ATPase-positive Dendritic Cells Research Articles

ATPase-positive dendritic cells in the limbal and corneal epithelium of guinea pigs after extended wear of hydrogel lenses.

It has been said that Langerhans cells can be induced to migrate into the central cornea by various stimuli. We investigated whether extended wear of hydrogel lenses induced the migration of Langerhans cells into the central cornea. Guinea-pig eyes were fitted with hydrogel contact lenses, and the number of adenosine triphosphatase (ATPase)-positive dendritic cells at the limbus, peripheral, and central corneal epithelium was quantified after 1, 2, 4, and 8 nights of extended wear. The cells were identified with histochemical procedures using ATPase stain. At baseline, ATPase-positive dendritic cells were seen at the limbus and peripheral cornea, with the density decreasing from limbus to peripheral cornea. There were no cells in the central cornea. With extended wear, cells increased in number at the peripheral cornea from 2 nights onward, and cells were seen in the central cornea from 4 nights onward. Extended wear of hydrogel lenses induced migration of ATPase-positive dendritic cells (Langerhans cells) into the central cornea. It is possible that they may play a role in the pathophysiology of some of the adverse events seen with contact lens wear.

ATPase and MHC class II molecules co-expression in Rana pipiens dendritic cells

Mammalian Langerhans cells are antigen-presenting cells located in different epithelia. These cells have a characteristic ultrastructural pattern, present a plasmatic membrane ATPase activity and constitutively express class II molecules of the major histocompatibility complex. ATPase-positive dendritic cells that are morphologically similar to Langerhans cells have also been found in amphibian epidermis. In order to demonstrate that ATPase-positive dendritic cells of amphibian epidermis express class II molecules and are present in other stratified epithelia, histochemical and immunohistochemical as well as ultrastructural analysis were performed. ATPase-positive dendritic cells and class II-positive dendritic cells were observed in epidermis, nictitant membrane and cornea. In epidermis the number of ATPase-positive dendritic cells was 656±186/mm 2 while class II-positive dendritic cells was 119±45/mm 2. Some ATPase-positive dendritic cells showed co-expression of class II molecules. These results suggest the existence of dendritic cell subsets in amphibians as is clearly demonstrated in mammals.

Epidermal langerhans cells in the terrestrial turtle, Kinosternum integrum

In mammalian epidermis, Langerhans cells (LC) are the only antigen-presenting dendritic cells that possess the ectoenzyme adenosine triphosphase (ATPase) and constitutively express class II molecules encoded by the major histocompatibility complex. Recently, we demonstrated the presence of LC in chicken epidermis. The aim of the present study is to demonstrate the presence of LC-like cells in turtle Kinosternum integrum, epidermis by light and ultrastructural ATPase histochemistry. ATPase-positive dendritic cells were observed in epidermal sheets whose maximum mean number was 192 cells/mm 2. Electron microscopy for ATPase stained sections showed an electrondense precipitate in the plasma membrane of dendritic clear cells located among basal and suprabasal keratinocytes, ultrastructurally similar to LC. In serial sections, some dendritic cells showed LC (Birbeck) granules. The present study demonstrates for the first time ATPase-positive dendritic cells, morphologically similar to LC, in reptilian epidermis.

Avian epidermis contains ATPase- and Ia-positive Langerhans-like cells.

The occurrence of cells resembling mammalian Langerhans cells in the avian epidermis was studied by ATPase histochemistry, Ia immunoreactivity and electron microscopy. The existence of MHC class II antigen-(Ia) expressing, ATPase-positive dendritic cells, which are ultrastructurally similar to mammalian Langerhans cells except for the absence of Birbeck granules, was demonstrated. These cells may be a basic component of the immune system of birds.

Depletion and Repopulation of Langerhans Cells in Nonsegmental Type Vitiligo

The role of Langerhans cells in the pathogenesis of nonsegmental type vitiligo is still unknown. In this study, biopsies were taken from 26 patients at various stages of nonsegmental type vitiligo and morphometrically observed to investigate the kinetics of Langerhans cells in patients at various stages of the disease. A marked depletion of OKT6-positive and ATPase-positive epidermal dendritic cells was noted in patients with active nonsegmental type vitiligo. A repopulation of both OKT6-positive and ATPase-positive epidermal dendritic cells was noted in patients with stable nonsegmental type vitiligo. Profound depletion of epidermal OKT6-positive and ATPase-positive dendritic cells was noted in patients with repigmenting nonsegmental type vitiligo receiving treatments involving topical use of 0.05% Fluocinonide cream or PUVA photochemotherapy. Transmission electron microscopy confirmed the absence of epidermal dendritic cells (Langerhans cells and intermediate cells) in patients with active and repigmenting nonsegmental type vitiligo. In active nonsegmental type vitiligo, two possible explanations are proposed for the depletion of OKT6-positive and ATPase-positive epidermal dendritic cells (presumptive Langerhans cells): 1) the cells are destroyed by cytotoxic factors released during the course of destruction of melanocytes in active vitiligo, and/or 2) they leave the epidermis and migrate to regional lymph nodes to present certain antigens which are released from certain destroyed epidermal cells (keratinocytes or melanocytes) during the course of active vitiligo. The repopulated epidermal Langerhans cells may result from phenotypically transformed dermal dendritic cells in the depigmented lesions of patients with stable vitiligo. Since various therapies which result in repigmentation deplete the density of epidermal Langerhans cells markedly, it is suggested that depletion of epidermal Langerhans cells in stable vitiligo may aid in repigmentation. It is also proposed that the repopulated epidermal Langerhans cells may play a role in inhibiting the proliferation of epidermal melanocytes in depigmented lesions of stable vitiligo, thus various methods of treatment which deplete the Langerhans cells may eventually aid in the repigmentation of nonsegmental type vitiligo.

The distribution of Langerhans cells in the dorsal mucosa of the mouse tongue.

Ultrastructure and distribution of Langerhans cells in the dorsal mucosa of mouse tongue were observed by light and electron microscopy and by ATPase histochemistry. The epithelium could be divided into papillary and interpapillary parts. Both papillae and interpapillae were orthokeratinized. The differences between the two parts were mainly due to the cellular characteristics of the prickle cell layer, granular layer and keratinized layer. In the interpapillae, tonofilaments in the cytoplasm of the prickle cells evenly dispersed without forming bundles, and the desmosomes were observed more clearly. The granular layer was less developed than that of the papillae. The cytoplasm of the keratinized layer stained with toluidine blue more lightly than that of papillae. By light microscopy, cells with clear cytoplasm occurred in the prickle cell layer just above the basal cell layer of interpapillae. They extended long cytoplasmic processes vertically, up to the granular layer and down to the basal layer. ATPase-positive dendritic cells were distributed in the interpapillae. By electron microscopy, Birbeck granule-containing Langerhans cells were observed in the interpapillae. The dendritic cells, which were observed as cells with clear cytoplasm by light microscopy or as ATPase-positive cells, agreed in morphology and distribution with the Langerhans cells which were observed by electron microscopy. In dd mice, ATPase-positive Langerhans cells were not observed at 2 weeks after birth, whereas they were observed at 3 and 4 weeks.

ATP-ase positive cells in human oral mucosa transplanted to nude mice.

A model to study the differentiation of human oral epithelium in vivo utilizing transplantation of human tissue to nude mice has been described. Previous studies have described the epithelial cells in this model. In this study we demonstrate that 8 d after transplantation, Langerhans cells, identified as ATP-ase positive dendritic cells, have almost disappeared from the transplanted epithelium whereas at day 21 after transplantation such cells were abundant. It is suggested that the ATP-ase positive cells which reappear in the transplanted epithelium are of mouse origin.

Labelling of murine epidermal Langerhans cells with H3-thymidine.

Epidermal Langerhans cells may be identified by light microscopy by their strongly positive reaction following incubation for ATPase activity. Intact sheets of epidermis from mice killed at various time intervals following a single pulse label of H3-thymidine were incubated to demonstrate ATPase activity and subsequently processed for autoradiography. In specimens taken one hour after labelling, many basal keratinocytes were labelled but very few ATPase-positive dendritic cells. At subsequent time periods a few pairs of labelled ATPase-positive cells were found but individually labelled cells were not observed. The findings suggest that epidermal Langerhans cells form a very stable (labelling index less than 0.01%) self-replicating population which divides to maintain cell spacing during growth. No evidence was found for migration and interchange of Langerhans cells with the connective tissue, or for an origin of Langerhans cells by transformation of another cell type.

A histochemical profile of lichen simplex.

SUMMARY Enzyme histochemical tests were performed on biopsies taken from patches of lichen simplex in eighteen patients and the results were contrasted with previous findings in psoriasis and lichen planus. The mitochondria! enzyme reactions were found to be increased within the epidermis, differing from those in lichen planus, in which there is a decreased density of reaction product for these tests. The non-specific esterase band was increased in width in lichen simplex contrasting with the absence of a discrete band in psoriasis. The DOPA reaction demonstrated the presence of positively reacting cells in the basal layer, and the ATPase reaction showed that there were many ATPase positive dendritic cells within the epidermis. It appears that in lichen simplex there is hyperplasia of all components of the epidermis in contrast to psoriasis where it seems the hyperplasia is almost restricted to keratinocytes.