The influence of topical dermatological treatment modalities on epidermal Langerhans cells and contact sensitization in mice

The influence of the widely used topical dermatological treatment modalities anthralin, coal tar and pyrogallol on surface markers of epidermal Langerhans cells and contact sensitization was studied and compared with that of a PUVA treatment. A common effect of all dermatological therapies tested was inhibition of Langerhans cell ATPase, whereas an effect on MHC class II antigens was found only after PUVA or tar treatment. The induction of contact hypersensitivity was inhibited only by PUVA, and not by the other treatments. These results show that various forms of topical therapy influence surface markers and immunological function of epidermal Langerhans cells differently.     

Expression of HLA-DR and OKT6 antigens on keratinocytes and dendritic cells in pemphigus

Summary The expression of HLA-DR and OKT6 antigens by epidermal cells in pemphigus was examined by immunohistochemical methods using skin biopsy specimens from human patients with pemphigus vulgaris. Changes in the distribution and subpopulations of Langerhans cells were observed in lesional (involved) skin. HLA-DR-positive, OKT6-negative dendritic cells were numerous and generally confined to the margins of epidermal clefts. OKT6-positive dendritic cells were rare or absent in lesional skin. The HLA-DR-positive, OKT6-negative dendritic cells associated with intraepidermal clefts are most likely functionally active antigen-presenting cells, which may play a role in lesion development. Aberrant expression of HLA-DR molecules by keratinocytes was observed in both involved and uninvolved skin, and may function to facilitate the recognition of surface-bound pemphigus antigen(s) by immunocompetent cells.     

两种类型白癜风患者郎格罕细胞电镜观察

本文对皮节型和泛发型白癜风患者皮肤内郎格罕细胞进行了电镜比较观察。结果表明，两型白癜风患者皮肤内郎格罕细胞均存在着不同程度的形态学改变，以皮节型皮损区更为明显。作者认为白癜风皮肤郎格罕细胞可能受累，但这些改变主要见于皮节型白癜风皮损区。因此目前还难以肯定郎格罕细胞在白癜风发病机制中的作用     

Lymphocyte proliferation test as a diagnostic aid in chromium contact Sensitivity

We investigated the clinical applicability of the lymphocyte proliferation test (LPT) in chromium contact sensitivity. 6 out of 8 chromium-sensitive patients were positive in the LPT, whereas none of 8 non-chromium-sensitive controls responded in vitro to tri- or hexavalent chromium compounds. LPT thus appeared to offer an additional diagnostic tool in chromium sensitivity. We also studied cellular interactions in 4 of our chromium-sensitive patients. Sensitized T-lymphocytes could be activated to proliferate only in the presence of accessory cells, of which epidermal Langerhans cells (LC) appeared more efficient than blood adherent cells.     

Epidermal Langerhans cells,dermal dendritic cells,and keratinocytes in viral lesions of skin and mucous membranes: an immunohistochemical study

Summary We wanted to evaluate the eventual expression of viral antigens and MHC class II products by keratinocytes as well as the alterations of epidermal Langerhans cells and dermal dendritic cells in viral lesions of skin and mucous membranes. Therefore we investigated 68 biopsy specimens of protracted viral lesions, such as warts, condylomas, and mollusca contagiosa, and of rapidly resolving viral lesions such as herpes simplex virus infection. For this we used immunohistochemical staining techniques and several monoclonal and polyclonal antisera. In most cases investigated viral antigens (human papilloma virus antigens or herpes simplex virus type 1 antigens) could be demonstrated in keratinocytic nuclei. Except for a few viral lesions in which epidermal Langerhans cells were rather numerous, epidermal Langerhans cells were reduced in number or absent in almost all viral lesions. Moreover, epidermal Langerhans cells and dermal dendritic cells showed changes in morphology, distribution, and immunophenotype. These alterations may be caused by a toxic effect of the virus on dendritic cells. HLA-DR⁺ keratinocytes could be identified in few viral lesions onlyl HLA-DQ⁺ keratinocytes were not seen. Possible explanations for this lack of MHC class II expression by keratinocytes are discussed.Aspirant of the NFWO (National Fund for Scientific Research)     

Rare case of unifocal Langerhans cell histiocytosis in four-month-old child

Langerhans cell histiocytosis (LCH) comprises a group of disorders, the common feature of which is Langerhans cell proliferation. The clinical presentation is highly varied. The severity and prognosis of the disease are dependent on the type and extent of organ involvement. This paper reports a rare case of a four-month-old white male with unifocal LCH limited exclusively to the mandible, discussing the diagnosis, radiographic and immunohistochemical aspects, treatment and monitoring multidisciplinary of the case.     

ABC免疫光镜及免疫电镜证实硬红斑皮损炎症区郎格罕细胞

应用Ｌｅｕ６、ＨＬＡ－ＤＲ、Ｓ１００抗体ＡＢＣ免疫光镜及免疫电镜方法对ＥＩ皮损内Ｓ１００蛋白阳性组织细胞性质进行了研究。８例ＥＩ免疫光镜观察显示ＥＩ真皮深部及皮下炎症区Ｓ１００蛋白阳性组织细胞其Ｌｅｕ６及ＨＬＡ－ＤＲ染色亦阳性，且多呈树枝状或椭圆形。３例ＥＩ免疫电镜观察显示Ｌｅｕ６十细胞其细胞核是卷曲的脑回状，胞浆内可见不典型的棒状样的郎格罕颗粒，部分阳性细胞超微结构有受损伤的表现。上述结果表明，ＥＩ皮损内所谓的Ｓ１００蛋白阳性组织细胞为ＬＣ，ＬＣ不仅存在于表皮及真皮，亦存在于皮下组织中，且可能介导了ＥＩ细胞免疫的发生。     

长波紫外线对小鼠朗格汉斯细胞生物学活性的影响

目的　研究体外长波紫外线 (UVA)对小鼠表皮朗格汉斯细胞 (LC)生物学活性的影响。方法　观察不同剂量的UVA对BALB/c小鼠表皮LC存活率、膜相关抗原 (Ia、B7 1、B7 2、CD40 )的表达及其抗原提呈功能的影响。结果　生理剂量的UVA (<80kJ/m2 )照射 ,对LC的存活率影响不明显 ,却能增加LC膜抗原的表达 ,促进其抗原提呈功能。超生理剂量的UVA则反之。结论　生理与非生理剂量的UVA对LC会产生不同的生物学效应 ,这可能是UVA调节机体免疫功能的分子基础。