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Lectin-binding profiles of epidermal Langerhans cells (LCs) were investigated in three strains of mice using immunofluorescence procedures. Three lectin-binding profiles were observed in each strain of mice. Most epidermal LCs reacted with concanavalin A (Con A) and Ricinus communis agglutinin 1 (RCA-1), whereas none reacted with Dolichos biflorus agglutinin (DBA). Peanut agglutinin (PNA) and wheat germ agglutinin (WGA) reacted with some of the epidermal LCs. These binding profiles were similar from site to site of the body in all strains of mice. We also investigated the lectin-binding profiles of epidermal Ia positive (Ia+) cells migrating into the grafted skin up to 165 days after transplantation. BALB/c (H-2d) murine skin was grafted onto the back of (C3H/He x BALB/c)F1 (H-2k x H-2d) mice. The percentages of migrating I-A+ epidermal cells reactive with PNA and WGA were different from those of the normal epidermis soon after grafting and reached a normal level at 43 days after grafting. Our results demonstrated that there is a heterogeneous population of epidermal LCs defined by lectin-binding profiles.

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To understand the role of cutaneous immune cells in host resistance to the induction and growth of skin cancer, we investigated the number and morphology of murine dendritic epidermal cells (dEC) during the evolution of ultraviolet (UVA) UV-induced skin cancers. Female C3H/HeN mice were treated topically with 8-methoxypsoralen followed by ultraviolet A (UVA) radiation 3 times/week or irradiated with UVB radiation 3 times/week. In both psoralen plus UVA- and UVB-treated mice, ATPase+ and Ia+ Langerhans cells almost completely disappeared from the treated skin during the early latency period of tumor development (4 weeks) but reappeared in the epidermis late in the latency period (between 15 and 22 weeks). The ATPase+ cells that reappeared in the epidermis had a rounder, less dendritic morphology than normal Langerhans cells. Thy-1+ dEC were totally depleted from the epidermis in both treatment groups at the end of first week of treatment and were nearly absent from the skin during the entire latency period. After tumors appeared (29 weeks), Thy-1+ dEC were still absent or detected only in small numbers in skin surrounding the tumors. ATPase+ and Ia+ cells present in skin around the tumors constituted 60 to 80% of the number in nonirradiated skin. Mice that received UVA radiation alone developed no tumors. ATPase+ and Ia+ Langerhans cells and Thy-1+ dEC were detected in UVA-treated epidermis after 22 weeks and 43 weeks, although the numbers were lower than those in unirradiated mice. Most psoralen plus UVA-induced tumors (81%) were squamous cell carcinomas, whereas only 24% of UVB-induced tumors were of this histological type. Our results demonstrate that UV-induced skin cancers developed in the presence of ATPase+ and Ia+ cells in the epidermis and in the absence of Thy-1+ dEC.

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The aim of the present work was to characterize the infiltrating cells in fungal diseases of the skin by using immunohistochemical methods. The lesions of superficial mycosis were characterized by a increase in the number of Langerhans cells (OKT6, HLADR+). In the upper dermis more OKT4 cells stained than OKT8, and in the deeper dermis the was a more decreased ratio of OKT4+/OKT8+ cells. On the other hand, the granulomatous reactions of deep mycosis mainly consisted of cells that were labeled positively for lysozyme and alpha 1-antichymotrypsin. In cases with secondary or local immunodeficiency, however, the infiltrating cells wer negative for these enzymes.

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The CD11/CD18 family of leukocyte adhesion-promoting proteins is comprised of three members, each composed of a shared beta subunit (CD18) noncovalently associated with unique alpha subunits (CD11a, CD11b and CD11c respectively). Such three heterodimers, named LFA-1 (CD11a/CD18), H-Mac-1 (CD11b/CD18) and gp150,95 (CD11c/CD18), are involved in mediating leukocyte adhesion in virtually all phases of the immune responses. Since Langerhans cells are regarded as cutaneous leukocytes, we investigated the expression of the members of the CD11/CD18 family on Langerhans cells. A vast series of immunostaining procedures was carried out, using monoclonal antibodies anti-CD11a, -CD11b, -CD11c, and -CD18. Normal skin frozen sections and epidermal sheets were investigated by immunohistology and immunofluorescence; suspended freshly isolated epidermal cells were processed using immunogold techniques, performed in both transmission and scanning electron microscopy, including double labeling procedures and semiquantitative analysis of the labeled cells. The results demonstrated the expression on the membrane of Langerhans cells of the CD11b, CD11c and CD18 antigens, thus indicating that at least both the H-Mac-1 (CD11b/CD18) and the gp150,95 (CD11c/CD18) members of the CD11/CD18 family are detectable on the cell surface of human resting Langerhans cells. Since both such moieties serve as adhesion molecules in (a) cell-cell interactions and in (b) leukocyte migration and localization, the present results suggest that H-Mac-1 and gp150,95 might display a key role (a) in promoting interactions between Langerhans cells and other cells, and (b) in guiding the migration and localization of Langerhans cells.

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Langerhans cell histiocytosis (LCH), or histiocytosis X, is now generally considered to be a non-malignant condition. A flow cytometric (FCM) study of a single case has, however, been published which claimed to provide evidence to contradict this. The presence of DNA-ploidy as detected using this technique is a feature of malignant and pre-malignant disease. In this reported single case, DNA-ploidy was present but the clinical features of this patient were atypical for LCH. We have performed a FCM study of the DNA of nine biopsies of LCH lesions from six patients with well-established disease. In addition, in one of these, fresh tissue studies including the use of an anti-CD I monoclonal antibody to specifically label the LCH cells were performed. In all cases the DNA content of the cells was entirely normal. We therefore found no evidence that LCH is a neoplastic disorder.

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Cyclosporin A (CYA) has recently attracted the attention of the dermatologists with regard to its use in the treatment of severe psoriasis. We report four cases of psoriasis resistant to conventional therapy. Three patients were affected by chronic plaque psoriasis and one by erythrodermic psoriasis. The initial dosage of CYA was 5 mg/kg/day per os, and was gradually reduced according to the course of the disease. The drug was administered for a period of 6 weeks. All patients showed a significant improvement of the clinical picture. No remarkable clinical side effects were observed. During the trial we took skin biopsies on which we conducted histological and immunohistochemical studies. The efficacy of CYA in the treatment of psoriasis demonstrates the important role of the cell mediated immunity in the pathogenesis of psoriasis.

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The surface of dendritic cells from mouse spleen, thymus, and epidermis has been compared with a panel of monoclonal antibodies and the FACS. A method was first developed to isolate populations of large, adherent, thymic dendritic cells that were greater than 90% pure. These were released by collagenase digestion and separated from adherent macrophages after overnight culture. Enrichment was based on the facts that most macrophages remained plastic adherent and rosetted strongly with antibody-coated erythrocytes. As in spleen, thymic dendritic cells were stellate in shape, had abundant class I and II MHC products, lacked many standard macrophage and lymphocyte markers, and actively stimulated the mixed leukocyte reaction. Most spleen and thymic dendritic cells could be lysed by the 7D4 mAb, to the low-affinity IL-2 receptor, and complement but the levels of 7D4 by FACS were low and sometimes not above background. Differences among dendritic cells from different tissues were noted with other mAb. Adherent dendritic cells from thymus all expressed the J11d "B cell" antigen and the NL145 interdigitating cell marker, but lacked the 33D1 spleen dendritic cell antigen. Eighty to ninety percent of spleen dendritic cells were J11d-, NL145-, 33D1+ but the remainder expressed the J11d+, NL145+, 33D1- thymic phenotype. The latter phenotype also was identical to that of epidermal Langerhans' cells. We postulate that the major 33D1+ cell in spleen represents a migratory stage in which dendritic cells are moving from tissues to lymphoid organs.

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In a previous study we observed that human epidermal cell (EC) suspensions containing HLA-DR-expressing keratinocytes showed an amplified T-cell response to purified protein derivative (PPD). To evaluate further the possible immunological importance of class II transplantation antigens on keratinocytes we have compared the T-cell response to PPD in the presence of the following stimulator cells: EC suspensions from normal skin, or EC from tuberculin-reactive skin with or without removal of Langerhans' cells. The proliferation of purified T lymphocytes from peripheral blood in response to PPD in the presence of various concentrations of autologous EC was measured by [3H]thymidine incorporation on day 6. In 3 experiments out of 4 the EC from tuberculin-reactive skin, containing 28-76% HLA-DR-expressing cells as judged by immunocytochemistry (which also revealed fairly numerous HLA-DQ/-DP-expressing keratinocytes and a slight increase in CD36- and CD4- but not CD1-expressing cells), induced a more pronounced T-cell response to PPD than did normal EC. This was not the case in the fourth experiment, in which a small number of HLA-DR-(15%) and few if any HLA-DQ-/-DP-expressing keratinocytes were found. Immunomagnetic removal of CD1-reactive Langerhans' cells from the tuberculin-reactive EC suspensions resulted in a reduction of the T-cell response to PPD, in most cases down to background level (T cells alone + PPD). This study does not support the hypothesis that HLA-DR-expressing keratinocytes can in themselves act as antigen-presenting cells.

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UVB-irradiation during 3 d for 90, 180, and 180 sec, respectively, at a daily dose of 0.1 and 0.2 joule/cm2, respectively, induced slight inflammatory reactions in the mouse ear. The insulin-like growth factor I (IGF-I) immunoreactivity, normally demonstrable only in scattered basal epidermal cells, rapidly increased in intensity and frequency in the epidermis. After 3 d of UVB irradiation almost all epidermal cells were outlined by IGF-I immunoreactivity in their plasma membrane. The Langerhans cells expressed intense IGF-I immunoreactivity throughout their cytoplasm. The elevated IGF-I immunoreactivity ceased after 5-7 d and was normalized in 3 weeks. The number of Ia positive epithelial Langerhans cells did not seem to be affected by UVB irradiation. It is concluded that the increased IGF-I immunoreactivity is likely to reflect formation of the trophic peptide IGF-I, most evidently by Langerhans cells, in early events of the inflammatory, reactive response of the skin to UVB irradiation.

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La célula de Langerhans (C.L.), reconocida actualmente cocmo el brazo aferente más periférico de la respuesta inmune, ubivada en el estrato suprabasal de la epidermis en el ser humano, ratas, cobayos y conejos; no conocemos datos que la hayan demostrado en el armadillo de siete y nueve bandas con técnicas histoquímicas (ATP) asa) o con marcadores monoclonales (OKT 6). En este trabajo se investigó la presencia de las cálulas de Langerhans en la epidermis de 11(once) armadillos, ocho de nueve bandas y tres de siete bandas. Entre los primeros se estudió un caso de Lepra salvaje. Los sitios de las biopsias quirúrgicas fueron la cara ventral de las raíces de los miembros. Se dividió el material en tres partes y hasta el momento sólo se procesó usna parte para láminas epidérmicas marcadas con ATPasa,, según técnica de Wolff y Winkelman modificada, para su cuantificación y estudió morfológico. Hasta la fecha en las once muestras hemos detectado la presencia de las C.L. sin diferencias entre los armadillos de siete y nueve bandas. Tampoco encontramos diferencias significativas entre la Lepra Salvaje y los animales sanos. La morfología difiere en tamaño y forma comparada con las observadas en el cobayo y en el hombre. Son más finas las dendritas más largas pero a veces casi imperceptibles por su escaso grosor. De distribución irregular lo que dificulta de sobremanera su cuantificación, por lo que nos parece prematuro aventurar una cifra para cuantificar esta población celular. En la presentación ejem

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La célula de Langerhans (C.L.), reconocida actualmente cocmo el brazo aferente más periférico de la respuesta inmune, ubivada en el estrato suprabasal de la epidermis en el ser humano, ratas, cobayos y conejos; no conocemos datos que la hayan demostrado en el armadillo de siete y nueve bandas con técnicas histoquímicas (ATP) asa) o con marcadores monoclonales (OKT 6). En este trabajo se investigó la presencia de las cálulas de Langerhans en la epidermis de 11(once) armadillos, ocho de nueve bandas y tres de siete bandas. Entre los primeros se estudió un caso de Lepra salvaje. Los sitios de las biopsias quirúrgicas fueron la cara ventral de las raíces de los miembros. Se dividió el material en tres partes y hasta el momento sólo se procesó usna parte para láminas epidérmicas marcadas con ATPasa,, según técnica de Wolff y Winkelman modificada, para su cuantificación y estudió morfológico. Hasta la fecha en las once muestras hemos detectado la presencia de las C.L. sin diferencias entre los armadillos de siete y nueve bandas. Tampoco encontramos diferencias significativas entre la Lepra Salvaje y los animales sanos. La morfología difiere en tamaño y forma comparada con las observadas en el cobayo y en el hombre. Son más finas las dendritas más largas pero a veces casi imperceptibles por su escaso grosor. De distribución irregular lo que dificulta de sobremanera su cuantificación, por lo que nos parece prematuro aventurar una cifra para cuantificar esta población celular. En la presentación ejem

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This study evaluated the Langerhans cell density in chronically sun-exposed skin (hand) and non-exposed skin (buttock) in subjects that were divided into 4 age groups (20-40; 41-60; 61-80; greater than 81 years). Two markers (OKT-6 and anti-HLA-DR) were used to identify the Langerhans cells (LC), and their count was performed either on epidermal sheets (52 individuals) or skin sections (43 individuals). Three major findings result from this study: 1) there are more LC in the non-exposed skin than in the chronically sun-exposed area; 2) there were no age-related changes in LC counts, and 3) LC co-express the T6 and HLA-DR antigens.

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OK-432, a compound composed of penicillin-G-treated, attenuated Streptococcus pyogenes of human origin, was administered by intratumoral injection (IT) to 15 of 49 patients with Stage III gastric carcinoma, at the time of preoperative endoscopic examination. The 5-year survival rate of patients given IT was 73.3%, whereas the rate was only 36.5% in those not given IT (P less than 0.05). A study of recurrent cases revealed a significantly low incidence of peritoneal recurrence in the group on OK-432 IT (P less than 0.01). In previous work, the authors noted a favorable prognosis of patients with Stage III gastric carcinoma and with a marked infiltration of Langerhans' cells (LC) in the tumor tissues. All of the 49 in the current study were thus examined immunohistochemically, using anti-S-100 protein antibody, the objective being to clarify the relationship between OK-432 IT and the density of LC. The density of LC among those given IT was significantly increased as compared with those not given IT (P less than 0.05). The results of this study suggest that OK-432 IT may lead to augmentation of the density of LC in tumor tissues and hence prevent peritoneal recurrences in patients with Stage III gastric carcinoma.

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Langerhans cells (LC) were identified and quantitated in non-inflamed keratoacanthoma (KA), inflamed KA, non-inflamed squamous cell carcinoma (SCC), and inflamed SCC, by their content of S100 protein. The number of LCs per high-power field was markedly increased in inflamed KA when compared to the other groups. Using similar methods on frozen sections, the expression of HLA-DR was identified on keratinocytes in KA in areas of inflammation but not in other lesions under study. We hypothesize that increased numbers of LCs in inflamed KA are part of the process which results in tumor regression.

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Paraffin sections of 106 primary thyroid carcinomas were the subject of an immunocytochemical study to determine the density of infiltrates of S-100 protein-positive dendritic/Langerhans cells (LC), lysozyme-positive histiocytes, and LCA-positive lymphocytes. Evidence of dense infiltrates of LCs was found only in the majority of papillary thyroid carcinomas (PCs). The determination of the quantity of LCs proved to be a highly effective means of assessing the prognosis of these tumors. Irrespective of other morphologic and clinical features, no single instance of death resulting from cancer occurred among 23 PCs with dense LC infiltrates (including 6 tumors of stage pT4), while 9 of 53 (17%) of the remaining patients ultimately died from thyroid cancer. On the other hand, the degree of histiocytic and lymphocytic infiltrations was not associated with a distinct biologic behavior neither among PC nor among the remaining thyroid carcinomas. These findings suggest that LCs may play an important role in the immunologic defense mechanisms of the host against the tumor only in the papillary type of thyroid cancer.

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The fate of 2,4-dinitrochlorobenzene, a potent contact sensitizing chemical, and 2,4-dichloronitrobenzene, a non-sensitizer, was compared following their application to the skin of BALB/c mice. Although both chemicals were able to bind to protein in vitro and were capable of being absorbed across mouse skin in vivo, only 2,4-dinitrochlorobenzene was able to bind to cells in the skin and to induce the movement of these cells from the epidermis into the dermis and ultimately into the draining lymph nodes. The sensitization potential of a chemical may therefore be dependent on its ability to associate with and stimulate the efflux of cutaneous antigen-presenting cells.

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We describe a flow cytometric technique for measuring the percentage of T6-positive cells in suspensions prepared by trypsinization of human epidermis. The value obtained for healthy controls (1.55 +/- 0.52%) corresponds to about 600 T6-positive cells per mm2 of skin surface, a figure in line with histological estimates. No significant change was found in the percentage of T6-positive cells in either the uninvolved or lesional epidermis of untreated psoriatic patients. PUVA treatment resulted in a significant reduction in T6-positive cells. A cyclic fluctuation in the numbers of T6-positive cells was shown to accompany methotrexate administration on a weekly divided dose schedule.

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Langerhans cells (LC) are bone marrow-derived, Ia+, CD1+, CD4+, ATPase+ dendritic antigen-presenting cells within the human epidermis. Since the CD4 molecule has been implicated as a receptor structure for HTLV-III/LAV (human T-cell leukemia virus/lymphadenopathy-associated virus), we asked whether LC from HTLV-III/LAV-seropositive individuals display signs of HTLV-III/LAV infection. In skin biopsies from 7/40 HTLV-III/LAV-infected persons (1 asymptomatic carrier, 2 patients with acquired immunodeficiency syndrome (AIDS)-related complex and 4 patients with AIDS), LC were the only epidermal cells to react with a monoclonal antibody specific for the HTLV-III core protein p17. A varying percentage of p17+ LC were morphologically altered with blunt dendrites and poorly demarcated cellular contours. In one of these biopsies, the presence of LC-associated viral particles characteristic of HTLV-III/LAV as well as cytopathic changes in approximately one-third of the LC population were demonstrated by electron microscopy. These results strongly suggest that LC may harbor HTLV-III/LAV. The infection of LC with this retrovirus may have deleterious consequences for the immunologic functions of this cell system and may thus contribute to both the acquisition of immunodeficiency and the infectious and neoplastic complications of AIDS.

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A subset of T6 positive cells was recently separated from normal human cord blood mononuclear cells. It was shown to coexpress HLA-DR and myeloid differentiation antigens (Mo1, MY4). The phenotype and ultrastructure of the cells suggested that these T6 positive cells might be the precursors of the Langerhans cells of the skin. We have previously demonstrated by immunogold labeling techniques that the T6 surface antigen of human Langerhans cells of the skin is internalized in unfixed Langerhans cells or indeterminate cells by a process of receptor-mediated endocytosis. This process involved the formation of coated pits, coated vesicles, endosomes and lysosomes. Following this process, in Langerhans cells, gold labeled Birbeck granules appeared in the cell center often in continuity with endosomes. In the present study, we used an indirect immunogold labeling technique to reveal the T6 antigen present on the surface of living T6 positive cord blood mononuclear cells. We observed the internalization of the T6 surface antigen by a process of receptor-mediated endocytosis similar to that described in Langerhans cells of the skin. This process, however, was not followed by the appearance of intracytoplasmic Birbeck granules.

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