Distribution patterns of the OKM 5 antigen in normal and diseased human epidermis

The distribution of OKM 5-positive dendritic cells in the epidermis was investigated in 75 cases of inflammatory dermatoses and in 14 cases of normal human skin by immunohistochemical and morphometric methods. Furthermore 6 cases of normal human skin, 14 cases of nevocellular nevi, 26 cases of malignant melanoma, 7 cases of contact dermatitis and 6 cases of mycosis fungoides have been examined with special emphasis on the expression of OKM 5 antigen on keratinocytes. OKM 5-positive dendritic cells were present in normal human epidermis at a density of 46 +/- 3.4 cells/mm2 section area. However, there was a significant increase in cutaneous drug eruptions (166 +/- 17.2 cells/mm2; U-test: p less than or equal to 0.05). Concerning OKM 5-positive keratinocytes, a mean percentage of 10.2% +/- 5.0% OKM 5-positive keratinocytes was found in nevocellular nevi, compared to 0.5% +/- 0.5% in the adjacent skin. The corresponding values for malignant melanomas were 52.5% +/- 3.4% (lesional epidermis) and 7.1% +/- 2.2% (adjacent epidermis). There were significant differences of both lesional and adjacent epidermis between nevi and melanomas (U-test: p less than or equal to 0.05). Our cases of contact dermatitis revealed a mean percentage of 19.3% +/- 6.7% OKM 5-positive keratinocytes, whereas in mycosis fungoides the corresponding value represents 42.7% +/- 6.2%. The differences between the percentage of OKM 5-positive keratinocytes in normal epidermis and contact dermatitis as well as mycosis fungoides were significant (U-test).(ABSTRACT TRUNCATED AT 250 WORDS)     

Immunohistologic identification of antigen-presenting cells in cutaneous sarcoidosis

Considerable evidence exists to show that activated T lymphocytes preferentially accumulate at sites of disease activity in sarcoidosis. Langerhans cells, which can be recognized by reactivity with an antibody to the T6 antigen are thought to play a primary role in T-lymphocyte activation by the skin, a tissue frequently involved in sarcoidosis. This immunohistologic study examined the distribution of OKT6-positive cells and surface expression of HLA-DR antigen in cutaneous sarcoid lesions. Skin specimens stained with an anti-HLA-DR antibody demonstrated diffuse staining of the granulomas. In addition, keratinocytes, which do not normally express HLA-DR antigens, were found to stain with monoclonal antibody to HLA-DR in an intercellular pattern. Examination of specimens for OKT6-reactive Langerhans cells revealed significantly greater concentrations in the epidermis overlying sarcoidal granulomas (33 +/- 7 cells/mm) than in the epidermis of age-, sex-, and race-matched controls (11 +/- 3 cells/mm, p less than 0.001). Of greater importance was the demonstration that significant numbers of OKT6-positive cells were present within the dermal sarcoid granulomas (19-208/mm2) in a distribution that paralleled that of Leu-3a-positive T lymphocytes. These data suggest that the epidermis may participate in activation of lymphocytes in cutaneous sarcoidosis, and implicate OKT6-positive cells in granuloma formation.     

Quantitative studies on nonlymphoid mononuclear cell subpopulations in cutaneous infiltrates. I. Stage-related changes of dendritic nonlymphoid mononuclear cells, Langerhans' cells, and macrophages in lichen planus lesions

In previous investigations on lichen planus, we suggested that in early lesions T4-positive cells might be antigen-specifically driven, whereas in late lesions T8-positive cells may be cytotoxic to keratinocytes. To verify this hypothesis, we investigated the following nonlymphoid mononuclear cell subpopulations in early versus late lichen planus lesions: interdigitating cells (phenotype: S100-positive, lysozyme-negative, T6-negative, M3-negative), Langerhans cells (phenotype: S100-positive, lysozyme-negative, T6-positive, M3-negative), macrophages (phenotype: S100-negative, lysozyme-positive, T6-negative, M3-positive). Interdigitating cells were moreover identified in semithin and ultrathin sections by distinctive morphological characteristics. The S100-positive/lysozyme-positive cell ratio was higher (p less than 0.01) in early lesions than late lesions. In dermis but not in epidermis (NS), of early lesions, T6-positive cells were less represented than S100 positive cells (p less than 0.025). Thus, Langerhans' cells largely predominated over interdigitating cells in epidermis, but the two populations were both represented in dermis. Lysozyme-positive and M3-positive cells, more abundant in late lesions than in early lesions (p less than 0.001), were often filled with pigment granules.     

T-cell clones with L3T4-positive or Lyt-2-positive phenotypes responding to mutant MHC class II antigen and inducing graft versus host reaction

Two types of T cell clones responding to mutant major histocompatibility class II antigen (Iabm12) were established from spleen cells of C57BL/6 mice: one was L3T4-positive and the other Lyt-2-positive. These two types of clones carried functionally different properties. Lyt-2+ clones were absolutely dependent on exogenous interleukin-2 for their proliferation, whereas some L3T4+ clones secreted interleukin-2 and proliferated autonomously. Both types of clones had cytotoxic activities to bm12 target cells, and Lyt-2+ clones showed stronger activities than L3T4+ clones. Lyt-2+ clones induced induration in situ, whereas the L3T4+ clones induced ulcerative reaction when injected intradermally into mice. Histologically, the L3T4+ clones caused necrosis of the epidermis or upperdermis, while the Lyt-2+ clones induced infiltration of small round cells through the epidermis to the subcutaneous tissues and caused thickening of the epidermis. These characteristic reactivities might be due to a difference in lymphokines produced by each type of T cell subset in response to Iabm12 antigen.     

Increased number of OKT6-positive dendritic cells in the hair follicles of patients with alopecia areata

In 6 patients with untreated alopecia areata in the progressive stage, 6 in the stationary stage, and 6 normal individuals as controls, an in situ analysis of OKT6-positive dendritic cells in hair follicles, and peribulbar and intrabulbar infiltrates was performed using the avidin-biotin-peroxidase method with monoclonal antibodies. In controls, OKT6-positive dendritic cells were distributed only in the upper portions of hair follicles and were not observed in the bulbar area, and the percentage of these cells among all epithelial cells of the hair follicles was 1.0 +/- 0.1% (mean +/- SE). In stationary-stage patients, the distribution and the percentage of positive cells were the same as those for the controls (1.1 +/- 0.1%). In the progressive stage, however, positive cells were distributed in both the upper portions of the hair follicles and the bulbar area, and the percentage of positive cells (4.9 +/- 0.3%) was significantly higher than that of controls. Staining for T, B lymphocytes and T cell subsets in the peribulbar infiltrates revealed a predominance of OKT4-positive cells (the OKT4/OKT8 ratio was from 3:1 to 4:1). This indicates that the number of OKT6-positive dendritic cells increases in the hair follicles of progressive alopecia areata and that these cells may play an important role in cooperation with T cells in the pathogenesis of alopecia areata.     

A comparative immunohistochemical study of adult T cell leukemia and cutaneous T cell lymphoma

An immunoperoxidase study of 2 cases of adult T cell leukemia (ATL) and 2 cases of mycosis fungoides (MF) was done using monoclonal antibodies. In ATL, many anti-interleukin-2 receptor antibody (LeuIL-2R)-positive cells were seen in the dermis and occasionally in the epidermis. In contrast, in MF, LeuIL-2R-positive cells were much less frequent. LeuIL-2R-positive cells in MF may be non-malignant T cells; not all LeuIL-2R-positive cells may be malignant in ATL. These non-malignant LeuIL-2R-positive cells, we suggest, are involved in the interaction between malignant T cells and reactive infiltrating cells. Furthermore, in addition to OKT6-positive cells, OKM1-positive cells were seen in the infiltrates in the dermis in both ATL and MF. OKM1-positive cells also participate in the mechanism of the skin affinity in ATL and cutaneous T cell lymphomas.     

In situ identification of T6-positive cells in normal human dermis by immunoelectron microscopy*

Monoclonal anti-T6 antibody, which reacts with the majority of cortical thymocytes but not peripheral T cells, also reacts with human epidermal Langerhans cells, as shown by a four-step immunoperoxidase method and immunoelectron microscopy. To define whether T6-positive cells are also present in normal human dermis, we used these techniques to demonstrate two immunologically distinct populations of histiocyte-like cells in normal human dermis. The first population contains cells devoid of phagolysosomes or Birbeck granules. These cells react with anti-T6 antibody, but not with monoclonal anti-T3 antibody which defines peripheral T cells, and are found predominantly in and around dermal lymphatic vessels. The second is composed of phagolysosome-containing cells which do not react with anti-T6 antibody or anti-T3 antibody. Because to date, Langerhans cells are the only cells in normal human epidermis that react with anti-T6 antibody, these data provide immunological evidence for a specific link between Langerhans cells and a T6-positive dermal mononuclear cell, possibly the so-called indeterminate cell. In addition, application of these techniques should, for the first time, permit the immunological distinction of these T6-positive mononuclear cells from other cells bearing la antigens, such as dermal histiocytes and certain lymphocytes, in normal and diseased skin.     

蕈样肉芽肿皮损和淋巴结病变中OKT6阳性细胞的观察

本文应用免疫荧光技术及单克隆抗体OKT6对9例覃样肉芽肿皮肤及淋巴结病变进行了观察.在MF皮损的表皮内OKT6阳性细胞分布不规则.有些部位可见OKT6阳性细胞灶性增多,但表皮萎缩、液化变性或破坏区域,其数目仍减少,其中有些形态有不同程度的变化,甚至破碎.在Pautrier小脓肿内也可见树突状OKT6阳性细胞.真皮上部也有不少OKT6阳性细胞,有些聚集成簇.在淋巴结病变中,也发现许多OKT6阳性细胞,其中有些呈卵圆形而无树状突起.     

Tumor-infiltrating T cells in primary cutaneous B-cell lympho-proliferative disorders

BACKGROUND: Tumor-infiltrating lymphocytes (TILs) are considered to play an important role in the antitumoral immune response. The presence and percentage of CD8-positive tumor-infiltrating T cells have been shown to correlate with differentiation and prognosis in various neoplasms. The aim of this study was to determine the number of CD8-positive T cells in various primary cutaneous B-cell lymphoproliferative disorders and to evaluate its correlation with the histological type of tumor. METHODS: Fifty-three lesions were examined by immunohistochemistry with antibodies targeting CD3, CD4, CD8 and TIA-1. Thirty-two lesions had been diagnosed as primary cutaneous B-cell lymphomas (CBCL) and 21 as B-cell pseudolymphomas (B-PSL). CBCLs included 15 follicular lymphomas (FL), 6 marginal zone lymphomas (MZL), and 11 diffuse large B-cell lymphomas (LCL). The number of CD8-positive cytotoxic T cells was determined by computer-assisted morphometrical microscopy. RESULTS: No significant difference could be detected in the density of CD8-positive T cells in B-PSL (101/105 microm(2)), FL (110/105 microm(2)), and MZL (122/105 microm(2)). In contrast, the number of CD8-positive cells (55/105 microm(2)) in LCL was significantly lower (p<0.01) compared to B-PSL, FL and MZL. CONCLUSIONS: In summary the number of CD8-positive T cells in B-cell lymphoproliferative disorders differs in regard to tumor type and differentiation with lowest numbers in diffuse large B-cell lymphomas. However, due to an overlap of the number of TILs, this parameter cannot be employed as a diagnostic parameter for individual cases.     

Immunohistochemical Studies of Infiltrating Cells in Early and Chronic Lesions of Psoriasis

The expression of surface antigens on infiltrating cells, epidermal keratinocytes, and dendritic cells in biopsy specimens from 31 patients with psoriasis was examined immunohistochemically. The specimens were divided into early-phase and chronic-phase groups and then examined in a double blind manner. Among the infiltrating cells in the epidermis, CD4-positive cells were dominant in the early phase; CD8-positive cells were dominant in the chronic phase, resulting in a markedly decreased CD4/CD8 ratio in the latter. On the other hand, among the infiltrating cells in the dermal papillae, CD4-positive cells were dominant in both the early and chronic phases; both CD4-positive and CD8-positive cells were more dominant in the chronic phase than in the early one. However, the CD4/CD8 ratios were decreased in both the dermal papillae and the epidermis in the chronic phase. CD1-positive dendritic cells (probably Langerhans cells) were more numerous in the chronic phase than in the early phase. There were no significant differences between the early and chronic phases with regard to the expression of HLA-DR and HLA-DQ antigens on the infiltrating cells. However, the HLA-DR antigens and ICAM-1 (intercellular adhesion molecule-1) were more strongly expressed on epidermal keratinocytes in the chronic phase than in the early phase. LFA-1α (lymphocyte function-associated antigen-1α)-positive cells were also significantly more numerous in the chronic phase than in the early one, consistent with the expression of HLA-DR antigens and ICAM-1 on keratinocytes mentioned above. On the other hand, VLA-4 (integrin α₄β₁) positive cells were expressed more abundantly in the epidermis in the early phase than in the chronic phase. These results suggest, first, that the chronic phase of psoriasis is as immunologically active as or more active than the early phase. Second, CD4-positive T cells are more important than CD8-positive T cells in the early phase of psoriasis; CD8-positive rather than CD4-positive T cells are more important in the chronic phase. Third, the LFA-1/ICAM-1 pathway may play an important role with regard to cell adhesion of the infiltrating cells in the psoriatic lesions in disease exacerbation or prolongation, whereas the VLA-4/VCAM-1 (vascular cell adhesion molecule-1) pathway may be more important in disease onset.     

Inflammatory cell types in normal human epidermis--an immunohistochemical and morphometric study

Inflammatory cells in 15 specimens of normal human epidermis were selectively stained by a monoclonal antibody immunoperoxidase technique. The quantitative assessment using an interactive image analysis system revealed OKT 11 positive cells (T lymphocytes) and Leu 2a positive cells (suppressor/cytotoxic cells). As there was no significant difference in the distribution of these markers, helper/inducer cells obviously are not present in considerable amounts. OKM 5 positive cells outnumbered OKM 1 positive cells, indicating the presence of a OKM 5+, OKM 1-macrophage subset. The epidermal dendritic cells clearly showed a striking heterogeneity regarding the expression of HLA-DR (62% of OKT 6-positive cells) and Leu 3a (47%), suggesting the existence of immunologically distinct subsets of human epidermal dendritic cells.     

Multiparameter flow cytometric characterization of epidermal cell suspensions prepared from normal and hyperproliferative human skin using an optimized thermolysin-trypsin protocol

Reliable flow cytometric analysis of normal and diseased skin requires pure epidermal single-cell suspensions. Several methods to separate the dermis from the epidermis are available. The proteolytic enzyme thermolysin separates the epidermis from the dermis at the lamina lucida and therefore permits reliable dermoepidermal separation. In the present study an optimized cell isolation procedure using thermolysin and trypsin is described, which is particularly suitable for punch biopsies. A 16–20-h (overnight) incubation of biopsies taken from normal and hyperproliferative skin with thermolysin (0.5 mg/ml) at 4°C produced a selective separation of the dermis and epidermis. After a 30-min trypsin incubation (0.25 mg/ml) at 37°C a cell suspension was produced which was characterized by minimal cell damage (cellular debris and clumps), a high recovery of basal cells and high quality DNA histograms. Furthermore, dermal contamination was very low. The thermolysin-trypsin separation methodology followed by triple-labelling flow cytometry provided a precise quantification of the percentage of keratin 10-positive cells, vimentin-positive cells and cells in S and G₂M phases. Proliferative activity was selectively measured in the basal, the suprabasal and the non-keratinocyte compartment at various time intervals during epidermal regeneration after adhesive tape stripping. In contrast to the non-keratinocytes, the percentage of cells in S and G₂M phases in the basal keratinocytes and in the suprabasal compartment increased 44–48 h after stripping. The increased proliferation following tape stripping was paralleled by an increased invasion of vimentin-positive cells into the epidermis and preceded by a decreased number of keratin 10-positive cells. Thermolysin-trypsin separation followed by three-colour flow cytometry permits a highly selective characterization of normal and hyperproliferative epidermis.     

Plane warts under spontaneous regression. Immunopathologic study on cellular constituents leading to the inflammatory reaction

Immunohistologically, cellular infiltrates in regressing plane warts were mainly composed of lymphocytes and mononuclear phagocytes. There were many infiltrating T lymphocytes. Immunoelectron microscopic observation demonstrated that both helper/inducer and suppressor/cytotoxic phenotypes of T lymphocytes infiltrated in the lesions. OKT6-positive cells were observed in the dermis as well as in the epidermis. Moreover, as noted in allergic contact dermatitis, the apposition of T lymphocytes to Langerhans' cell-like cells could be seen. Lymphocytes and a small number of mononuclear phagocytes were found adjacent to damaged keratinocytes in the epidermis, the picture of which has been described as satellite cell necrosis, a hallmark of cytotoxic reaction by aggressors. These findings suggest that specific cell-mediated immunity against virus-infected keratinocytes takes place in the process of regressing plane warts.     

Immunophenotyping of the eczematous flare-up reaction in a nickel-sensitive subject

An eczematous flare-up reaction, occurring at a previously involved site, which followed oral challenge with 5.6 mg of nickel in a 29-year-old nickel-sensitive woman, was biopsied and studied by immunohistochemistry. The cellular infiltrate in the dermis and epidermis at 8 days was predominantly of Leu 3a phenotype (helper/inducer T lymphocytes), with smaller numbers of Leu-2a-reactive (suppressor/cytotoxic) T lymphocytes. Many infiltrating cells were DR-positive. No increase in epidermal Leu-6-positive Langerhans cells was seen but Leu-6-reactive cells were noted in the dermal infiltrate. Keratinocytes showed some expression of class II antigen (mainly DR). In comparison with the 48-hour allergic patch test reaction, the eczematous flare-up site showed no increase in epidermal Langerhans cell numbers nor infiltration with macrophages, but the responses were similar since both showed a superficial T cell reaction in the skin.     

An immunohistochemical and immunoelectron microscopic study of the ontogeny of rat Langerhans cell lineage with anti-macrophage and anti-Ia monoclonal antibodies

An immunohistochemical study with anti-macrophage and anti-Ia monoclonal antibodies was performed to clarify the relationship between Langerhans cells (LC) and indeterminate cells (IC) in rat epidermis both in adulthood and in the fetal stage. On immunoelectron microscopy, a mouse anti-rat macrophage monoclonal antibody, TRPM-1, recently produced by us, reacted with IC and some LC in adult rat skin. Ontogenic study revealed that TRPM-1-positive cells first appeared in the epidermis of fetal rat heads on Day 17 of gestation and then spread caudally along the anterior-posterior axis. On Day 20 of gestation, when the distribution of the TRPM-1-positive cells over body surface became even, Ia-positive cells appeared in the epidermis and began to increase in number. Ia-positive cells with Birbeck granules were found on Day 21 of gestation. These results indicate that. TRPM-1-positive IC matured into Ia-expressing LC after being exposed to microenvironmental change during the perinatal period. The number of Ia-positive cells exceeded that of TRPM-1-positive cells at around 5 d after birth. Afterwards, there were more dendritic Ia-positive cells found in the interfollicular areas than TRPM-1-positive ones. However, local concentrations of the TRPM-1-positive IC in the follicular infundibula were frequently found in the fetal stage and occasionally in adulthood. These TRPM-1-positive cells in the follicular infundibula were thought to be a precursor pool in the epidermis for LC.     

MON-150, a versatile monoclonal antibody against involucrin: characterization and applications

Summary A monoclonal antibody, designated MON-150, was found serendipitously to react strongly with the granular layer of normal human epidermis and with the upper spinous layers of psoriatic epidermis. From analysis by flow cytometry of cultured human keratinocytes, it appeared that the percentage of MON-150-positive cells strongly increased when the cells reached confluence and the growth fraction declined. To identify the antigen recognized by MON-150, a lysate of human keratinocytes was subjected to affinity chromatrography using a MON-150 Sepharose column. This yielded a single protein of approximately 350 kDa as measured on Superose 6 FPLC gel permeation chromatography using nondenaturing conditions. In Western blot analysis under denaturing and reducing conditions, a 140-kDa protein was detected. The subcellular localization and the molecular weight of the antigen recognized by MON-150 suggested that the antigen involved might be involucrin. This was confirmed using a commercial polyclonal antiserum against involucrin. We conclude that MON-150 is a new, versatile antibody against human involucrin.     

Accessory and adhesion molecules expressed on murine epidermal Langerhans cells and the modulation by cytokines.

Langerhans cells (LC) are MHC class II (Ia)-positive dendritic cells that act as an antigen-presenting cells for T cell-dependent immune responses. LC originate from cells in bone marrow and migrate into the epidermis through blood vessels. LC also migrate from the epidermis to regional lymph nodes after antigen stimulation where they present antigens to T cells. These are the essential features of LC. The morphological and functional properties of LC are modulated by external stimuli or various cytokines. In this review we focus on the accessory and adhesion molecules on LC and describe how these molecules are modulated by cytokines. We also describe the molecules participating in the migration of LC into and from the epidermis. Moreover, we introduce our data obtained from purified murine epidermal LC and from the transgenic mice overexpressing several cytokines in the epidermis.     

T cell subsets and Langerhans cells in lichen planus: in situ characterization using monoclonal antibodies

Skin biopsies from four patients with lichen planus were studied using monoclonal antibodies directed against T lymphocytes. Anti-T1 and anti-T3 antibodies, which react with all peripheral T cells, stained most cells in the dermal infiltrates. The majority of infiltrating cells also stained with anti-T4 and anti-T4b antibodies, which react with helper/inducer cells, whereas a minority of cells stained with anti-T8 antibody, which reacts with cytotoxic/suppres-sor cells. Surface IgM was not identified on any infiltrating cells, providing evidence against B cell participation. Intraepidermal and dermal cells with long cytoplasmic extensions stained with anti-T6 antibody in all cases, defining them as Langerhans cells or their precursors. T6-positive cells were seen in greater number than in normal control epidermis and dermis. The results indicate that well-developed lesions of lichen planus are characterized by an influx of helper/inducer T lymphocytes and increased numbers of Langerhans cells. These observations support the contention that cellular immunity is important in the pathogenesis of this disorder.     

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.