A quantitative analysis of the Langerhans cell in chronic plaque psoriasis

The mouse monoclonal antibody, NAI/34, in a standard immunoperoxidase technique, was used to count Langerhans cells in skin obtained from nine patients who were suffering from chronic plaque psoriasis. Biopsies were obtained from involved skin, clinically uninvolved skin and clinically healed skin following treatment with tar and/or dithranol. Langerhans cell numbers were expressed both as the absolute number of Langerhans cells per linear millimetre of surface epidermis and also as the number of Langerhans cells overlying 200 basal cells. An analysis of variance showed that in the active edge of a plaque of psoriasis, the absolute number of Langerhans cells was increased compared to adjacent uninvolved skin but when expressed as a ratio relative to the number of basal cells present, the number was decreased. This ratio returned to normal in healed skin. The ratio of Langerhans cells to basal cells in clinically uninvolved and in healed skin is the same ratio as we have found in over 100 specimens of normal skin obtained from non-psoriatic individuals.     

Langerhans cell density in epithelial skin tumors correlates with epithelial differentiation but not with the peritumoral infiltrate

We investigated the intraepithelial density of Langerhans cells in 17 epithelial skin tumors by immunohistologic and morphometric methods. There was a significant difference between seborrheic keratosis (Langerhans cell density 431 +/- 31/mm2; normal epidermis: 378 +/- 20/mm2), basal cell carcinoma (28 +/- 6/mm2), and squamous cell carcinoma (100 +/- 21/mm2). No correlation was found between the Langerhans cell density and the number of intraepithelial T lymphocytes or the extent of the peritumoral inflammatory infiltrate. A significant inverse correlation was demonstrated between mean nuclear area of the epithelial tissue and the Langerhans cell density (r = -0.7; p less than 0.05). These data indicate that the number of Langerhans cells does not influence the extent of the antitumoral immune response. The correlation with the level of epithelial differentiation may be due to different homing conditions.     

CD1a、CD68在继发性瘢痕疙瘩中的表达及意义

目的 探讨继发性瘢痕疙瘩皮损中表皮朗格汉斯细胞（LC）和真皮CD68阳性组织细胞的分布和密度。方法 取30例继发性瘢痕疙瘩患者的皮损、14例正常人皮肤组织切片进行CD1a和CD68免疫组化染色。以测微尺标定目镜方格计数方格内阳性细胞数,计算出单位面积内细胞的密度。组间比较采用SPSS软件进行 Student t检验。结果 在继发性瘢痕疙瘩表皮内CD1a阳性LC密度为（61 ± 49）个/mm2,正常表皮为（258 ± 61）个/mm2,两组比较,t = 9.88,P ＜ 0.01;继发性瘢痕疙瘩真皮CD1a阳性细胞密度为（40 ± 65）个/mm2。继发性瘢痕疙瘩表皮中无CD68阳性细胞,真皮内CD68阳性组织细胞密度为（287 ± 73）/mm2,正常皮肤为（290 ± 22）个/mm2,两组比较,t = 0.02,P ＞ 0.05。继发性瘢痕疙瘩真皮浅层CD68阳性组织细胞占真皮中所有细胞的62% ± 12%,而正常皮肤为70% ± 14%,两组比较,t = 2.66,P ＜ 0.05。 结论 继发性瘢痕疙瘩表皮中LC减少,无CD68阳性的细胞。真皮中LC增多;真皮浅层CD68阳性组织细胞占真皮中所有细胞的比例下降。     

A strikingly constant ratio exists between Langerhans cells and other epidermal cells in human skin. A stereologic study using the optical disector method and the confocal laser scanning microscope

Langerhans cells play an important part in the immune surveillance of the human epidermis. Therefore, a certain distribution and numerical relationship to other epidermal cells can be expected. To quantify epidermal Langerhans cells population extensive studies have been performed using two-dimensional quantification methods on vertical sections or epidermal sheet preparations. Whereas methods using vertical sections were complicated considerably by the sampling procedure, the dendritic shape, and the suprabasal, nonrandom distribution of Langerhans cells, epidermal sheet preparations have their limitations regarding the numerical relationship of Langerhans cells to total epidermal cells and the epidermal morphology as such. In order to improve the validity of data the three-dimensional dissector method combined with confocal laser scanning microscopy has been applied to quantify the number of Langerhans cells and other epidermal cell nuclei per volume unit in cryosections of 24 punch biopsies of normal breast skin of eight women. Furthermore, the ratio of Langerhans cells to other epidermal cells, their number per biopsy, and per skin surface area were calculated. To minimize the bias by shrinkage the reference volume was estimated using Cavalieri's principle. A constant ratio of one Langerhans cells to 53 other epidermal cells was identified in breast skin (interindividual correlation coefficient: 0.952, p < 0.0001). Thus, Langerhans cells represent 1.86% of all epidermal cells; however, a wide interindividual range was found for the number of Langerhans cells per mm2 (912-1806; mean +/- SD 1394 +/- 321) and other epidermal cells per mm2 (47,315-104,588; mean +/- SD 73,952 +/- 19,426). This explains the conflicting results achieved by conventional morphometric assessments relating cell numbers to skin surface area, ignoring the varying thickness of the epidermis. The surprisingly constant relationship of Langerhans cells to other epidermal cells stresses the hypothesis of an epidermal Langerhans cells unit where one Langerhans cells seems to be responsible for the immune surveillance of 53 epidermal cells.     

Kinetics of epidermal Langerhans cells

Langerhans cells are considered to play an important role in the initiation of the immune response. This study was performed in order to analyze the kinetics of the Langerhans cell population under different experimental conditions. Using tritiated thymidine, the number of labeled Langerhans cells (demonstrated by the Leucinaminopeptidase reaction), and of labeled basal keratinocytes was investigated by autoradiography in guinea pig skin in vivo, before and 2, 5 and 8 days after stripping and before and 2, 5 and 8 days after initiation of repeated topical exposures to a 0.25% solution of dinitrochlorobenzene (DNCB). In addition the total number of Langerhans cells per mm2 was determined before and after DNCB treatment of epidermal guinea pig sheet preparations using the ATPase reaction. A total of more than 100,000 cell as of basal keratinocytes was stimulated significantly (by statistical analysis), both by stripping and by application of DNCB. After stripping, however, the increase of the Langerhans cell turnover was found to be secondary to the turnover of basal keratinocytes, whereas after DNCB application the increase in the proliferative activity of Langerhans cells appeared as the primary event in epidermal cellular kinetics.     

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.     

Density and morphology of Langerhans cells in basal cell carcinomas of the face and trunk

We investigated the density and morphology of Langerhans cells in epidermal sheets of basal cell carcinomas in chronically sun-exposed skin (face) and less exposed skin (trunk) of 65 patients. Langerhans cells in perilesional and control skin at the same anatomical sites as the tumours were also examined. Two markers (ATPase and OKT6) were used in a parallel fashion to identify Langerhans cells. The density of the cells was reduced, and their morphology was changed in epidermis overlying tumours of both the face and trunk. These alterations were confined to tumour areas, as Langerhans cells in perilesional skin were normal when compared with control skin at both anatomical sites. Results with both markers were the same.     

Clinical and histopathologic characteristics of trichrome vitiligo

BACKGROUND: The term trichrome vitiligo describes lesions that have a tan zone of varying width between normal and totally depigmented skin, which exhibits an intermediate hue. However, the pathogenesis and the histopathologic characteristics of trichrome vitiligo are unknown. OBJECTIVE: Our purpose was to investigate the clinical and histopathologic characteristics and the pathogenesis of trichrome vitiligo. METHODS: Four punch biopsy specimens were taken from 21 patients with trichrome vitiligo; they were from vitiliginous skin, light brown skin, perilesional normal skin, and normal skin as far as 5 cm from the nearest vitiligo spot. The sections were stained with hematoxylin-eosin; in selected cases, we performed immunohistochemical staining with S-100 protein and CD1a. RESULTS: Trichrome vitiligo occurred most frequently on the trunk in active vitiligo vulgaris. Focal vacuolar degeneration of the basal cell layer and mild inflammatory cell infiltration of the epidermis and dermis were more prominent in light brown skin and perilesional normal skin than in vitiliginous skin and normal skin. The number of melanocytes was decreased in light brown skin compared with perilesional normal skin (P <.05) and in vitiliginous skin compared with light brown skin (P <.05); a few melanocytes were observed even in skin affected by trichrome vitiligo. The number of Langerhans cells was increased in the epidermis of light brown skin and perilesional normal skin compared with vitiliginous and normal skin (P <.05). PUVA therapy yielded excellent repigmentation. CONCLUSION: Trichrome vitiligo is a variant of active vitiligo. The changes of melanocytes, keratinocytes, and Langerhans cells may be involved in the pathogenesis of depigmentation in trichrome vitiligo.     

The organization of human epidermis: functional epidermal units and phi proportionality

The concept that mammalian epidermis is structurally organized into functional epidermal units has been proposed on the basis of stratum corneum (SC) architecture, proliferation kinetics, melanocyte:keratinocyte ratios (1:36), and, more recently, Langerhans cell: epidermal cell ratios (1:53). This article examines the concept of functional epidermal units in human skin in which the maintenance of phi (1.618034) proportionality provides a central organizing principle. The following empirical measurements were used: 75,346 nucleated epidermal cells per mm2, 1394 Langerhans cells per mm2, 1999 melanocytes per mm2, 16 (SC) layers, 900-microm2 corneocyte surface area, 17,778 corneocytes per mm2, 14-d (SC) turnover time, and 93,124 per mm2 total epidermal cells. Given these empirical data: (1) the number of corneocytes is a mean proportional between the sum of the Langerhans cell + melanocyte populations and the number of epidermal cells, 3393/17,778-17,778/93,124; (2) the ratio of nucleated epidermal cells over corneocytes is phi proportional, 75,346/17,778 approximately phi3; (3) assuming similar 14-d turnover times for the (SC) and Malpighian epidermis, the number of corneocytes results from subtraction of a cellular fraction equal to approximately 2/phi2 x the number of living cells, 75,436 - (2/phi2 x 75,346) approximately 17,778; and (4) if total epidermal turnover time equals (SC) turnover time x the ratio of living/dead cells, then compartmental turnover times are unequal (14 d for (SC) to 45.3 d for nucleated epidermis approximately 1/2phi) and cellular replacement rates are 52.9 corneocytes/69.3 keratinocytes per mm2 per h approximately 2/phi2. These empirically derived equivalences provide logicomathematical support for the presence of functional epidermal units in human skin. Validation of a phi proportional unit architecture in human epidermis will be important for tissue engineering of skin and the design of instruments for skin measurement.     

Sex differences in the densities of epidermal Langerhans cells of the mouse

Cutaneous immune reactions are known to show sexual dimorphism. Langerhans cells (LCs) are bone marrow-derived immune cells in the epidermis and are essential to immune reactions in the skin. In the present research, a study was made of the differences in LC density of male and female mice. Epidermal sheets were separated from the skin of the glabrous part of hind limbs and ears of specific pathogen-free (SPF) mice by ethylenediaminetetraacetic acid (EDTA) treatment and stained for adenosine triphosphatase (ATPase) activity. The density of LCs of hind limb epidermis in male C57BL/6 (823 +/- 20/mm2) and BALB/c (1689 +/- 66/mm2) mice was significantly less than that in females (1363 +/- 52/mm2, p less than 0.001; 2249 +/- 105/mm2, p less than 0.001, respectively). Langerhans cell density in the ears of male C57BL/6 (465 +/- 24/mm2) mice was also significantly less than that in females (542 +/- 17/mm2, p less than 0.02). Although ovariectomy failed to bring about any change in the LC density of hind limb epidermis in female C57BL/6 mice, the LC density in male C57BL/6 mice increased significantly at 4 weeks following orchiectomy (sham operation, 564 +/- 27/mm2; castration, 1179 +/- 49/mm2, p less than 0.001). These results indicate that mouse epidermal LC density depends on sex, i.e., male mice have fewer LCs than female mice. The reduction in LC density in males may possibly be caused by the testis.     

Immunohistochemical study of Langerhans cells in skin tumors

The behavior of Langerhans cells in skin tumors was investigated by immunohistochemical techniques using OKT6. OKT6-positive cells were numerous in squamous cell carcinomas, seborrheic keratoses and keratoacanthomas. They were rare in basal cell carcinomas, Bowen's disease, eccrine poromas, extramammary Paget's disease and warts. In solar keratosis, the number of OKT6-positive cells was almost equal or slightly larger compared to the normal epidermis. These results indicate that the density of Langerhans cells may not correlate with the degree of malignancy but, to a certain extent, with the nature of the membrane of tumor cells occurring e.g. during keratinization.     

Stimulation of the recruitment of epidermal Langerhans cells by splenopentin

Summary Splenopentin (SP-5: Arg-Lys-Glu-Val-Tyr), a pentapeptide corresponding to the residues 32–36 of the splenic hormone splenin, increases dose-dependently the number of bone marrow colonies (M and GM colonies). Therefore, we tested the stimulatory effect of SP-5 on the recruitment of epidermal Langerhans cells in skin deprived of these cells. A high dose of cyclophosphamide or dexamethasone led to a drastic decrease of LC density in murine skin with slow and incomplete restoration. SP-5 accelerated Langerhans cell recruitment and led to pretreatment levels of Langerhans cell density in the skin. These results indicate that SP-5 may possibly be used to treat disorders (e.g., HIV infection) where impaired Langerhans cell density and function can lead to secondary cutaneous infections.     

朗格汉斯细胞表达与尖锐湿疣发病的相关性研究

目的：探讨朗格汉斯细胞（LC）的表达与尖锐湿疣（CA）发病的相关性。方法：采用免疫组化法对28例CA皮损和10例正常皮肤组织进行CD1a^＋LC染色;应用图像分析技术对CD1a^＋LC进行定量分析。结果：CA皮损中CD1a^＋LC数目明显减少,分布不规则,形态不典型,结构不完整,树突状突起明显减少、缩短或消失;CA组CD1a^＋LC数目较对照组明显减少（P〈0.05）。经图像分析显示CA组平均CD1a^＋LC含量明显低于对照组（P〈0.05）。结论：尖锐湿疣中CD1a^＋LC的形态和数量变化可能与其发病密切相关。     

Epidermal Langerhans cell apoptosis is induced in vivo by nonanoic acid but not by sodium lauryl sulphate

Exposure to irritants may cause chronic irritant contact dermatitis (ICD), characterized by irregular epidermal thickening and a predominantly dermal mononuclear cell infiltrate. The mechanisms involved, and why only certain individuals are affected, are not clearly understood. Different irritants may trigger different cellular and molecular interactions between resident skin cells and recruited inflammatory cells. In some individuals these interactions may become self-perpetuating resulting in persistent inflammation in the absence of continued exposure. This study examined Langerhans cell (LC) density in clinically normal skin of 46 patients with chronic ICD and 10 healthy individuals, and compared the action of the two irritants nonanoic acid (NA) and sodium lauryl sulphate (SLS) on the LCs and keratinocytes of clinically normal skin in patients with chronic ICD. There was a higher number of LCs/mm basement membrane in patients compared with controls, although there was no difference in the number of dendrites/LC nor in dendrite length. SLS induced keratinocyte proliferation after 48 h exposure, had no effect on LC number or distribution, and induced keratinocyte apoptosis after 24 and 48 h exposure. In contrast, NA decreased keratinocyte proliferation after 24 h exposure but this returned to basal levels after 48 h, and induced epidermal cell apoptosis after only 6 h exposure. NA dramatically decreased LC number after 24 and 48 h exposure, which was accompanied by basal redistribution and decreased dendrite length. Most significantly, NA induced apoptosis in over half of the LCs present after 24 and 48 h exposure.     

Langerhans cells in squamous cell carcinoma vs. pseudoepitheliomatous hyperplasia of the skin

BACKGROUND: In clinical and histopathological practice, it is sometimes difficult to distinguish pseudoepitheliomatous hyperplasia (PEH) from squamous cell carcinoma (SCC) of the skin. Several studies have shown a low density of Langerhans cells in SCC of the skin, and recent research on cervical SCCs has suggested that the decreased density of dendritic cells is secondary to low E-cadherin expression. SCCs of the head and neck similarly have decreased E-cadherin expression, but E-cadherin expression is preserved in PEH. We hypothesized that PEH of the skin would have an increased number of Langerhans cells compared with SCC. METHODS: We studied immunohistochemical expression of CD1a on paraffin-embedded tissue in 12 cases of SCC and 11 cases of PEH of the skin. RESULTS: The number of Langerhans cells in SCCs vs. PEH was similar; in both types of lesions, the Langerhans cells were decreased in density compared with the normal flanking epidermis. CONCLUSIONS: PEH has a decreased number of Langerhans cells compared with the normal epidermis. As SCCs also have decreased numbers of CD1a-positive cells, this stain is not useful in differentiating these two entities.     

Glucocorticoid receptor localization in human epidermal cells

Glucocorticoids, which are widely used in therapy, exert their immunosuppressive actions through specific receptors. These receptors have been characterized in cultured human skin fibroblasts and keratinocytes, but their localization in vitro and in vivo has not been established. To determine the tissue and cellular distribution of glucocorticoid receptors (GR), two specific polyclonal rabbit anti-human GR antibodies were used to detect these receptors in skin biopsy specimens, in freshly isolated and cultured human epidermal cells and in keratinocyte cell lines. Immunoreactive GR were only faintly detected in normal and abnormal differentiated cells and as well as those in the stratum granulosum and corneocytes. These immunolocalization studies were confirmed by fluorescence cell sorter analysis of isolated basal and suprabasal keratinocytes. Immunoreactive GR were highly expressed in normal cultured human keratinocytes, Langerhans cells and several cell lines whereas they were less expressed in melanocytes. Based upon these results the main targets of glucocorticoids in the epidermis appear to be basal and Langerhans cells. Received: 6 February 1995     

模拟日光照射后皮肤CD1a、CD68阳性细胞变化的研究

目的 观察正常人皮肤经日光模拟器照射（solar-simulated ultraviolet radiation,ssUVR)后,朗格汉斯细胞（Langerhans cells, LC）和CD68阳性的巨噬细胞的变化。方法14名健康汉族女性志愿者于背部非曝光部位接受ssUVR照射。选择2个正方形部位,一处为正常对照,另一处为每日一次ssUVR照射。第4天照射后的72小时,进行活检取材。对所有标本进行CD1a和CD68免疫组化染色。结果 未照射部位正常表皮内的LC密度为258±61个/mm2,ssUVR照射部位的LC密度明显降低为96±53个/mm2,LC的形态不完整,树突变短而不明显。真皮浅层CD68阳性的巨噬细胞,未照射部位密度为290±22个/mm2,ssUVR照射部位的密度升高为399±65个/mm2。经过照射后真皮这些巨噬细胞数目明显增多位置上移,形态上树突变长并且大多数互相连接紧密。结论ssUVR照射可使LC数目减少,形态破损。真皮内的巨噬细胞则增高,这似有助于弥补紫外线照射对局部免疫的抑制作用。     

大疱性类天疱疮患者皮损中CXCR5的表达及意义

目的 检测滤泡辅助性T细胞（Tfh）趋化因子受体5（CXCR5）在大疱性类天疱疮患者皮损中的表达,分析和探讨CXCR5在大疱性类天疱疮发病机制中的作用。 方法 应用免疫组化法检测16例大疱性类天疱疮患者皮损及10例健康人皮肤中CXCR5的表达。 结果 CXCR5在健康人皮肤表达于基底细胞层,主要表达于细胞质、细胞膜处;在大疱性类天疱疮皮损中表达于基底细胞层与棘细胞层。CXCR5在健康人皮肤中阳性细胞表达均数为11.16 ± 4.47,在大疱性类天疱疮患者皮损中为35.70 ± 12.20,两组差异有统计学意义（t = 6.07,P < 0.01）。 结论 CXCR5可能参与大疱性类天疱疮的发病。     

Evaluation of apoptotic cells induced by ultraviolet light B radiation in epidermal sheets stained by the TUNEL technique

Two major components of epidermal cells, keratinocytes and Langerhans cells, are injured by ultraviolet light B radiation, resulting in sunburn cell (apoptotic cell) formation, impaired function, and a reduced number of Langerhans cells. Quantitative analysis of Langerhans cell damage is usually performed using epidermal sheets, whereas that of keratinocytes has been performed by counting the number of sunburn cells in vertical tissue sections. In this study we assessed the influences of ultraviolet light B radiation on epidermal cells by apoptotic cell formation, using murine epidermal sheets stained by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling technique. Ten to 75 mJ per cm2 of ultraviolet light B radiation induced apoptotic cells in abdominal skin of C3H mice. The cells were induced in 6 h after 50 mJ per cm2 of ultraviolet light B irradiation with the peak in number in 24 h, 18.8 +/- 5.0 per mm2 and 97.7 +/- 7.4 per mm2, respectively. One week later, the apoptotic cells were not visualized. As C3H/He, BALB/C, and C57BL/6 mice showed almost the same frequency of apoptosis in epidermal sheets from 50 mJ per cm2 ultraviolet light B-irradiated skin, the induction of the cells by ultraviolet light B radiation did not depend on the genetic trait of the mouse. Xeroderma pigmentosum type A gene-deficient mice, however, showed a greater induction of apoptotic cells (216.9 +/- 25.2 per mm2) by ultraviolet light B radiation than xeroderma pigmentosum type A wild-type mice (89.5 +/- 13.6 per mm2) and conventional mice. Pretreatment with a SPF 60 sunscreen agent was quite effective in reducing the induction of apoptotic cells. Using confocal laser scanning microscopy and double staining, 1.5 +/- 2.7% of apoptotic cells were Ia-positive cells in 24 h after 50 mJ per cm2 of ultraviolet light B radiation. Apoptotic Ia-positive cells were not observed 48 h after the radiation. On the other hand, no apoptotic dendritic epidermal T cells were observed in up to 75 mJ per cm2 of ultraviolet light B radiated skin. Thus, nearly all apoptotic cells were keratinocytes, and Langerhans cells and dendritic epidermal T cells appeared resistant to ultraviolet light B-induced apoptosis. Compared with the assessment in vertical tissue sections, the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling technique with epidermal sheets appeared to be a more physiologically relevant method for quantitative evaluation of apoptotic epidermal cells induced by ultraviolet light B radiation.     

Langerhans cell hyperplasia and IgE expression in canine atopic dermatitis

Langerhans cells appear to be critical for IgE-mediated allergen capture and presentation in human atopic dermatitis. The present study sought to determine whether epidermal (i.e Langerhans cells) and dermal dendritic cells in the skin of dogs with atopic dermatitis are hyperplastic and expressed surface IgE. Frozen sections of lesional or nonlesional atopic and normal control canine skin were immunostained with CD1a-, CD1c-, and IgE-specific monoclonal antibodies. The enumeration of cells was performed by morphometry in both the epidermis and the dermis. Cell counts were compared with each individual’s total serum IgE levels. Higher numbers of epidermal and dermal dendritic cells were present in atopic dogs than in normal control animals. Epidermal Langerhans cell counts were significantly higher in lesional than in nonlesional atopic specimens. IgE⁺ dendritic cells were observed in lesional atopic epidermis and dermis, and nonlesional atopic dermis, but not in normal control skin specimens. The percentages of IgE⁺ dendritic cells were correlated with each patient’s total serum IgE levels. These results demonstrate dendritic cell hyperplasia and IgE expression in canine atopic dermatitis. Increased epidermal Langerhans cell counts in lesional specimens suggest an epidermal allergen contact in canine atopic dermatitis.