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.     

The ICAM-3/LFA-1 interaction is critical for epidermal Langerhans cell alloantigen presentation to CD4+ T cells

Intercellular adhesion molecule (ICAM)-3 is a recently described member of the immunoglobulin superfamily and, as such, is closely related to ICAM-1 and ICAM-2. All three ICAMS are cognate for the counter-receptor lymphocyte function associated antigen-1 (LFA-L CD11a/CD18). Unlike ICAM-1 and ICAM-2. ICAM-3 is constitutively expressed at high levels on resting leucocytes. We investigated the expression and function of ICAM-3 in normal skin (n= 5), as well as its expression in psoriasis (n= 4). atopic eczema (n= 4), allergic (rhus) contact dermatitis (n=3). and cutaneous T-cell lymphoma (CTCL. n=2). Five-micrometre cryostat sections of skin were stained using monoclonal antibodies to ICAM-3 and A well characterized immunoperoxidase technique. In normal skin. ICAM-3 was expressed by all cutaneous leucocytes hut most striking was the strong expression of ICAM-3 by Langerhans cells within both epidermis and dermis. This observation was confirmed by double-labelling with CD1a and negative staining with an IgG1 isotype control. In psoriasis, atopic eczema, allergic contact dermatitis, and CTCL. ICAM-3 was co-expressed on all CD1a⁺ cells, although, in psoriasis, the intensity of ICAM-3 expression was reduced. Functional blocking experiments were performed to determine whether the observed ICAM-3 expression on Langerhans cells was functionally important in antigen presentation. CD4⁺ T cells were prepared from peripheral blood and 10⁵ CD4⁺ T cells combined with 10⁵ epidermal cells harvested from keratome biopsies of normal skin of an individual allogeneic to the T-cell donor. Addition of 50 μg anti-ICAM-3 to the co-culture resulted in a consistent (50%) reduction in degree of alloantigen presentation by Langerhans cells to T cells. Inhibition was 77% of that produced by the addition of anti-LFA-1. These data indicate that ICAM-3 is constitutively expressed by Langerhans cells and is a major ligand for LFA-1 on CD4⁺ T cells during their response to Langerhans cells. Because fresh Langerhans ceils constitutively express little ICAM-1. whereas ICAM-3 is constitutively expressed at high levels, it would appear that 1CAM-3 is the dominant functional ICAM on in situ Langerhans cells in the normal epidermis.     

In situ expression of the costimulatory molecules CD80 and CD86 on Langerhans cells and inflammatory dendritic epidermal cells (IDEC) in atopic dermatitis

Abstract The functional expression of costimulatory molecules on antigen-presenting cells may be a key event in the pathogenesis of atopic dermatitis (AD). Recently, the expression of CD86 (B7-2/B70) has been demonstrated on CD1a⁺ epidermal dendritic cells (DC) in AD lesions by immunohistological and functional analysis. Therefore, we sought to further characterize the in situ expression of costimulatory molecules on these cells, considering the two subpopulations of (1) CD1a⁺⁺⁺/CD11b^– Langerhans cells (LC) containing Birbeck granules and (2) CD1a⁺/CD11b⁺⁺⁺ inflammatory dendritic epidermal cells (IDEC), devoid of Birbeck granules, from AD and other inflammatory skin diseases. Flow cytometry, skin mixed lymphocyte reactions (SMLR) and immunohistological analysis were performed, and showed that IDEC and not LC are the relevant cells expressing the costimulatory molecules CD80 and CD86 in situ. This expression varied with the underlying diagnosis, with AD showing the highest expression of both CD80 and CD86 in situ. Furthermore, the expression of CD80, CD86 and CD36 were significantly correlated. With short-term culture, both CD80 and CD86 were further upregulated on LC and IDEC. Finally, anti-CD86 antibody reduced the stimulatory activity of epidermal DC. These results indicate that costimulatory molecules on LC and IDEC might play a role in the pathogenesis of AD. Received: 7 June 2000 / Accepted: 21 January 2001     

In situ immunophenotyping of antigen presenting cells and T cell subsets in atopic dermatitis

Twelve patients with classical adult-type atopic dermatitis were biopsied from clinically active lesions. An extended panel of monoclonal antibodies which define immunocompetent cell subsets was used to immunophenotype the epidermal and dermal inflammatory cells present in situ. The dermis showed an impressively high T₄/T₈ ratio. Epidermal Langerhans cells were irregularly distributed and showed morphological alterations. Langerhans cells were only sporadically observed in layers deeper than the papillary dermis. A surprisingly high number of cells with the immunophenotype (RFD1 +, HLA-DR+) of interdigitating cells was seen both in the epidermis and in the dermis. Monocytes, B cells, plasma cells and natural killer cells were only sporadically found. Active subacute adult atopic dermatitis was thus found to be mainly characterized by a remarkable high, in situ, T₄/T₈ ratio and a dermal preponderance of antigen presenting cells with the phenotype of interdigitating cells and to a lesser extent, Langerhans cells.     

Interferon-gamma differentially regulates CD80 (B7-1) and CD86 (B7-2/B70) expression on human Langerhans cells

CD80 (B7-1) and CD86 (B7-2/B70) have recently been identified in cultured human Langerhans cells (LCs), although their role and regulatory properties remain unclear. We present our comparison of the expression of the molecules, mRNAs and the function between CD80 and CD86 in human LCs treated by interferon γ (IFN_-γ). We examined the regulatory properties of CD80 and CD86 expression in human LCs pretreated with IFN_-γ. Flow cytometric analysis indicated that the mean fluorescence intensity of CD86 but not CD80 was enhanced. However, the percentage modulation of both CD80 and CD86 positive cells were significantly up-regulated in a dose-dependent manner, after 48-h culturing with IFN_-γ. The regulatory properties of CD80 and CD86 mRNA expressions in human LC were studied using polymerase chain reaction methods. We found that both CD80 and CD86 mRNA of enriched LCs following IFN_-γ pretreatment for 12 h were higher than those without pretreatment. We have demonstrated that the primary allogeneic mixed epidermal cell-lymphocyte reaction induced by human LCs treated by IFN_-γ increased in a dose-dependent manner. There was a 61.5% inhibition by anti-CD86 monoclonal antibody and a 32.5% inhibition by anti-CD80 monoclonal antibody. These data indicate that the CD80 and CD86 expression of human LCs may be differently regulated by IFN_-γ.     

The importance of CD54 and CD86 costimulation in T cells stimulated with Candida albicans and Dermatophagoides farinae antigens in patients with atopic dermatitis

Abstract A number of studies have demonstrated an increased frequency of allergen-specific T cells producing increased amounts of interleukin-4 (IL-4) and IL-5, but little interferon-γ in both the peripheral blood and skin lesions of patients with atopic dermatitis (AD). In this study, to further clarify the characteristics of T cells obtained from AD patients, we examined the dependency of the antigen-specific proliferation of peripheral blood mononuclear cells (PBMC) from AD patients on costimulatory molecules. The antigens used were Candida albicans and Dermatophagoides farinae, for which AD patients show increased levels of IgE antibodies. PBMC from control healthy donors stimulated with these antigens incorporated [³H]-thymidine much more than PBMC from AD patients. The addition of anti-CD54, -CD40, -CD80 and -CD86 monoclonal antibodies to the cultures showed that the PBMC required only CD54 and CD86 for stimulation with C. albicans, but required CD54, CD80 and CD86 for stimulation with D. farinae. Among these monoclonal antibodies, the anti-CD54 antibody suppressed the proliferative responses of most PBMC, most effectively followed by the anti-CD86 antibody. However, there were no significant differences in the requirement for costimulatory molecules of PBMC proliferation stimulated with C. albicans or D. farinae between AD patients and healthy donors. Since many studies have suggested that T-helper type 1 and T-helper type 2 immune responses are different in their dependency on CD80 or CD86 costimulation, our present results suggest that the allergen-specific T cells of AD patients are not completely shifted to a T-helper type 2 subset. Received: 10 February 1998 / Received after revision: 2 July 1998 / Accepted: 2 July 1998     

Visualization and characterization of migratory Langerhans cells in murine skin and lymph nodes by antibodies against Langerin/CD207

Dendritic cells are professional antigen-presenting cells that initiate primary immunity. Migration from sites of antigen uptake to lymphoid organs is crucial for the generation of immune responses. We investigated the migratory pathways specifically of epidermal Langerhans cells by tracing them from the epidermis to the draining lymph nodes. This was possible with a new monoclonal antibody, directed against murine Langerin/CD207, a type II lectin specific for Langerhans cells. In situ, resident, and activated Langerhans cells express Langerin in the epidermis and on their way through dermal lymphatic vessels. Both emigrated and trypsinization-derived Langerhans cells expressed high levels of Langerin intracellularly but reduced it upon prolonged culture periods. Sizeable numbers of Langerin+ cells were found in skin draining lymph nodes but not in mesenteric nodes. Langerin+ cells localized to the T cells areas and rarely to B cell zones. Numbers of Langerin-expressing cells increased after application of a contact sensitizer. In the steady state, Langerhans cells in the skin-draining nodes expressed maturation markers, such as 2A1 and costimulatory molecules CD86 and CD40. These molecules, CD86 and CD40, were further upregulated upon inflammatory stimuli such as contact sensitization. Thus, the novel anti-Langerin monoclonal antibody permits the unequivocal visualization of migratory Langerhans cells in the lymph nodes for the first time and thereby allows to dissect the relative immunogenic or tolerogenic contributions of Langerhans cells and other types of dendritic cells.     

Expression and functional role of co-stimulatory molecules in CD40+IL-4-stimulated B cells from atopic and non-atopic donors

As immunological dysregulation is a possible key defect in atopic diseases, we have studied the expression and function of costimulatory molecules in atopic dermatitis (AD) patients compared with normal controls. Using flow cytometry, we showed that CD80 and CD86 are expressed at increased levels on human peripheral B cells in both groups after stimulation with anti-CD40 and interleukin 4 (IL-4), but to a significantly higher extent in the AD group. Furthermore, baseline expression of CD80 and CD86 on peripheral B cells was low in normal donors and increased in AD donors. To study the functional role of the costimulatory molecules in CD40+IL-4-stimulated peripheral mononuclear cells from normal and atopic donors, proliferation and IgE production were analysed in the presence of antibodies against the receptors of the costimulatory molecules. In the presence of either anti-CD28 or anti-CTLA-4, cell proliferation and IgE synthesis were significantly enhanced in the atopic group in anti-CD40+IL-4-stimulated peripheral mononuclear cells. These findings suggest that interaction of CD80 and CD86 with their receptors CD28 and CTLA-4 selectively promotes cell activation, including proliferation and IgE production in CD40+IL-4-stimulated peripheral blood mononuclear cells from atopic donors. It remains to be elucidated whether these changes are primary, based on the genetic background of atopics, or whether they are induced secondarily in the context of atopic pathology.     

Autophagy in malnutrition‐associated dermatoses

Malnutrition‐associated dermatoses including necrolytic migratory erythema (NME) and pellagra share common clinicopathological features; in particular, necrolytic changes in the upper epidermis. Here, we report the involvement of autophagy in the development of necrolysis in three patients with malnutrition‐associated dermatoses. First, we examined an autophagy‐specific molecule, microtubule‐associated protein light chain 3 (LC3), using a monoclonal antibody. LC3 was strongly expressed in the granular layers of the active border, and less intensely observed in the perilesional areas. Little LC3 staining or only background levels were observed in control skin diseases including atopic dermatitis (n = 4), psoriasis vulgaris (n = 3), basal cell carcinoma with amyloid deposits (n = 3) and squamous cell carcinoma (n = 3). Electron microscopic observations revealed the presence of autophagosome‐like structures in the necrolytic areas. No apoptotic signals were observed in the necrolytic lesion using the terminal deoxynucleotidyl transferase dUTP nick end labeling method. Epidermal Langerhans cells determined by anti‐CD1a antibody were markedly decreased in number. Our observations suggest the possibility that malnutrition‐associated necrolysis, as exemplified by NME and pellagra, may be induced by autophagy.     

Fc epsilon R11/CD23 receptor distribution in patch test reactions to aeroallergens in atopic dermatitis.

There is increasing evidence that exposure to organic allergens may induce or exacerbate lesional skin in patients with atopic dermatitis. In this study, patients with atopic dermatitis were patch tested to 11 common organic allergens and to control chambers containing 0.4% phenol and 50% glycerin in 0.9% saline. In biopsies from positive patch test reactions, patch test control skin, lesional eczematous and non-lesional skin from atopic individuals, and normal skin from non-atopic volunteers, the presence and distribution of macrophages (RFD7+), dendritic cells (RFD1+), and Langerhans cells, and the expression of the low-affinity receptor for IgE (CD23) were investigated. In patch test reactions and lesional skin samples, inflammatory infiltrates of diffusely distributed macrophages (RFD7+), dendritic cells (RFD1+), T lymphocytes (RFTmix+), and Langerhans cells (CD1+) were seen, the latter being present in both the epidermis and the dermis. The numbers of Langerhans cells were reduced in the epidermis and increased in the dermis in patch test reactions and lesional skin compared to their controls. Double staining revealed a change in the distribution of CD23 antigen. In patch test control and non-lesional biopsies many macrophages and only a few Langerhans cells within the dermal infiltrates expressed this antigen. In patch test reaction and lesional skin samples, however, the proportion of CD23+ dermal Langerhans cells had increased compared to macrophages. Furthermore, in these latter samples an increased proportion of dermal CD1+ cells expressed the dendritic cell (RFD1+) marker. These results show that following antigen challenge there are marked similarities between the phenotype of the cellular infiltrate in patch test reaction and lesional skin biopsies, and also demonstrate a changing distribution of CD23 on antigen-presenting cells.     

Expression of 27 KD, 65 KD and 72/73 KD heat shock protein in atopic dermatitis: comparison with those in normal skin and contact dermatitis

The expression of Heat Shock Protein (HPS) 72/73, HSP65 and HSP27 in skin lesions of atopic dermatitis (n = 21) was studied and compared with that in contact dermatitis (n = 18) and normal skin (n = 9). Keratinocytes in the whole epidermis expressed both HSP65 and HSP72/73 with a membranous, cytoplasmic or nuclear/perinuclear staining pattern much more intensely in atopic dermatitis than in contact dermatitis and normal subjects. In approximately half of the subjects with atopic dermatitis, infiltrating cells in the dermis expressed HSP65 and HSP72/73; this was not observed in contact dermatitis. HSP27 was expressed in the upper epidermis with a cytoplasmic or nuclear/perinuclear staining pattern in all groups. HSP27 was not expressed by infiltrating cells. A clinical evaluation of atopic dermatitis showed that more severe types of atopic dermatitis expressed more intense expression of HSP65 and HSP72/73, but not HSP27, in their skin lesions. These findings suggested that HSP65 and HSP72/73 may play roles in the pathogenesis of atopic dermatitis.     

Expression of CD30 on T helper cells in the inflammatory infiltrate of acute atopic dermatitis but not of allergic contact dermatitis

Abstract  The CD30 molecule has been proposed as a marker for a subset of CD4⁺CD45RO⁺ (memory) T cells with potent B cell helper activity producing IL-5 and IFN-γ and as a specific marker for Th2 cells. Recently, an association has been demonstrated between elevated serum levels of soluble CD30, which is shed by CD30⁺ cells in vitro and in vivo, and atopic dermatitis but not respiratory atopic disorders or allergic contact dermatitis. We studied the expression of CD30 in the inflammatory infiltrate of atopic dermatitis compared with that of allergic contact dermatitis, with special regard to skin disease activity (acute vs subacute/ chronic). Biopsies were obtained from 16 patients suffering from atopic dermatitis (acute n = 6, subacute/ chronic n = 10), from 7 patients with acute allergic contact dermatitis and from 5 positive patch-test reactions. Paraffin-embedded as well as snap-frozen material was stained with anti-CD30 and anti-CD45RO mAbs according to standard procedures. Double-staining procedures for CD30CD3, CD30CD4, CD30CD45RO and CD30CD68 were also performed. Abundant CD45RO⁺ cells were detected both in atopic dermatitis and in allergic contact dermatitis lesions. We found scattered CD30⁺ cells in only one of six formalin-fixed paraffin-embedded acute atopic dermatitis biopsies, but in all of the respective snap-frozen specimens, possibly because CD30 expression on atopic dermatitis infiltrating cells is weak and sensitive to formalin fixation and paraffin embedding. CD30CD3 and CD30CD4 double staining identified CD30⁺ cells to be helper T lymphocytes. No significant CD30 expression (either in paraffin-embedded or in frozen material) could be found in subacute/chronic atopic dermatitis lesions or in any of the specimens of allergic contact dermatitis. The results suggest a specific regulatory function of CD30⁺ T cells in acute atopic dermatitis. With respect to the view that CD30 is a marker for Th2 cells, our observations confirm previous findings that Th2 cells predominate in the infiltrate particularly of acute atopic dermatitis. CD30 expression in acute atopic dermatitis but not in acute allergic contact dermatitis might be helpful in the histological differentiation of these disorders and in the further characterization of atopy patch testing. Received: 1 April 1998 / Received after revision: 28 May 1998 / Accepted: 3 July 1998     

Blockade of costimulatory molecules B7-1 (CD80) and B7-2 (CD86) down-regulates induction of contact sensitivity by haptenated epidermal cells

The hapten, trinitrobenzene sulphonic acid, induced weak B7-1 (CD80) and moderate B7-2 (CD86) expression on Langerhans cells and mRNA expression of both molecules in organ-cultured murine skin. The intradermal injection of hapten-treated epidermal cells induced hapten-specific contact sensitivity in synergic mice. Cells of the keratinocyte cell line, Pam 212, or epidermal cells treated with a mixture of anti-Ia/thy 1·2/γδ antibody plus complement, did not show any sensitizing ability. When hapten-treated epidermal cells were injected into mice after incubation with anti-B7-2 (CD86) or B7-1 (CD80) antibody the resultant contact sensitivity reaction was decreased to less than 50% of the control reaction, a reduction which was similar to that seen with the anti-ICAM-1 and anti-LFA-1 antibody-induced inhibition of contact sensitivity. Anti-B7-1 (CD80) or anti-B7-2 (CD86) antibody also inhibited hapten-specific lymphocyte proliferation or the allogenic mixed lymphocyte and epidermal cell reaction in vitro, although the inhibitory effect of anti-B7-1 antibody was not as significant as that of anti-B7-2 antibody. These results indicate that costimulatory signals induced by a hapten on epidermal Langerhans cells play an important role in the induction of hapten-specific contact sensitivity in mice.     

Effects of pimecrolimus versus triamcinolone on Langerhans cells after UV exposure

Abstract: Background/Purpose: Pimecrolimus is a topical immunomodulator for atopic dermatitis. Concerns regarding malignancy risk resulted in its black box warning in 2006. The purpose of this study is to determine the effects of pimecrolimus on Langerhans cells (LC), mediators of the cutaneous immunity UV‐irradiated skin. Methods: A RCT was conducted investigating pimecrolimus 1% cream vs triamcinolone 0.1% cream on UV‐irradiated epidermal LC on 20 healthy volunteers. Punch biopsies were stained with antibodies to CD1a, HLADR and CD83. Results: Triamcinolone caused more depletion in UV‐irradiated CD1a⁺ epidermis relative to pimecrolimus treatment. (P = 0.030). Using HLA‐DR as a pan‐marker for APCs, pimecrolimus caused marginally less depletion than triamcinolone (P = 0.013). Using anti‐CD83 as a maturation marker, UV‐irradiated skin treated with pimecrolimus showed more mature LC than skin treated with triamcinolone (P = 0.00090). Conclusion: UV‐induced changes in LC are minimally affected by pimecrolimus, compared with triamcinolone.     

Epidermal dendritic cells in psoriasis possess a phenotype associated with antigen presentation: in situ expression of beta 2-integrins.

BACKGROUND: Epidermal dendritic cells (DCs) isolated from psoriasis possess greatly enhanced T lymphocyte-activating properties compared with DCs from normal skin, suggesting that DCs in psoriasis express surface antigens crucial for antigen presentation. These include beta 2-integrins and intercellular adhesion molecule (ICAM)-1. OBJECTIVE: Our purpose was to determine DC phenotype in psoriatic compared with normal epidermis with respect to these molecules. METHODS: Tissue sections were single labeled with a peroxidase antiperoxidase (PAP) immunohistochemical technique and double labeled where necessary with a combination of a PAP and an alkaline phosphatase-anti-alkaline phosphatase technique. RESULTS: In psoriatic compared with normal skin, decreased numbers of DCs expressed CD1a (p less than 0.05), whereas increased numbers of DCs expressed class II major histocompatibility antigens (p less than 0.05). In normal skin positive staining for CD18 was not observed, whereas in psoriasis both CD1a+ and CD1a- DCs expressed beta 2-integrins, LFA-1 (CD11a/CD18), and gp 150/95 (CD11c/CD18). DCs in atopic dermatitis and lichen planus were also found to express beta 2-integrins. Neither MAC 1 (CD11b/CD18) nor ICAM-1 was observed on DCs. CONCLUSION: These data are consistent with either migration of dendritic antigen-presenting cells into the epidermis or in situ cytokine modulation of Langerhans cell phenotype in inflamed skin. Furthermore, they indicate that epidermal DCs in psoriasis and other cutaneous inflammatory diseases express molecules that are known to be crucial for Langerhans cell-driven T-cell activation in vitro.     

IgE-positive epidermal Langerhans cells in allergic contact dermatitis lesions provoked in patients with atopic dermatitis

Summary To see whether or not IgE-bearing epidermal Langerhans cells are specific to skin lesions of atopic dermatitis (AD), we performed immunohistochemical and immunoelectron microscopic examinations of dinitrochlorobenzene (DNCB) contact dermatitis lesions provoked in uninvolved skin of eight patients with AD. In all of the eight examined, IgE-positive epidermal Langerhans cells were observed in the DNCB dermatitis lesions. Typical staining of anti-IgE was absent in the epidermis of normal-appearing skin of five patients with AD. Thus, it is likely that IgE positive epidermal Langerhans cells non-specifically occur in different eczematous diseases provoked in patients with AD.     

Comparative analysis of CD80 and CD86 on human Langerhans cells: expression and function

Abstract Although both CD80 (B7–1) and CD86 (B7–2/B70) have been recently identified in cultured human Langerhans cells (LC), little is known of the role and regulatory properties of CD80 and CD86 on human LC. We present here the results of a study comparing the expression and function of CD80 and CD86 in human LC using the T-helper type-1 cytokines IL-2 and interferon γ (IFN)-γ, and the T-helper type-2 cytokines IL-10, IL-4 and granulocyte/macrophage colony-stimulating factor (GM-CSF). Freshly isolated human LC expressed little CD80 and CD86 in vitro, but the expression of both molecules was rapidly induced during a 72-h incubation with cytokines and the expression of CD86 occurred much earlier and more strongly than that of CD80. The expression of both CD80 and CD86 was upregulated by GM-CSF and downregulated by IL-10, and the expression of CD86, but not that of CD80, was upregulated by both IL-4 and IFN-γ. Finally, pretreatment of LC with GM-CSF and IFN-γ, but not with IL-4, enhanced the alloreactive T-cell proliferation induced by the LC, and IL-10 pretreatment of LC decreased their capacity for alloreaction. These results indicate that the expression of both CD80 and CD86 on human LC may be regulated by these cytokines (IL-2, IL-4, GM-CSF, IFN-γ and IL-10) secreted from helper T cells infiltrating into the inflammatory microenvironment. Received: 4 December 1997     

尖锐湿疣患者外周血单一核细胞共刺激分子CD28,CD40的检测

目的探讨免疫共刺激分子CD28/CD152-CD80/CD86,CD40-CD40L在尖锐湿疣患者外周血单一核细胞(PBMC)中的表达情况。方法采用流式细胞仪(FCM)检测60例CA患者(初发组30例、复发组30例)和30例健康对照者外周血CD28,CD152,CD40L在CD4+,CD8+T细胞上CD80,CD86,CD40在CD19+B细胞上的表达水平。结果CA患者CD28,CD40L在CD4+,CD8+T细胞的表达,与对照组(42.36%,13.85%,5.08%,2.58%)相比,复发组(37.10,11.66%,2.57%,1.25%)较初发组(39.69%,12.76%,3.93%,1.96%)明显降低(P<0.01);CD80,CD86,CD40在CD19+B细胞上的表达与对照组(1.59%,3.83%,14.25%)相比,复发组(0.65%,3.05%,10.24%)较初发组(1.04%,3.45%,12.21%)显著降低(P<0.01),而CD152在CD4+,CD8+T细胞上的表达与对照组(1.71%,9.62%)相比,复发组(39.2%,12.15%)较初发组(2.64%,10.90%)显著增高(P<0.01)。结论尖锐湿疣患者外周血淋巴细胞CD28/CD152-CD80/CD86,CD40-CD40L共刺激分子的异常表达可能与其免疫功能紊乱及复发机制有一定关系。     

Plaque psoriasis vs. atopic dermatitis and lichen planus: a comparison for lesional T-cell subsets, epidermal proliferation and differentiation

BACKGROUND: T-cell infiltration in plaque psoriasis has recently been an important subject of investigation. Interestingly, comparative analyses of the disease-specific composition of the lesional T-cell infiltrate in plaque psoriasis and other inflammatory dermatoses have only sparsely been performed. OBJECTIVES: To compare plaque psoriasis vs. atopic dermatitis and lichen ruber planus with respect to T-cell subsets, epidermal proliferation and keratinization. PATIENTS AND METHODS: Biopsies were taken from untreated lesional skin of patients, six with psoriasis, six with atopic dermatitis and six with lichen planus. T-cell subsets (CD4+, CD8+, CD45RO+, CD45RA+, CD2+, CD25+), an epidermal proliferation (Ki-67) and a keratinization marker (K10) were stained immunohistochemically and quantified using image analysis. RESULTS: The high number of CD8+ T cells (52 +/- 13 cells mm(-1)) found in the psoriatic epidermis was not found in the epidermis of atopic dermatitis (9 +/- 4), nor in the epidermis of lichen planus (34 +/- 10). The other T-cell subsets in the epidermis and dermis showed no statistically significant differences between psoriasis and atopic dermatitis. In contrast to the limited presence of CD4+, CD8+ and CD2+ in the psoriatic dermis (110 +/- 19, 27 +/- 9, 127 +/- 41, cells mm(-1), respectively), more impressive numbers of these cells were observed in the dermis of lichen planus (300 +/- 53, 144 +/- 38, 272 +/- 48, respectively). CD45RO+ memory effector T-cell counts were significantly higher in the epidermis of lichen planus (39 +/- 10) than in psoriasis (19 +/- 5). Psoriatic epidermis proved to have major keratinocyte hyperproliferation (247 +/- 26 cells mm(-1) lamina basalis), as compared with atopic dermatitis (134 +/- 15) and lichen planus (128 +/- 20). Furthermore, a marked decreased expression of keratin 10 was observed in psoriasis (41% of epidermal area) contrary to atopic dermatitis (70%). CONCLUSIONS: Psoriatic epidermis exhibits a pronounced CD8+ epidermotropism with accompanying epidermal hyperproliferation and abnormal keratinization, which changes are only minimally expressed in atopic dermatitis and lichen planus. In plaque psoriasis, substantially fewer activated CD4+ and CD8+ T cells in the dermis and less CD45RO+ T cells in the epidermis are present in comparison with lichen ruber planus.     

Expression of dipeptidyl-peptidase IV (CD26) on CD8+ T cells is significantly decreased in patients with psoriasis vulgaris and atopic dermatitis

T cells play a major role in inflammatory skin disorders such as psoriasis vulgaris and atopic dermatitis. They are both active on the level of cell-to-cell interaction and by the secretion of pro-inflammatory mediators. CD26 is a lymphocyte membrane-associated dipeptidyl peptidase IV (DPP IV), which is able to inactivate chemokines such as RANTES or eotaxin by cleaving dipeptides from the NH2-terminus of proteins. We investigated the expression of CD26 on CD4+ and CD8+ peripheral blood T cells in patients with psoriasis and atopic dermatitis. In addition PASI and SCORAD as a measure of disease severity were determined in each patient at the time of blood drawing. Thirty patients with psoriasis, 15 with atopic dermatitis and 17 age- and sex-matched healthy persons were investigated by two-colour flow cytometry using epitope-specific monoclonal antibodies. Our results revealed, that there is a significant decrease (P<0.05) of CD26 expression on CD8+ T cells in both psoriasis (7.7%+/-3.3, mean and SD, n=30) and atopic dermatitis patients (7.9%+/-3.7, mean and SD, n=15) compared to the control population (11.58%+/-5.0, mean and SD, n=17). However, there was no correlation to disease severity as determined by PASI and SCORAD, respectively. Since CD26 can be regarded as an anti-inflammatory principle the decreased expression in psoriasis and atopic dermatitis patients may lead to a dysbalance in favour of pro-inflammatory mediators in both clinical conditions.