ATPase-positive Langerhans Cells Research Articles

Dermatophyte infection encircling vitiligo.

Dermatophyte infection encircling vitiligo.

The effect of PUVA on langerhans cells in rat oral epithelium photosensitized with systemic methoxsalen or topical trioxsalen.

Ultraviolet-A radiation (UVA) of the oral mucosa after photosensitization with either systemic methoxsalen (8-MOP) or topical trioxsalen (TMP), i.e. mouth-PUVA, has been reported to be successful in the treatment of oral lichenoid lesions. In the case of PUVA treatment of skin disorders, local immune suppressive effects have been demonstrated, and the antigen presenting epithelial Langerhans cells (LCs) have been shown to be especially sensitive to ultraviolet treatments. Our aim was to compare the photobiological effects of PUVA in oral mucous membrane (OMM) using topical TMP or systemic 8-MOP photosensitization. Rat OMM photosensitized with topical TMP or systemic 8-MOP was treated with PUVA using UVA doses of 1-8 J/cm2. The LCs were demonstrated in epithelial sheets of the treated OMM with ATPase staining. Both treatments caused a sim ilar, dose-dependent depletion of ATPase-positive LCs, with a maximal depletion of 80% or 73% with 8 J/cm2 at 2 days after irradiation as photosensitized with TMP or 8-MOP, respectively. This contrasts with earlier published findings in human skin, where topical TMP is an order of magnitude greater a sensitizer than 8-MOP, and PUVA-induced depletion of LCs occurs maximally 5 days after irradiation. The depletion of LCs of rat OMM after PUVA treatment is greater using topical TMP compared to systemic 8-MOP, but the difference is significantly smaller than reported earlier in human skin.

Langerhans cell density and serological changes following intradermal immunisation of mice with dengue 2 virus

After the introduction of the dengue-2 (16681) virus by intradermal (i.d.) injection into the footpads of mice, Langerhans cells (LCs) increased in numbers within 24 h at the site of injection and neutralising antibody developed. On comparing the i.d. and intramuscular (i.m.) routes, antibody was produced more rapidly and at higher levels when the virus was injected by the i.d. route. Subsequent re-challenge by the i.d. route produced an even more rapid serological response with all mice producing significant neutralising titres within 12 h. Numbers of ATPase-positive LCs varied with time. A significant sharp drop in LC densities in the early post-injection phase directly correlated with the increased numbers of dendritic cells in the superficial dermis and interfollicular sinuses of draining lymph nodes (LN). Immunofluorescence showed the presence of viral antigen in the footpad epidermis and draining LN within minutes or within 2 h of challenge, respectively.

Increase in epidermal ATPase-positive Langerhans cells following topical application of 70% deacetylated chitin (DAC-70) in DNCB-sensitized contact dermatitis in guinea pigs preliminary report

Chitin is a polymer of D-glucosamine, beta-poly-N-acetyl D-glucosamine. The chitin derivative, 70% deacetylated chitin (DAC-70), is immunopotentiating. The present study was conducted to determine the immunoregulatory events in skin following topical application of DAC-70 to DNCB-sensitized contact dermatitis in guinea pigs. On the 3rd day of treatment, DNCB-induced erythema was reduced in all five guinea pigs treated with 10% or 3.5% DAC-70 ointment. On the 7th day of treatment, ATPase-positive Langerhans cell (LC) density in epidermal sheets was 1021 + 131/mm2 (mean + SD) for 10% DAC-70-treated skin, and 1000 + 130/mm2 for 3.5% DAC-70-treated skin, both values exceeding 782 + 65/mm2 for normal epidermis. The value in DAC-70-treated samples was significantly greater (P < 0.01) than in normal epidermis. DAC-70 thus appears to have an immunoregulatory effect by increasing the number of epidermal LCs.

Langerhans cells in the developing mucosal epithelium of mice.

The presence of Langerhans cells in the developing mucosal epithelium of mice was investigated by ATPase histochemistry and by electron microscopy. In the stratified squamous epithelium of the tongue and forestomach, a few ATPase-positive Langerhans cells could be recognized at 1 or 2 weeks after birth. They increased in number by 3 weeks of age, but the density was lower than that in the epidermis. The ATPase-positive cells in the mucosal epithelium had longer (18-22 microns) dendritic processes; each cell thus occupied a large space. The mucosal Langerhans cell with elongated dendritic processes may well be responsible for the surveillance of a wide area in the defense system of the mucous membrane. The cells had a clear cytoplasm among keratinocytes in the basal cell layer and, under the electron microscope, showed characteristics similar to those of the epidermal Langerhans cells; Birbeck granules were also recognizable in the cytoplasm.

Photoreversal of the ultraviolet radiation-induced disappearance of ATPase-positive Langerhans cells in the epidermis of Monodelphis domestica.

The present study was undertaken to explore the possible causes of ultraviolet radiation (UVR)-induced disappearance of ATPase-positive, epidermal Langerhans cells (LC). Monodelphis domestica was used because it has the capacity for photoreactivation of UVR-induced pyrimidine dimers in epidermal DNA. Single, 330 J/m2 (ears) or 500 J/m2 (back) UVR exposures (FS-40 sunlamps) reduced the numbers of ATPase-positive epidermal LC in M. domestica ears to approximately 15% of those in unirradiated ears and approximately 37% of those in unirradiated dorsal skin. Immediate 90-minute exposures to photoreactivating light (PRL, 320-400 nm) post-UVR reversed the effects of UVR, resulting in ATPase-positive LC numbers not being significantly different from controls. Exposure to PRL immediately preceeding UVR did not prevent ATPase-positive LC disappearance. The photoreactivation of UVR-induced ATPase-positive LC disappearance indicates that DNA damage (pyrimidine dimers) is involved in the loss of ATPase-positive LC.

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.

Oxygen Intermediates Are Involved in Ultraviolet Radiation-Induced Damage of Langerhans Cells

Experiments were conducted to determine whether ultraviolet (UV) radiation exerts its effect through the generation of oxygen intermediates on Langerhans cells (LC). Guinea pigs were exposed to one single dose of UVB (0.9-2.7J/cm2), and biopsy specimens were taken 5 days after the irradiation. The population of LC was evaluated using ATPase-stained epidermal sheets. These exposures reduced the number of LC to 20-25% of the original density. On the other hand, superoxide dismutase (SOD) (0.02-0.2 mg), a scavenger of superoxide anion, which had been injected intradermally just before UV radiation, significantly prevented the depletion of LC, although not completely (37-40% of the original density). The injection immediately after the exposure was still significantly effective, but less so. Other scavengers of oxygen intermediates including catalase, D-mannitol, and L-histidine revealed no detectable effect. A single exposure of UVB at doses of 0.3-0.6 J/cm2 did not deplete the ATPase-positive LC. However, the same dose of UVB reduced the number of LC to 70%, when exposed after the injection of an SOD inactivator, diethyldithiocarbamate, possibly due to inactivation of physiologically existing SOD. These observations indicate that oxygen intermediates such as superoxide anion or its subsequent species are generated by UV radiation exposure and damage the epidermal LC.

Development of ATPase-positive, immature Langerhans cells in the fetal mouse epidermis and their maturation during the early postnatal period.

The development and maturation of Langerhans cells during the differentiation of skin was studied in mice from fetal day 13 to adult using 3 indices: ATPase activity: ultrastructure; and quantitative evaluation of the cell population. ATPase-positive Langerhans cells appeared in the epidermis at first at fetal day 16, and they increased in number in the differentiating epidermis during the late fetal period. The earliest appearance of Birbeck granules was at postnatal day 4. Cored tubules were also formed in the Langerhans cells in the dermis at around the same age. The cells containing Birbeck granules or cored tubules are considered to be mature Langerhans cells. In the Langerhans-cell lineage, those cells in the epidermis at stages earlier than postnatal day 4 and not yet containing specific organelles are considered to be immature Langerhans cells. These immature Langerhans cells can be identified ultrastructurally in the epidermis at fetal day 16, coinciding with the appearance of ATPase-positive cells. The increase in the number of immature Langerhans cells during the perinatal period was shown by quantitative analysis of nuclear density and relative Langerhans-cell area on the electron micrographs. It is concluded that ATPase is a marker of the Langerhans-cell lineage from the early development stages, while Birbeck granules and cored tubules are markers that identify mature Langerhans cells in electron micrographs.

Quantitative studies of the fate of epidermal Langerhans cells after X-irradiation of guinea-pig and mouse footpad skin.

Langerhans cell numbers, morphology and distribution were observed in cross sections of footpad epidermis at intervals from 1 to 28 days after exposure of the hind feet of CBA/H mice or albino guinea-pigs to a single absorbed dose of 20 Gy (2000 rad) of X-rays. In mice, the number of Langerhans cells reactive with anti-macrophage F4/80 monoclonal antibody steadily declined by approximately 85% within 10 days after irradiation, consistent with previous studies, in which Langerhans cells were identified in epidermal sheets by ATPase activity or presence of Birbeck granules. Remaining Langerhans cells were exceptionally dendritic. Very few Birbeck granule-containing cells were found in murine popliteal lymph nodes before or after irradiation but damaged cells were present in superficial strata of irradiated epidermis. The morphology and number of epidermal F4/80-positive cells approached normal by 15 days after irradiation. In guinea-pigs, gradual suprabasal movement and loss of rounded, ATPase-positive Langerhans cells from the epidermis were detectable from 5 to 20 days after irradiation but the magnitude of the cell loss and redistribution was partially obscured by the simultaneous appearance of clusters of replacement Langerhans cells in the basal layer and by keratinocyte hyperplasia.

Distribution of ATPase-positive Langerhans cells in normal adult human skin

The distribution of ATPase-positive Langerhans cells (LC) was investigated in 117 specimens of normal adult human skin and mucosa taken from different areas of the body. Although there were significant variations in the numbers of LC in each area examined, skin from the face and neck contained the highest density of cells (976 +/- 30.93/mm2). The densities of LC in trunk skin (740 +/- 28.97/mm2), scalp (693 +/- 69.56/mm2) and arm or leg skin (640 +/- 40.95/mm2) were similar. Buccal mucosa had significantly fewer LC (567 +/- 42.94/mm2) than trunk skin, and sacrococcyx skin and palm and sole skin displayed the smallest number of these cells (267 +/- 56.14/mm2 and, 189 +/- 19.15/mm2 respectively). No ATPase-positive LC were detected in the centre of two corneal specimens.

Langerhans cells in candidal leukoplakia.

Using histochemical and immunohistochemical methods, we examined specimens of candidal leukoplakia from the oral mucosa of 5 smokers to determine the morphological relationships between Candida and Langerhans cells (LC) in tissue sections. LC were fairly evenly distributed in control sections, but had a patchy distribution in lesions. Fewer LC were found in lesions than in control tissue, but the difference was not statistically significant. Candidal antigens were not detected on LC by the methods used, but we found ATPase-positive LC among, or at least near, intraepithelial candidal hyphae. However, sections double-reacted with anti-Candida and T6 antibodies to label candidal antigens and LC, respectively, showed a clear zone of epithelium between the T6-positive LC and the candidal hyphae. The difference in distribution of ATPase-positive and T6-positive LC may indicate locations of 2 subtypes of LC, or a change in T6 antigen expression by the LC closest to the candidal hyphae.

Dose Response of Langerhans Cells in Mouse Footpad Epidermis after X Irradiation

Effects of a range (2-50 Gy) of single doses of 250 kV X rays on epidermal Langerhans cells in vivo were quantified in groups of CBA/CaH mice. Animals were sacrificed and compared with controls on the 10th day after local irradiation of their hind feet, when Langerhans cell numbers were at a minimum. ATPase-positive Langerhans cells in sheets of footpad epidermis were counted by light microscopy and cells with Birbeck granules were enumerated by electron microscopy. Both methods revealed a dose-dependent loss of Langerhans cells after ionizing radiation. Fifty percent of the ATPase-positive cells were lost after 14.4 +/- 1.3 Gy, and 50% of Birbeck granule-containing cells were lost after 17.9 +/- 4.2 Gy, suggesting that differentiated epidermal Langerhans cells are radioresistant. Loss of equivalent proportions of ATPase-positive and ultrastructurally identifiable cells after a range of doses indicates that X rays do not merely alter Langerhans cell surface markers but actually deplete the epidermal population of these cells.

RA can alter the distribution of ATPase-positive Langerhans cells in the hamster cheek pouch in association with DMBA application.

Thirty-six young adult male and female Syrian hamsters were divided into four groups. Group 1 (N = 6) was treated with mineral oil, Group 2 (N = 12) was treated with 7,12-dimethylbenz[a]anthracene (DMBA), Group 3 (N = 12) was treated with DMBA and 13-cis-retinoic acid (RA), and Group 4 (N = 6) was treated with RA only. The hamsters were treated three times a week for six weeks. When the DMBA-treated animals were also treated with RA, tumor formation was inhibited. In the DMBA-treated animals that did not have RA, there was a significant reduction in the number of Langerhans cells (LCs) located interfocally and in foci compared with controls (p less than or equal to 0.001). The systemic administration of 10 mg of RA significantly increased the number of ATPase-positive LCs in the focal aggregates (p less than or equal to 0.001). Interfocally, the number of ATPase-positive LCs was statistically elevated in pouches from RA- and DMBA-treated animals (Group 2 vs. Group 3, p less than or equal to 0.01). Following the administration of RA (Group 4), there was a statistically significant increase of LCs interfocally compared with Groups 2 or 3 (p less than or equal to 0.001). RA administered alone resulted in a small increase in foci compared with Group 3 but in a significant decrease compared with the control group (p less than or equal to 0.001). Systemic RA appears to not only affect the number of ATPase-positive LCs but also to alter the distribution of these cells in DMBA-treated pouches.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of Indomethacin on Alteration of ATPase-Positive Langerhans Cell Density and Cutaneous Sunburn Reaction Induced by Ultraviolet-B Radiation

We have investigated the effect of ultraviolet-B (UVB) irradiation on the density of epidermal ATPase-positive Langerhans cells, and the modulation of this effect by indomethacin (IND). Depilated backs of albino guinea pigs were exposed to varying doses of UVB (10-550 mJ/cm2). Skin biopsies were taken serially. There was an UVB dose-dependent decrease in the density of dendritic epidermal Langerhans cells, as identified by their membrane ATPase activity. This was accompanied by thinning and shortening, or disappearance of dendritic processes. Such changes were followed by a gradual recovery of the cell density to preirradiation level by day 21. Despite the high doses of UVB given, the maximal decrease in the density of ATPase-positive cells was only 58%. Topical application of IND, a prostaglandin-synthetase inhibitor, after irradiation resulted in a decrease of the erythema; however, the decrease in the density of ATPase-positive cells was still observed. In contrast, guinea pigs that received IND topically prior to irradiation showed a decrease erythemal response, but failed to show any decrease in the density of ATPase-positive cells. Administration of IND orally for 3 days prior to UVB exposure did not prevent the decrease in the cell density. The protective effect of topical IND, applied prior to irradiation, may be explained by its in vitro absorbance at both the UVB and UVA ranges. Topical application of IND 20 min prior to exposure to UVB in 2 human subjects resulted in an increase in the minimal erythema dose, giving a sun protection factor of 1.6, which is comparable to that produced by an equimolar concentration of para-aminobenzoic acid solution. The sun-protective property of IND, together with its activity as a prostaglandin synthetase inhibitor, indicate that it potentially could be a useful sunscreen agent. Its clinical safety and efficacy, however, remain to be determined.

The Effects of 8-Methoxypsoralen and Long-wave Ultraviolet Light on Langerhans Cell

The effect of 8-methoxypsoralen plus long-wave ultraviolet light (PUVA) on Langerhans cell was examined in guinea pigs using ATPase staining method. The number of ATPase-positive Langerhans cells gradually decreased until 5 to 7 days after PUVA treatment, when it was found to be less than 10% to 20% of the original density. Even the ATPase-positive cells exhibited abnormal appearance. The dendritic processes were shortened or disappeared and the central body became oval or round. These changes in population and morphology of Langerhans cell almost returned to normal by 14 days. The inhibitory effect of PUVA on the induction of contact hypersensitivity may be partly due to the alterations of Langerhans cells. Furthermore, the damage on the antigen-presenting cells may accelerate the development of PUVA-induced tumors.

Natural and Perturbed Distributions of Langerhans Cells: Responses to Ultraviolet Light, Heterotopic Skin Grafting, and Dinitrofluorobenzene Sensitization

Epidermal Langerhans cells exhibit many features of macrophages/monocytes. Both bear surface receptors for the Fc portion of immunoglobulin molecules and the C3b complement component. Both take up, process, and present antigens to reactive lymphocytes in an effective fashion, and they display on their cell surfaces the alloantigenic determinants encoded by the I region of the major histocompatibility complex. In view of these facts, we explored the extent to which cutaneous sites with unusual immunologic attributes might correspondingly have maldistributions or decreased surface densities of Langerhans cells. Common body sites such as the ear, back, and abdominal wall skin in hamsters, mice, and guinea pigs had regularly distributed ATPase-positive Langerhans cells in surface densities between 500 and 1,500 cells/mm2. In contrast, hamster cheek pouch epithelium had fewer than 200 Langerhans cells/mm2 and murine tail skin exhibited both a decreased density and an unusual gridlike distribution of the cells. Langerhans cells were never demonstrated in corneal epithelium. Perturbation of body wall skin with ultraviolet light and with dinitrofluorobenzene temporarily depleted the skin of ATPase-positive Langerhans cells. Heterotopic grafts of hamster cheek pouch and murine tail skin tended to accumulate Langerhans cells and to become more like body wall skin. The concordance of Langerhans cell aberrations and unusual immunologic features of corneal cheek pouches and tail skins suggests the possibility that intentional perturbations of surface Langerhans cells, as with UVL, might achieve unusual immunologic reactions within normal body wall skin.