

pp. 1596-1597

Author(s):

Kenichi Takaya

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Mast Cell ◽

Mast Cells ◽

Tree Frog ◽

X Ray ◽

Transmission Electron ◽

Scanning Transmission ◽

Fresh Frozen ◽

Ultrathin Sections

Mast cell and basophil granules of the vertebrate contain heparin or related sulfated proteoglycans. Histamine is also present in mammalian mast cells and basophils. However, no histamine is detected in mast cell granules of the amphibian or fish, while it is shown in those of reptiles and birds A quantitative x-ray microanalysis of mast cell granules of fresh frozen dried ultrathin sections of the tongue of Wistar rats and tree frogs disclosed high concentrations of sulfur in rat mast cell granules and those of sulfur and magnesium in the tree frog granules. Their concentrations in tree frog mast cell granules were closely correlated (r=0.94).Fresh frozen dried ultrathin sections and fresh air-dried prints of the tree frog tongue and spleen and young red-eared turtle (ca. 6 g) spleen and heart blood were examined by a quantitative energy-dispersive x-ray microanalysis (X-650, Kevex-7000) for the element constituents of the granules of mast cells and basophils. The specimens were observed by transmission electron microscopy (TEM) (80-200 kV) and followed by scanning transmission electron microscopy (STEM) under an analytical electron microscope (X-650) at an acceleration voltage of 40 kV and a specimen current of 0.2 nA. A spot analysis was performed in a STEM mode for 100 s at a specimen current of 2 nA on the mast cell and basophil granules and other areas of the cells. Histamine was examined by the o-phthalaldehyde method.

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The protease phenotype and crystalline nature of the granules of intraepithelial mast cells in Trichinella spiralis-infected mice

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100140464 ◽

1995 ◽

Vol 53 ◽

pp. 818-819

Author(s):

D.S. Friend ◽

N. Ghildyal ◽

M.F. Gurish ◽

K.F. Austen ◽

R.L. Stevens

Keyword(s):

Small Intestine ◽

Mast Cells ◽

Epithelial Cells ◽

Lamina Propria ◽

Trichinella Spiralis ◽

Intestinal Epithelial ◽

Carboxypeptidase A ◽

C3h Mice ◽

Granule Morphology ◽

Crystalline Nature

Trichinella spiralis induces a profound mastocytosis and eosinophilia in the small intestine of the infected mouse. Mouse mast cells (MC) store in their granules various combinations of at least five chymotryptic chymases [designated mouse MC protease (mMCP) 1 to 5], two tryptic proteases designated mMCP-6 and mMCP-7 and an exopeptidase, carboxypeptidase A (mMC-CPA). Using antipeptide, protease -specific antibodies to these MC granule proteases, immunohistochemistry was done to determine the distribution, number and protease phenotype of the MCs in the small intestine and spleen 10 to >60 days after Trichinella infection of BALB/c and C3H mice. TEM was performed to evaluate the granule morphology of the MCs between intestinal epithelial cells and in the lamina propria (mucosal MCs) and in the submucosa, muscle and serosa of the intestine (submucosal MCs).As noted in the table below, the number of submucosal MCs remained constant throughout the study. In contrast, on day 14, the number of MCs in the mucosa increased ~25 fold. Increased numbers of MCs were observed between epithelial cells in the mucosal crypts, in the lamina propria and to a lesser extent, between epithelial cells of the intestinal villi.

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Mast cell-nerve fiber interaction: Ultrastructural studies

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100159680 ◽

1990 ◽

Vol 48 (3) ◽

pp. 428-429

Author(s):

E.Y. Chi ◽

M.L. Su ◽

Y.T. Tien ◽

W.R. Henderson

Keyword(s):

Mast Cell ◽

Mast Cells ◽

Substance P ◽

Nerve Fiber ◽

Sensory Nerves ◽

Ultrastructural Studies ◽

Morphological Studies ◽

Granulocyte Infiltration ◽

Intracutaneous Injection ◽

Recent Attention

Recent attention has been directed to the interaction of the nerve and immune systems. The neuropeptide substance P, a tachykinnin which is a neurotransmitter in the central and peripheral nervous systems produces tissue swelling, augemntation of intersitial fibrin deposition and leukocyte infiltration after intracutaneous injection. There is a direct correlation reported between the extent of mast cell degranulation at the sites of injection and the tissue swelling or granulocyte infiltration. It has previously been demonstrated that antidromic electrical stimulation of sensory nerves induces degranulation of cutaneous mast cells, cutaneous vasodilation and augmented vascular permeability. Morphological studies have documented a close anatiomical association between mast cells and nonmyelinated nerves, that contain substance P and other neuropeptides. However, the presence of mast cells within nerve fasicles has not been previously examined ultrastructurally. In this study, we examined ultrastructurally the distribution of mast cells in the nerve fiber bundles located in the muscular connective tissue of rat tongues (n=20).

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Ultrastructural evidence for mast cell-macrophage interrelationships in the dura mater of the rat: Infrequent mast cell-nerve associations

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100159308 ◽

1990 ◽

Vol 48 (3) ◽

pp. 352-353

Author(s):

Ruth V.W. Dimlich

Keyword(s):

Mast Cell ◽

Mast Cells ◽

Dura Mater ◽

Spatial Relationship ◽

Potassium Phosphate ◽

Plasma Extravasation ◽

Close Spatial Relationship ◽

Male Wistar Rats ◽

Headache Pain ◽

Relationship Of

Mast cells in the dura mater of the rat may play a role in cerebral pathologies including neurogenic inflammation (vasodilation; plasma extravasation) and headache pain . As has been suggested for other tissues, dural mast cells may exhibit a close spatial relationship to nerves. There has been no detailed ultrastructural description of mast cells in this tissue; therefore, the goals of this study were to provide this analysis and to determine the spatial relationship of mast cells to nerves and other components of the dura mater in the rat.Four adult anesthetized male Wistar rats (290-400 g) were fixed by perfusion through the heart with 2% glutaraldehyde and 2.8% paraformaldehyde in a potassium phosphate buffer (pH 7.4) for 30 min. The head of each rat was removed and stored in fixative for a minimum of 24 h at which time the dural coverings were removed and dissected into samples that included the middle meningeal vasculature. Samples were routinely processed and flat embedded in LX 112. Thick (1 um) sections from a minimum of 3 blocks per rat were stained with toluidine blue (0.5% aqueous).

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