Epidermal lymphocyte chemotactic factor specifically attracts OKT4-positive lymphocytes

Summary Epidermal lymphocyte chemotactic factor (ELCF) from skin overlying a positive tuberculin reaction was compared with the chemoattractants leukotriene B₄ (LTB₄), N-formyl-methionyl-leukylphenylalanine (FMLP), and complement split product C5a (C5a). The chemotactic assay used is a modified Boyden chamber technique. The lymphocytes were subsets of T lymphocytes from healthy young individuals first separated by flotation of E rosettes on Isopaque Ficoll followed by incubation of T cells with anti-CD4 and anti-CD8 monoclonal antibodies and further separation using fluorescence-activated cell sorting. ELCF specifically attracted OKT4+ lymphocytes, while LTB₄, FMLP, and C5a induced significant migration in both OKT4+ and OKT8+ lymphocytes without any clear difference between the various chemoattractants or cell populations. We found no blocking of the chemotactic capacity of ELCF when we added antibodies towards IL-1 and IL-1 to the chemotactic assay. Further recombinant IL-1 and IL-1 did not induce any chemotactic response. Our observations may be of significance in explaining the predominance of OKT4+ cells in allergic contact dermatitis and certain other skin diseases.This work was supported by the Danish Medical Research Council grants no 12-6132 and 12-5691     

A case of malignant haemangioendothelioma treated with recombinant interleukin-2

A case of malignant haemangioendothelioma of the scalp in an 82-year-old female treated with intralesional, intra-arterial and intravenous recombinant interleukin-2 (rIL-2) is reported. The scalp lesions disappeared after injection of 35 350 000 Japan reference units of rIL-2 and excision of the residual tumour. Immunohistochemical characterization of the cells infiltrating the lesion after rIL-2 administration revealed 30–40% CD4⁺ and CD8⁺ T lymphocytes, 20–30% macrophages and 5–10% natural killer cells. These findings are similar to those in other human cancers. Almost all of the cells in the intersticies of the lesion after rIL-2 injection expressed leucocyte function-associated antigen-1, and some of the tumour cells and the infiltrating cells around them expressed intercellular adhesion molecule-1. HLA-DR-positive cells markedly increased in number after rIL-2 administration. This report suggests that rIL-2 administration is the most effective therapy for malignant haemangioendothelioma.     

In situ characterization of lymphocytic immunophenotypes and interleukin-2 receptors in cutaneous tuberculosis and leprosy–a comparative evaluation

The granulomas of lupus vulgaris (LV) were characterized by preponderance of CD4⁺ lymphocytes and a raised CD4⁺/CD8⁺ ratio. In contrast, in scrofuloderma (SF) the CD⁸ T-lymphocyte subpopulation predominated and the CD4⁺/CD8⁺ ratio was significantly decreased. A higher percentage of lymphocytes expressed interleukin-2 receptor (IL-2R) in LV as compared with SF, indicating an activated cellular immune response in the former. Immunophenotypic changes in tuberculosis verrucosa cutis {TBVC) were intermediate between LV and SF. CD4⁺ lymphocytes were the main infiltrating T-cell type in borderline tuberculoid leprosy (BT), while CD8⁺ lymphocytes predominated in the granuloma of lepromatous lepromatous (LL). The CD4⁺/CD8⁺ ratio and percentage of lymphocytes expressing IL-2R was significantly higher in BT as compared with LL. These immunophenotypic findings suggest that in both cutaneous tuberculosis and leprosy there is a continuous spectrum with regard to cell-mediated immunity depending on the clinical presentation.     

Characterization of CD45RO+ memory T lymphocytes in keloid disease

Keloid is a type of scar which seems like an overgrown scar, and can even be larger or more visible than the original wound. They are most common in darker skin types. Although the exact causes of keloid remain unknown, we know that the immune system is involved. Memory T lymphocytes are cells that can provide a rapid and highly effective immune response against pathogens (harmful bacteria or viruses) and can recognize a wide variety of antigens (toxins or foreign substances in the body). In this study, the authors sought to investigate the abnormalities of a specific memory T cell called CD3⁺CD45RO⁺ in keloid scars by analyzing blood and tissue samples. The authors, from Shanghai, China, found that most of T lymphocytes in keloid scars are CD3⁺CD45RO⁺ memory T cells, and they describe the ways in which this type differs from another type of memory T cells called FOXP3^‐CD8^‐mT. The authors also identified a profound decrease in the number of cells, called CD4⁺CD25^highFOXP3⁺ regulatory T cells, in patients with multiple keloid scars, and a significant increase of CD8⁺CD103⁺ memory T cells in keloid scars. The authors concluded that there exist distinct abnormalities in CD45RO⁺ memory T‐cell subsets in keloid scars and it may imply that dysregulation of T cell responses may play a role in the development of keloid scarring. Further research is required.     

Adhesion molecules and IL-1 costimulate T lymphocytes in the autologous MECLR in psoriasis

Membrane molecules such as CD36 (OKM5), intercellular adhesion molecule-1 (ICAM-1, CD54), gamma interferon-induced protein 10 (γ-IP10) and IL-1 are induced and/or upregulated in psoriatic epidermis. These molecules have important accessory, trafficking or signalling functions in the immune system and also play a role in the pathophysiology of psoriasis. The relevance of adhesion molecules, CD36 and epidermal IL-1 in psoriasis was studied in vitro in the autologous mixed epidermal cell-T lymphocyte reaction (MECLR). Their level of expression was quantitated in epidermal cell suspensions (ECS) from patients with psoriasis and their function was assessed by blocking with specific mAbs and antisera or by depleting CD36⁺ cells from the ECS prior to the MECLR. ECS from psoriatic lesions contained increased numbers of CD36⁺ (23±12%), ICAM-1⁺ (31±14%) and IL-1⁺ (57±21%) cells. The autologous MECLR was inhibited in saaples from all patients by mAb to CD2 (LFA-2), CD11a (LFA-1α), CD18 (LFA-1β), ICAM-1, CD58 (LFA-3) and an antiserum to IL-1β. Thus, adhesion molecules facilitate inflammation in psoriasis not only via adhesion and recruitment of T lymphocyte in psoriatic lesions, but also via activation of T cells. Furthermore CD36 molecules on psoriatic epidermal cells do not costimulate autologous T lymphocytes in psoriasis. The observed costimulatory function of IL-1β in the MECLR emphasizes its relevance in psoriasis.     

Th17细胞、IL-17A mRNA及IL-23R mRNA与寻常性银屑病的关系

目的 探讨寻常性银屑病（PV）皮损中IL-17A mRNA及IL-23R mRNA水平、外周血CD4+IL-17+ T细胞数量及它们与疾病严重程度的关系。方法 PV组25例,对照组14例。对PV皮损面积和严重指数（PASI）评分,用RT-PCR检测皮肤中IL-17A mRNA及IL-23R mRNA的水平,并用流式细胞仪测定20例PV患者及10例对照组外周血CD4+IL-17+ T细胞的数量。结果 PV组IL-17A mRNA的水平明显高于对照组（0.996 ± 0.231比0.437 ± 0.096,t = 10.57,P < 0.05）,IL-23R mRNA水平也明显高于对照组（1.006 ± 0.339比0.491 ± 0.196,t = 6.02,P < 0.05）。PV皮损中IL-17A mRNA与IL-23R mRNA的水平与PASI均呈线性正相关（分别为r s ＝ 0.67,P < 0.05;r s ＝ 0.70,P < 0.05）。外周血CD4+IL-17+ T细胞数量在两组差异无统计学意义。PV组中,外周血中CD4+IL-17+ T细胞数量与皮损中IL-17A mRNA、IL-23R mRNA水平无相关性。结论 PV皮损中IL-17A mRNA及IL-23R mRNA 的水平升高,与疾病严重程度相关,外周血Th17细胞数量无改变。     

Melkersson Rosenthal syndrome: a histopathologic mystery and dermatologic challenge

Melkersson Rosenthal syndrome (MRS) is rare disease of unknown etiology characterized by orofacial edema, facial nerve palsy and fissured tongue. Microscopically, it shows epithelioid non‐caseous granulomas; however, edema and perivascular lymphocytic infiltrates have been described. Two different clinical forms of MRS are presented in this report. In the complete form (Case 1), the main histopathologic finding was a non‐necrotizing granulomatous inflammation with 56% of the total number of cells composed of B cells (CD 20⁺) principally located in the granuloma's center and 33% being T cells predominating in the surrounding area, of which 48% were CD 4⁺ and 16% were CD 8⁺ lymphocytes. In the monosymptomatic form (Case 2), the inflammatory cells were dispersed into the connective tissue without granulomatous formation. B cells were scanty, and 78% of the cells were CD 45⁺ T cells, with 46% and 34%, CD 8⁺ and CD 4⁺ phenotype, respectively. These cases showed different clinical, histopathological and immunohistochemical forms of MRS, suggesting different host immune responses. Kaminagakura E, Jorge J Jr. Melkersson Rosenthal syndrome: a histopathologic mystery and dermatologic challenge.     

Augmented telomerase activity and reduced telomere length in parthenium‐induced contact dermatitis

Background Parthenium dermatitis is a common chronic inflammatory disease with activated T lymphocytes that recognize the antigens, which leads to proliferation and differentiation. Telomeres and telomerase play an important role in the regulation of life span of the cell. Telomere length maintained by telomerase, are specialized repeats present at the end of chromosomes which protect it from degradation, end‐to‐end fusion and are important for integrity of chromosomes. Objectives The aim of this study was to measure telomerase activity and telomere length in Peripheral blood mononuclear cell (PBMC), CD4⁺ and CD8⁺ T lymphocytes from parthenium dermatitis patients. Methods The study includes 50 patients of parthenium dermatitis confirmed by patch testing and 50 healthy controls. Telomerase activity was measured using the telomere repeat amplification protocol using PCR–ELISA kit. Telomere length was measured by using Telo TAGGG Telomere Length Assay Kit. Results Significantly elevated levels of telomerase activity was observed in PBMC, CD4⁺ and CD8⁺ T cells of parthenium dermatitis patients as compared with healthy controls. However, significantly reduced telomere length in PBMC, CD4⁺ and CD8⁺ T cells have been found in patients than healthy subjects, but there was no difference between CD4⁺ and CD8⁺ T cells in patients. Conclusion This study might have provided insight into the role of telomerase in parthenium dermatitis that is characterized by the recruitment of T lymphocytes, which play an important role in this inflammatory disease. The augmented telomerase activity and reduced terminal restriction fragment length might be explored as a potential diagnostic/prognostic marker for parthenium dermatitis in future.     

CD8+ cytolytic T lymphocytes and the skin

Abstract: T lymphocytes show a special affinity for the skin. Although the roles played by the CD4⁺ population of T lymphocytes in immunodermatology were so far actively investigated, much less is known about the roles played in the skin by CD8⁺ cytolytic T lymphocytes (CTL). The activity of CD8⁺ CTL in the immunodermatological context, however, is likely to be most important; the immuno-biology itself of CD8⁺ CTL, moreover, although far from being fully understood, shows intriguing characteristics. Immunophenotype, function and cytokine profile of CD8⁺ CTL are overviewed in the first section of this review. Phenotypically, not only CD8⁺ CTL can be subdivided into CD8⁺ CD28⁺ CD11b⁺ and CD8⁺ CD28^- CD11b⁺ subsets, but also an up-to-now undetected CD8⁺ CD28^- CD11b^- subset does exist. Functionally, not only “cytotoxic” but even “suppressor” subpopulations have been shown to exert cytolytic capabilities indeed, and “suppression” itself may be due to such a lytic capacity. According to cytokine synthesis, CD8⁺ CTL can be split into Tc1 and Tc2 subsets, each able to influence specific patterns of immune responses. The impact of CD8⁺ CTL in immunodermatology, overviewed in the second section of the current review, is crucial. The pathophysiology of inflammatory dermatoses is deeply influenced by the activity of CD8⁺ CTL: e.g., CD8⁺ CTL within psoriateic epidermis are possibly associated to the persistence of psoriatic lesions not undergoing resolution; on the other hand, in late lesions of lichen planus CD8⁺ CTL predominate, thus explaining presumably both the cytolytic attack against keratinocytes and the modulation of the inflammatory reaction up to the final resolution of the lesions; Tc1 cells are decreased in atopic dermatitis, and such a decrease can account both for IgE overproduction and for development of infections. Finally, CD8⁺ CTL can sustain against cutaneous viruses/tumors cytolytic immune responses not only of secondary but even of primary type, i.e. induced by Langerhans cells/dendritic cells either transfected or pulsed with skin virus/tumor-associated antigens, thus allowing the production of vaccines against cutaneous viral/neoplastic diseases.     

Characterization of the T cell response in allergic contact dermatitis caused by corticosteroids

Background Delayed allergic hypersensitivity reactions have classically been described as type IV reactions, which are caused by T cells; however, the respective roles of CD4⁺ and CD8⁺ cells are yet to be defined. A central role for CD8⁺ cytotoxic T cells as effector cells has been suggested. Objectives To determine the type of T cell involved in corticosteroid allergy. Methods We analysed the kinetics of T cell recruitment and the cytokine production profile in positive patch tests of 27 corticosteroid‐sensitized patients, as compared with control sites and control subjects. Skin biopsies, collected at 8, 24 and 48 hr following drug application, were embedded in paraffin for histological and immunohistological staining, and, in some cases, also deep‐frozen for gene expression analyses. Results CD3⁺ T cells were rapidly recruited in concert with the positivity of the patch test sites. High levels of interleukin (IL)‐4, IL‐5 and, to a lesser extent, interferon‐γ suggested that both Th2 and Th1 cytokines were implicated. IL‐4 was also produced by γδ T cell receptor (TCR) lymphocytes. Conclusions This study showed that, in allergic contact dermatitis caused by corticosteroids, the inflammatory infiltrate is composed of CD3⁺ T cells with a predominant Th2 cytokine profile, among which IL‐4 is also produced by γδ TCR lymphocytes.     

Possible role of superantigens in inducing autoimmunity in pemphigus patients

The diagnostic and pathological relevance of anti‐desmoglein autoantibodies in common forms of pemphigus has been well established, and T cells have been shown to play a role in the onset and progression of these diseases. The role of superantigens in provoking polyclonal activation of T cells with many different fine specificities, possibly including autoreactive T cells and T‐cell mediated autoantibody response, is unknown. Further, abnormal T‐cell function may lead to opportunistic infections particularly with Candida. The response of T cells of pemphigus patients to recall antigens of these opportunists is not clear. The aim of this study was to investigate the in vitro response of T lymphocytes from pemphigus patients to common bacterial superantigens such as streptococcal pyrogenic exotoxin A and staphylococcal enterotoxin B, and recall antigens such as Candida antigen. Changes in CD3⁺CD4⁺ and CD3⁺CD8⁺ T‐cell sub‐populations and expression of naive/memory markers (CD45RA⁺/RO⁺) on different T cells were analyzed by flow cytometry. Significant elevation in CD3⁺CD4⁺ and expression of the memory (CD45RO⁺) markers on these cells was observed both in pemphigus vulgaris and pemphigus foliaceus patients, as compared to healthy controls, upon stimulation with streptococcal pyrogenic exotoxin A and staphylococcal enterotoxin B. However, only memory T cells (CD45RO⁺) were significantly increased upon Candida antigen stimulation. Our study suggests that CD4⁺ memory T lymphocytes may modulate the pathogenic autoantibody response in pemphigus patients, and also emphasizes the possibility that the superantigen‐reactive T cells participate in the triggering of autoimmunity in pemphigus.     

Reduction of skin-homing cytotoxic T cells (CD8+ -CLA+) in patients with vitiligo

Background: Vitiligo is a frequently acquired, hereditary disease, characterized by achromic macules due to the absence of melanocytes. In contrast with earlier studies, in which the main pathogenic role was attributed to anti‐melanocyte antibodies, recent papers have emphasized a role for CD8⁺ cytotoxic T lymphocytes in melanocyte destruction. Fifteen percent of peripheral T cell express cutaneous lymphocyte‐associated antigen (CLA), responsible for skin‐homing T cell. Phototherapy is used to treat patients with generalized vitiligo and it has been shown to interfere with CLA⁺ T cells in other skin diseases. Objective: To describe peripheral blood T cell subpopulations' frequency and ability to express the skin‐homing molecule (CLA) in patients with non‐segmental vitiligo, before and after photochemotherapy (PUVA). Patients and Methods: Twenty‐two patients with generalized and active spreading vitiligo were submitted to 30 PUVA‐8MOP sessions. Lymphocyte immunophenotyping was performed by flow cytometry using anti‐CD3, anti‐CD8 and anti‐CLA monoclonal antibodies. Fifteen healthy volunteers, sex‐ and age‐matched, were included as a control group. Results: CD8⁺–CLA⁺ T cells were significantly reduced in number in untreated vitiligo patients (P=0.008) when compared with control individuals, albeit with a more intense CLA expression (P=0.028). These findings were not altered after PUVA. No significant difference was noticed in CD4/CD8 ratios nor in CD4–CLA⁺ T cell numbers between vitiligo patients and controls, both before and after PUVA. Conclusions: CD8–CLA⁺ T cells are reduced in peripheral blood of patients with non‐segmental vitiligo. This finding may be related to the previously reported increase of CD8⁺ cells in both lesions and perilesional skin of these patients.     

Density and proportions of the epidermal T cell population in human sun-exposed skin differ from those in sun-protected skin: preliminary immunohistochemical study

Epidermal T cells, which are found in clinically normal human skin, show topographic differences in density and proportions; however, the mechanisms and the biological consequences of such differences are still unknown. In a previous work, we showed that epidermal T cells are altered in number and composition after a single exposure to solar-simulated radiation (SSR). The purposes of the present investigation were, first, to compare the density of epidermal T cells and the proportion of T cell subpopulations in habitually sun-exposed versus sun-protected sites; second, to determine the effects of repetitive exposures to SSR on the latter cell populations. Biopsies from habitually sun-exposed, sun-protected and solar-simulated-exposed skin of 28 healthy volunteers were taken and immunohistochemistry was performed on cryostat sections. Compared with sun-protected sites, epidermal CD3⁺ T cell numbers of habitually sun-exposed sites were significantly lower. Double staining showed that the number of CD3⁺CD8⁺ T cells was significantly lower in sun-exposed than in sun-protected skin, whereas the numbers of CD3⁺CD4⁺ T cells were similar in both sites. Therefore, the CD4/CD8 ratio was markedly higher in sun-exposed compared to sun-protected sites. Moreover, repeated exposures of sun-protected skin to SSR induced a significant reduction in number of epidermal CD3⁺ T cells. The mean number of epidermal CD3⁺CD8⁺ double stained cells significantly decreased after such exposures, while the epidermal CD3⁺CD4⁺ T cell subpopulation was not significantly changed. In conclusion, both chronically sun-exposed skin and repeatedly SSR-exposed skin show a decrease in density of epidermal CD3⁺ and CD3⁺CD8⁺ T cells. We hypothesize that such sun-induced changes may weaken the immunosurveillance capacity of the skin and therefore increase the occurrence of skin cancer.     

A comparative immunohistochemical study of lichen planus and discoid lupus erythematosus

A comparative immunohistochemical study was performed on skin biopsies from 10 patients with lichen planus and 10 patients with discoid lupus erythematosus (DLE). A panel of antibodies against T lymphocytes (UCHL-1, OPD-4, CD8, CD45), B lymphocytes (L-26), granulocytes (Leu-M1), activation markers (Ki-1, LN-3), macrophages, fibroblasts and dendritic cells (FXIIIa, S-100, Mac-387, K.P-1, vimentin), endothelial cells (CD34), and epithelial cells (epithelial membrane antigen) was employed using a peroxidase-anti-peroxidase technique. The recently released CD8 antiserum required microwave antigen retrieval of formalin-fixed, paraffin-embedded tissue to label lymphocytes. The results showed many similarities in the lymphocyte subsets and macrophages between lichen planus and discoid lupus erythematosus. The most important differences between the two conditions were statistically significant increases in the number of S-100⁺ cells in the epidermis and dermis, FXIIIa⁺ cells in the dermis and CD34⁺ vessels within the inflammatory infiltrate in lichen planus.     

CD8+ dermal T cells from a sulphamethoxazole-induced bullous exanthem proliferate in response to drug-modified liver microsomes

There is evidence that T lymphocytes play a critical role in the pathogenesis of drug-induced bullous exanthems. Sulphonamides are known to be among the most frequent aetiological agents in these severe drug-induced cutaneous hypersensitivity reactions. Several studies indicate that cytochrome P450-dependent metabolites of sulphonamides act as the nominal allergens. A 70-year-old woman with a severe blistering exanthem caused by cotrimoxazole (sulphamethoxazole and trimethoprim) was studied. We employed an in vitro approach to determine whether cytochrome P450-dependent enzymes activated drug-specific T lymphocytes from this patient. Immunohistochemical analysis of involved skin revealed a majority of epidermal CD8⁺ T lymphocytes, whereas the dermal infiltrate was composed of both CD4⁺ and CD8⁺ T cells. Dermal T lymphocytes isolated from lesional skin proliferated in response to sulphamethoxazole, but not to trimethoprim, in the presence of autologous mononuclear cells used as antigen-presenting cells. The antigen-specific response of sulphamethoxazole-specific T cells was significantly augmented in the presence of murine liver microsomes with P450-dependent catalytic activities. Our observations suggest that some cutaneous hypersensitivity reactions to sulphamethoxazole are due to drug-specific T lymphocytes. Cytochrome P450-dependent enzymes may play a critical role in the formation of the nominal antigen, which is recognized by antigen-specific T cells.     

Evidence that regression in Keratoacanthoma is immunologically mediated: a comparison with squamous cell carcinoma

Recent research observations suggest that the keratoacanthoma (KA) is a form of resolving squamous cell carcinoma (SCC). The mechanism by which this resolution takes place has not been fully explored, although it may have an immunological basis. To investigate this, we compared 15 clinically and histologically diagnosed KAs and 15 SCCs with regard to cellular infiltrate and keratin expression. We found that KAs have significantly higher numbers of CD3⁺ and CD4⁺ cells invading their epidermal component than SCCs. The lymphocytes infiltrating KAs were more immunologically active, as greater numbers expressed the interleukin-2 receptor (IL-2R) than those in SCCs. It is of interest that CD36 was expressed by a significantly greater proportion of tumour cells within KAs than SCCs. This was also the case for the intercellular adhesion molecule ICAM-1, and the differentiation marker keratin 10. Overall, these findings suggest that KA regression is immunologically mediated, with activated (IL-2R⁺) CD4⁺ T lymphocytes and adhesion molecules playing a pivotal role in the immune response.     

In situ depletion of CD4<Superscript>+</Superscript> T cells in human skin by Zanolimumab

CD4⁺ T cells, in activated or malignant form, are involved in a number of diseases including inflammatory skin diseases such as psoriasis, and T cell lymphomas such as the majority of cutaneous T cell lymphomas (CTCL). Targeting CD4 with an antibody that inhibits and/or eliminates disease-driving T cells in situ may therefore be a useful approach in the treatment of inflammatory and malignant skin diseases. Depletion of CD4⁺ T cells in intact inflamed human skin tissue by Zanolimumab, a fully human therapeutic monoclonal antibody (IgG1, κ) against CD4, was studied in a human psoriasis xenograft mouse model. Zanolimumab treatment was shown to induce a significant reduction in the numbers of inflammatory mononuclear cells in upper dermis. This reduction in inflammatory mononuclear cells in situ was primarily due to a significant reduction in the numbers of skin-infiltrating CD4⁺, but not CD8⁺ CD3⁺ T cells. The capacity of Zanolimumab to deplete the CD4⁺ T cells in the skin may be of importance in diseases where CD4⁺ T cells play a central role. Indeed, in a phase II clinical trial Zanolimumab has shown a dose-dependent clinical response in patients with CTCL and the antibody is currently in a phase III clinical trial for CTCL, a disease for which there is no safe and effective treatment available today.