Epithelial Langerhans Research Articles

Tissue distribution of epimucosally applied 3H DNFB: an autoradiographic study.

The distribution of 3H-labeled 2,4-dinitrofluorobenzene (DNFB) has been autoradiographically investigated in buccal mucosa after topical application to sensitized or nonsensitized rats. The rats were killed between 3 min and 24 h after challenge. No significant labeling pattern differences were found between plastic embedded and frozen sections. Surface epithelium was heavily labeled and labeled cells were observed in the lamina propria shortly (3-6 min) after application. These cells were clearly dendritic. Specific accumulation of hapten in epithelial Langerhans cells (LC) could not be clearly demonstrated. The connective tissue labeling gradually diminished and at 24 h post-elicitation, remaining label could be detected only in the epithelial surface layers.

Expression of major histocompatibility class II antigens by Langerhans' cells in cervical intraepithelial neoplasia.

Cervical biopsy samples from 67 patients who had various grades of cervical intraepithelial neoplasia (CIN) or who showed evidence, in the form of koilocytosis, of human papillomavirus (HPV) infection of the uterine cervix, and from 10 women with normal cervices were examined. Cryostat sections from the biopsy samples were stained using monoclonal antibodies to T6, a Langerhans' cell marker, and to major histocompatibility complex (MHC) class II antigens (HLA-DP, DQ, and DR). Epithelial Langerhans' cells were reduced in number and showed changed morphology and distribution in koilocytic lesions and in all grades of CIN (p less than 0.01) except CIN I. HLA-DR expression by Langerhans' cells was significantly increased in koilocytic lesions and in CIN grades I and II (p less than 0.05); HLA-DQ expression was significantly increased in all grades of CIN (p less than 0.05) with the increase being most pronounced in CIN I (p less than 0.01). Columnar epithelium expressed MHC class II antigens in all samples tested and squamous epithelium in four of 29 cases of CIN III. These findings support the view that there is a localised disturbance of immune function in both neoplastic cervical epithelium and that infected with papillomavirus.

Absence of Langerhans Cells in Oral Hairy Leukoplakia, an AIDS-Associated Lesion

Oral hairy leukoplakia (HL) is a recently described manifestation of human immunodeficiency virus (HIV) infection in which Epstein-Barr virus (EBV) has been shown to replicate. To seek evidence for a local defect in mucosal immunity, we assessed the presence of epithelial Langerhans cells (LC) in these lesions and in autologous nonlesional mucosa. We used monoclonal antibodies against HLA-DR, HLA-DQ, and T6 antigens to identify LC in biopsy specimens of HL from 23 homosexual men. In all lesion specimens, LC either were not detected or were present only in greatly reduced numbers with at least 1 of the antibodies. In nonlesional oral mucosa from the same patients, LC were detected with all 3 antibodies in 11/12 specimens (92%) and were found in approximately normal numbers with at least 1 antibody. There was close correlation between the absence of LC and positive staining for EBV, human papillomavirus antigens, and candidal hyphae in the epithelium. We conclude that LC are absent or greatly reduced in the lesions of HL. Absence of normal LC function may be important in the pathogenesis of HL and may reflect an event in the pathogenesis of other features of the acquired immune deficiency syndrome.

Human gingival Langerhans cells in health and disease.

Epithelial Langerhans cells in samples of healthy and diseased gingival tissue were studied using ATPase histochemistry and the monoclonal antibodies OKT6 and anti HLA‐DR. In healthy gingiva Langerhans cells were seen in both oral and sulcular epithelium; they were generally positioned in the basal layers. No Langerhans cells were seen in junctional epithelium. In diseased tissue there was a large increase in the number of Langerhans cells in both oral and sulcular epithelium with many more being situated in the stratum spinosum. There was an increase in the expression of the Class 2 antigen, HLA‐DR, and morphological polarization occurred with dendrites preferentially orientated towards the surface. No Langerhans cells were seen in the pocket lining epithelium of periodontally diseased gingiva.

Change with age in limbal conjunctival epithelial Langerhans cells.

The distribution of Langerhans cells (LC) in corneal and conjunctival epithelial flat mounts obtained from outbred albino Swiss-Webster mice of various ages was examined by histochemical methods. The LC stain positively with ATPase and were negative to DOPA-oxidase. Mouse pup limbal conjunctival epithelium showed one or two LC/mm2. LC began to significantly increase in number by day 31 and ranged from 150-205/mm2 in 7-48 week old mice. A slight decrease in LC was seen in 12 and 24 month old mice.

Zinc iodide-osmium staining of membranecoating granules in keratinized and non-keratinized mammalian oral epithelium

Specimens of keratinized and non-keratinized oral epithelium were examined in the electron microscope after being stained with zinc iodide-osmium. In both types of tissue, reaction was seen in unmyelinated nerves, in the specific granules of epithelial Langerhans cells and within lysosome-like organelles and small vesicles associated with Golgi systems. In keratinized epithelia, the reaction was also present in the membrane-coating granules and between the deepest cells of the keratinized layer. In contrast, the membrane-coating granules of nonkeratinized epithelia lacked Zn iodide-osmium staining despite the presence of reaction in adjacent Golgi systems. It is suggested that Zn iodide-osmium stains glycolipid or glycoprotein material in the cell. This material is elaborated in the Golgi systems from which lysosomes and the membrane-coating granules of keratinized tissues are probably derived.

The influence of vitamin A on epithelial Langerhans' cells of murine buccal and vaginal mucosae.

The influence of vitamin A on epithelial Langerhans' cells of murine buccal and vaginal mucosae.

Expression of ia antigens by murine keratinizing epithelial langerhans cells

Immunofluorescent and immunoelectron-microscopic staining methods were utilized to investigate the localization of Ia antigens in murine keratinizing epithelia. Approximately 3-5% of epidermal cells were shown to be Ia positive. Only dendritic Langerhans cells in the interfollicular epidermis and outer root sheaths were found to express Ia antigens. These Ia determinants were shown to be controlled by both theI- A andI- EC subregions of theH-2 complex. The results were confirmed by identifying positively stained cells containing Langerhans cell granules at the ultrastructural level. No staining was noted on the surface of keratinocytes, melanocytes, or immigrant lymphocytes. The results presented are in close agreement with those previously reported for Ia-bearing Langerhans cells in human and guinea pig epidermis.