FS02.2CD4+ CCR10+ effector T cells reside at former allergic contact dermatitis sites

Local skin memory (LSM) describes the clinical phenomenon of an accelerated and increased inflammatory allergic contact dermatitis (ACD) response upon renewed allergen exposure. This has been ascribed to the local persistence of few, but allergen‐specific, T cells. Here, firstly, we characterized effector T cells, and, subsequently, studied which of these cell populations are present at former challenge sites and might contribute to LSM. Peripheral blood T cells were stimulated with nickel sulphate. Cellular phenotypes and chemokine receptor expression profiles were analysed by FACS‐staining: CLA together with CD4/CD8, CD45R0/RA, CXCR3, CCR4, CCR6 and CCR10. Skin biopsies were taken at 0, 3 and 21 days after allergen application and analysed for the same markers. Upon nickel‐stimulation, amount of CD4+ CLA+ CD45R0+ T cells was increased. Together with CLA, CXCR3, CCR4 and, mainly, CCR10 expression was augmented. CCR6 expression was negative on CLA+ cells. In biopsies from patch tests, cellular infiltrates were present at 3 and 21 days after allergen application. Interestingly at day 21, residing cells were localized at the perivascularity and were characterized as CD4+ CD8− CCR10+ T cells. In conclusion, nickel‐activated effector T cells can be characterised as CD4+ CD8− CLA+ memory T cells. They express CXCR3, CCR4 and, in particular, CCR10. After clinical recovery from an ACD reaction, CD4+ CCR10+ memory T cells apparently reside locally. The persistence of these CCR10+ T cells, expressing the appropriate receptor of the skin specific chemokine CCL27, can explain clinically important phenomena such as LSM and flare up reactions.     

Circulating clonal CLA(+) and CD4(+) T cells in Sezary syndrome express the skin-homing chemokine receptors CCR4 and CCR10 as well as the lymph node-homing chemokine receptor CCR7

BACKGROUND: Adhesion molecules and chemokine receptors are involved in tissue-specific homing of T cells to the skin and play an important role in the pathophysiology of cutaneous lymphoma. It has recently been reported that the chemokine CCL27 expressed by keratinocytes attracts lymphocytes bearing the chemokine receptor CCR10. OBJECTIVES: To investigate the expression of CCR4, CCR7 and CCR10 on skin-homing CLA(+) and CD4(+) T cells in the peripheral blood of patients with Sezary syndrome (SS), a rare leukaemic variant of cutaneous T-cell lymphoma. METHODS: Lymphocytes from five patients with SS, six patients with mycosis fungoides and four healthy volunteers were isolated and analysed using flow cytometry. Additionally, the T-cell receptor (TCR)-Vbeta CDR3 regions were cloned and sequenced in two patients. RESULTS: We found that CCR4 is expressed on almost all CLA(+) and CD4(+) memory T cells. Using monoclonal antibodies specific for single TCR-Vbeta chains we identified malignant T cells in four patients with SS. Importantly, we found that most but not all malignant Sezary cells expressed the skin-homing chemokine receptor CCR10. Additionally, we found that a significant proportion of these cells also expressed the lymph node-homing chemokine receptor CCR7. CONCLUSIONS: Our results support the concept that chemokine receptors play an important role in the pathophysiology of SS and suggest that the malignant clone may represent an expansion of skin-homing cutaneous 'central' memory T cells in the peripheral blood of these patients.     

Homing receptor and chemokine receptor on intraepidermal T cells in psoriasis vulgaris

Intraepidermal T lymphocytes found in psoriatic skin lesions are involved in the development and maintenance of lesional pathology. It has become clear that differential expression of homing and chemokine receptors determines the specific migration of T cells to distinct tissues and microenvironments, including psoriasis lesions. The aim of the present study was to clarify expression of homing (CLA, VLA-4, and LFA-1) and chemokine (CCR4, CCR6, CCR7, and CXCR3) receptors on intraepidermal T cells in psoriatic lesions using flow cytometry. The vast majority of intraepidermal T cells in psoriatic lesions expressed CLA and LFA-1, whereas 58% of CD4+ and 85% of CD8+ T cells expressed VLA-4. The majority of CD4+ T cells and about half of the CD8+ T cells expressed CCR4 and CCR6, whereas less than one-third of CD4+ and CD8+ T cells expressed CXCR3 or CCR7. In patients with psoriasis the percentages of T cells expressing CLA, CCR4, and CCR6 were much higher in the epidermis of psoriatic plaques than in the peripheral blood. Thus, CLA, CCR4, and CCR6 may play a more important role in the migration of T cells to psoriatic epidermis.     

Identification of lesional CD4+ CD25+ Foxp3+ regulatory T cells in Psoriasis

BACKGROUND: Depletion of CD4+ CD25+ Foxp3+ naturally occurring regulatory T cells (T(reg)) induces autoimmune phenomena. These cells have not yet been fully characterized in the skin of psoriatic patients. OBJECTIVES: To prove that the Zenon immunofluorescent labeling technique is suitable for the demonstration of co-localization of T-cell markers and in particular to show the distribution of T(reg) in psoriatic skin. METHODS: In biopsies derived from normal and psoriatic skin, CD4+ CD25+, CD4+ CD45RO+, CD8+ CD25+, CD8+ CD45RO+ and CD4+ CD25+ Foxp3+ cells in the dermis and in the epidermis were immunophenotyped, using a quantitative immunofluorescent labeling technique (Zenon), analyzed and compared using image analysis. RESULTS: The immunofluorescent labeling technique was shown to be an easy and reliable tool to demonstrate co-localization of T-cell markers. In psoriasis, all pathogenic T-cell subsets (CD4+ CD25+, CD4+ CD45RO+, CD8+ CD25+ and CD8+ CD45RO+ cells) were significantly increased in the dermis and in the epidermis, as compared to normal skin (all p < 0.05). Using this labeling technique we were able to reveal CD4+ CD25+ Foxp3+ T(reg) in psoriatic dermis, but not in the dermis of normal skin (p < 0.0001). CONCLUSIONS: The Zenon immunofluorescence technique in combination with image analysis is suitable for the demonstration of co-localization of T-cell markers in tissue. Increased numbers of pathogenic T cells (CD4+ CD25+, CD4+ CD45RO+, CD8+ CD25+ and CD8+ CD45RO+) were shown in the dermis and epidermis, whereas CD4+ CD25+ Foxp3+ T(reg) were identified in psoriatic skin with a predilection for the upper dermis.     

特应性皮炎患者外周血皮肤归巢的CD8+ T细胞研究

【摘要】 目的 探讨特应性皮炎（AD）患者外周血CD8+ T细胞皮肤归巢及杀伤功能相关蛋白的表达。 方法 15例AD患者和14例健康人,用流式细胞仪,检测外周血CD8+ T细胞、表达皮肤淋巴细胞相关抗原的CD8+ T细胞（CLA+CD8+ T细胞）的比例。 结果 CD8+ T细胞比例在AD组和对照组之间差异无统计学意义（P > 0.05）;CD8+ T细胞穿孔素、颗粒酶B和FasL的表达在两组间差异亦无统计学意义（均P > 0.05）。CLA+CD8+ T细胞比例在AD组（3.80% ± 1.46%）高于健康对照组（2.18% ± 0.85%）（t = 3.636,P < 0.01）,AD组CLA+CD8+ T细胞比例与SCORAD（SCORing of Atopic Dermatitis）评分呈正相关（r = 0.565,P < 0.05）;CCR4在CD8+ T细胞表达在AD组（13.86% ± 4.42%）高于健康对照组（9.50% ± 2.14%）（t = 3.738,P < 0.01）,而CCR10和CXCR6的表达在两组间差异均无统计学意义（P > 0.05）。CLA+CD8+ T细胞穿孔素的表达在AD组（74.27% ± 15.94%）高于健康对照组（57.20% ± 14.64%）（t = 2.998,P < 0.01）,颗粒酶B的表达在AD组（70.90% ± 13.85%）也高于健康对照组（56.41% ± 11.00%）（t = 3.104,P < 0.01）,而FasL的表达在两组间差异无统计学意义（P > 0.05）。CLA+CD8+ T细胞CCR4、CCR10和CXCR6的表达在AD组与对照组间差异无统计学意义（均P > 0.05）。 结论 AD患者外周血CLA+CD8+ T细胞数量增加,杀伤功能相关蛋白穿孔素、颗粒酶B的表达增强,可能参与了AD的发病。     

Expression of chemokines and chemokine receptors in cutaneous CD30+ lymphoproliferative disorders

BACKGROUND: Little is known about the mechanisms involved in skin-specific homing in CD30+ cutaneous lymphoproliferative disorders (CLPD). Chemokine/chemokine receptor interactions have been implicated in the homing of lymphoma cells to various tissue sites. OBJECTIVES: To investigate tissue samples from patients with CD30+ CLPD for the expression of the chemokine receptors CXCR3, CCR4 and CCR3 and their ligands MIG, TARC and RANTES. METHODS: Tissue samples from patients with primary cutaneous anaplastic large cell lymphoma (PCALCL, n=12) and lymphomatoid papulosis (LyP, n=13) were studied by immunohistochemistry on paraffin-embedded sections. Immunohistochemical analysis was also performed for CD20 (for B cells), CD45RO and CD3 (for T cells), CD30 and ALK-1. A portion of each skin specimen was stored at -80 degrees C and later examined using monoclonal antibodies against CD2, CD3, CD4, CD5, CD8, CD15, CD19, CD20 and CD30. RESULTS: CD30+ atypical lymphoid cells were frequently seen in PCALCL, and to a variable degree in LyP. In both disorders there were scattered CD3+ and CD45RO+ atypical lymphoid cells, but CD2, CD5, CD15, CD19, CD20 and ALK-1 showed negative reactivity. In addition, CD4+, but not CD8+, atypical lymphoid cells were occasionally seen in both disorders. CCR3 was expressed by atypical lymphoid cells in 10 of 12 (83%) cases of PCALCL, but in only five of 13 (38%) cases of LyP. CXCR3 was expressed in 11 of 13 (85%) cases of LyP, but in only one of 12 (8%) cases of PCALCL. CCR4 was expressed in 11 of 12 (92%) cases of PCALCL, but in only two of 13 (15%) cases of LyP. RANTES was strongly expressed by lymphoma cells in PCALCL (11 of 12: 92%), but was weak or sporadic in LyP (seven of 13: 54%). TARC showed weak or sporadic reactivity in both LyP and PCALCL, and MIG did not show a distinctive expression pattern in either disorder. CONCLUSIONS: We speculate that CCR3 is associated with the autocrine function in PCALCL, as evidenced by CCR3 coexpression with its ligand RANTES. We also found that LyP cells expressed CXCR3, which might support their migration towards the CXCR3 ligand MIG, which is expressed in stromal cells of the skin.     

趋化性细胞因子受体CCR4和CXCR3在特应性皮炎患者外周血的表达

目的为研究特应性皮炎患者外周血趋化性细胞因子受体CCR4和CXCR3在特应性皮炎的发病过程中的作用。方法采用三色流式细胞仪测定20例特应性皮炎患者和30例健康对照者外周血趋化性细胞因子受体CCR4和CXCR3的表达水平。结果特应性皮炎患者外周血CCR4+CD4+T细胞的水平明显高于对照组(P<0.01);特应性皮炎患者外周血CCR4/CXCR3比率明显高于对照组P<0.01);特应性皮炎患者外周血CXCR3+CD4+T细胞的水平与对照组差异无统计学意义。结论趋化性细胞因子受体CCR4可能促进了Th2细胞从血液进入特应性皮炎患者炎症皮损。     

CC chemokine receptor 4 expression on peripheral blood CD4+ T cells reflects disease activity of atopic dermatitis

Recent studies indicate that Th1 and Th2 cells differ in their chemokine receptor expression and their responsiveness to various chemokines. Therefore, selective Th2 cell recruitment in Th2-predominant inflammatory diseases such as atopic dermatitis may be under the influence of some chemokines. It is reported that CC chemokine receptor (CCR) 4 is selectively expressed on Th2 cells whereas CXC chemokine receptor (CXCR) 3 is selectively expressed on Th1 cells. In this study we examined CCR4 and CXCR3 expression on peripheral blood CD4+ and CD8+ T cells obtained from adult atopic dermatitis subjects, and compared the results with those from patients with psoriasis vulgaris and healthy controls. CCR4 was preferentially expressed on CD4+ T cells from atopic dermatitis subjects and CXCR3 was preferentially expressed on CD4+ T cells from psoriasis vulgaris subjects. This CCR4 expression was prominent especially in severe atopic dermatitis subjects. CCR4 expression on CD4+ T cells in severe atopic dermatitis subjects decreased on improvement of disease activity. CD25 was preferentially expressed on CCR4+CD4+ T cells but not on CXCR3+CD4+ T cells in atopic dermatitis subjects. Cutaneous lymphocyte-associated antigen was also preferentially expressed on CCR4+CD4+ T cells but not on CXCR3+CD4+ T cells in atopic dermatitis subjects. CD4+ T cells in atopic dermatitis skin lesions were predominantly CCR4+ cells. Taken together, this study strongly indicates that CCR4+CD4+ T cells reflect disease activity and suggests that CCR4 expression is important for T cell infiltration into atopic dermatitis lesions. Thus, CCR4 may be a possible target for therapy of atopic dermatitis in the future.     

Paradoxical increase in skin inflammation in the absence of CCR4

The chemokine receptors are seven transmembrane, G-protein-coupled surface receptors that play key roles in the migration and localization of leukocytes to the skin during physiologic and inflammatory states. Their ligands, chemokines, are small secreted proteins that initiate leukocyte chemoattraction. Recent data indicate that known subsets of T helper (Th) cells express signature chemokine receptors (e.g., CXCR3, CCR3/4, and CCR6) that help to define individual subsets such as Th1, Th2, and Th17 cells, respectively, although there is some degree of overlap among these T-cell subsets. In this issue, Lehtim?ki et al. use an oxazolone-induced contact hypersensitivity (CHS) model to show that T cells (as well as neutrophils and eosinophils) from CCR4(-/-) mice accumulate just as (if not more) efficiently in inflamed skin as compared with the same population of leukocytes from wild-type (WT) mice. Although somewhat unexpected, their results can be explained if CCR4 attracts both proinflammatory and suppressive T cells into skin in addition to serving functions that are partially redundant with those of CCR10. Finally, we discuss other possible roles for CCR4 in the homing of T cells to skin.     

Efalizumab therapy for atopic dermatitis causes marked increases in circulating effector memory CD4+ T cells that express cutaneous lymphocyte antigen

Efalizumab is an mAb directed against CD11a, a molecule involved in T-cell activation and extravasation from blood into tissue. Ten patients with severe atopic dermatitis were treated with efalizumab for 84 days, and peripheral blood mononuclear cells were analyzed for expression of activation and adhesion markers. Efalizumab treatment led to decreases in CD11a mean fluorescence intensity (MFI) on naive, central memory, and effector memory CD4+ and CD8+ T cell subsets. MFI for CD18 was decreased in both CD4+ and CD8+ T cells. Percentages of cells positive for cutaneous lymphocyte antigen (CLA) were increased fourfold in all CD4+ and CD8+ T cell subsets. Increases in the percentages of CD4+ and CD8+ T cells expressing beta7 and CD49d were also observed. No significant changes were observed in the percentages of CD4+ and CD8+ T cells that produced either IFN-gamma or IL-4. In summary, efalizumab treatment resulted in (i) decreases in CD11a and CD18 expression in all circulating T-cell subsets and (ii) increases in the percentages of blood T cells expressing tissue homing markers (CLA, beta7, CD49d). These data suggest that blockade of T-cell extravasation into tissue is the major pathway by which efalizumab leads to improvement in cutaneous inflammation.     

外周血流式细胞仪分析在淋巴瘤性红皮病诊断中的作用研究

【摘要】 目的 探讨外周血流式细胞仪检测在红皮病诊断中的应用价值。方法 收集2017年9月至2020年12月在中国医学科学院皮肤病医院就诊的29例红皮病患者,包括6例红皮病型蕈样肉芽肿（EMF）、5例Sézary综合征（SS）及18例不同病因的炎症性红皮病（IE）,4例健康志愿者为健康对照。采用流式细胞仪检测外周血淋巴细胞亚群、免疫表型及克隆性,比较其在炎症性红皮病与淋巴瘤相关红皮病的差异。采用单因素方差分析及LSD-t检验进行组间比较。结果 4组受试者的T细胞、B细胞、NK细胞及CD4-CD8-细胞比例差异均有统计学意义（均P < 0.001）,SS患者T细胞比例（93.8% ± 3.4%）高于EMF（42.7% ± 6.4%）及IE（46.0% ± 6.8%,t = 12.8、14.4, P < 0.001）,IE患者CD4-CD8-细胞比例（0.37% ± 0.40%）低于EMF（2.93% ± 0.84%）及SS（2.38% ± 0.74%,t = 9.2、6.7, P < 0.05）。健康对照及IE患者均未检测到克隆性T细胞受体可变区β链（TCR-vβ）表达;3例 EMF及所有SS患者检测到表达克隆性TCR-vβ的细胞亚群,且TCR-vβ克隆性细胞均为CD4+CD7-CD26-表型。4组受试者CD4+ T淋巴细胞表面表达趋化因子受体CCR4、CXCR3、CCR5与皮肤淋巴细胞抗原（CLA）及程序性死亡受体1（PD-1）的细胞比例差异均有统计学意义（均P < 0.001）,IE患者表达CCR4、CLA、PD-1细胞比例低于SS及EMF患者（均P < 0.001）,表达CXCR3、CCR5细胞比例高于SS患者及EMF患者 （均P < 0.001）。 结论 流式细胞仪检测外周血淋巴细胞亚群、免疫表型及克隆性,可为红皮病患者的病因诊断提供佐证,有助于淋巴瘤相关红皮病与炎症性红皮病的鉴别诊断。     

Characterization of lymphocyte subpopulations and cytokine profiles in peripheral blood of nickel-sensitive individuals with systemic contact dermatitis after oral nickel exposure

Several studies have shown that oral nickel exposure can elicit systemic contact dermatitis (SCD) in nickel-sensitive individuals. The current study describes some of the immunological mechanisms underlying such nickel-allergic reactions elicited by oral exposure to nickel. Following oral exposure to graded concentrations of nickel or placebo, blood samples were taken from nickel-sensitive individuals and from non-nickel-sensitive controls. T-cell subtypes (CD3+, CD4+, CD8+ and CD45RO+), expression of skin-homing receptor, cutaneous lymphocyte-associated antigen (CLA) and cytokine profiles [interleukin (IL)-2, IL-4, IL-5, IL-6, IL-10, interferon-gamma and tumour necrosis factor-alpha] were investigated. A definite dose-response reaction pattern to oral nickel exposure was observed among nickel-sensitive individuals. Nickel-sensitive individuals whose dermatitis flared after oral challenge with nickel showed significant decreases in fractions of CD3+ CD45RO+ CLA+ and CD8+ CD45RO+ CLA+ blood lymphocytes, suggesting migration of CD8+ 'memory' CLA+ T lymphocytes from the blood to peripheral tissues. Only those nickel-sensitive individuals who clinically reacted to oral challenge with nickel (4 mg) had elevated levels of IL-5 in the serum, indicating an activation of type 2 T lymphocytes in the peripheral blood. In conclusion, the study indicates that CD8+ CD45RO+ CLA+ T lymphocytes and T lymphocytes with a type 2 cytokine profile are involved in SCD elicited by nickel.     

Memory effector (CD45RO+) and cytotoxic (CD8+) T cells appear early in the margin zone of spreading psoriatic lesions in contrast to cells expressing natural killer receptors, which appear late

BACKGROUND: An influx of immunocytes, increased epidermal proliferation and abnormal keratinization are hallmarks of the psoriatic lesion. T-lymphocyte subsets in particular activated effector memory T cells and natural killer (NK) T cells have been suggested to play an important role in the pathogenesis of psoriasis. OBJECTIVES: In the present study we investigated the number of T-cell subsets (CD4, CD8, CD45RO, CD45RA, CD2, CD25), cells expressing NK receptors (CD94 and CD161), the proliferation marker Ki67 and the keratinization marker keratin (K10) across the margin of the spreading psoriatic plaque: distant uninvolved skin, the outer margin (immediately outside the clinical edge), the inner margin (immediately inside the clinical edge) and the central area. PATIENTS AND METHODS: Eight patients with active psoriasis vulgaris participated in this study. Biopsies were taken from the spreading psoriatic lesion from the distant uninvolved skin, the outer margin, the inner margin and the central area. Biopsies were processed for immunohistochemical staining. RESULTS: In the outer margin CD8+ (cytotoxic T cells) and CD45RO+ (memory effector T cells) T lymphocytes invade the epidermis and in this early stage the activation markers CD2 and CD25 also show a substantial increase. The next phase, from the outer to the inner margin, shows a statistically significant increase of these markers, and especially, the cells expressing NK receptors (CD94 and CD161) show a massive increase together with a significant increase of epidermal proliferation (Ki67) and a decrease of the K10+ epidermal surface. CONCLUSIONS: CD8+, CD45RO+, CD2+ and CD25+ T cells have a role in the early phase of the psoriatic process, whereas CD94- and CD161-expressing cells together with epidermal proliferation and keratinization are involved in a later phase.     

镍接触性皮炎皮损趋化因子及其受体的研究

目的 探讨趋化因子及其受体在镍接触性皮炎发病中的作用.方法 留取镍接触性皮炎患者直接接触部位皮损和部分患者非直接接触部位皮损进行趋化因子受体CXCR3和CCR4免疫组化染色,同时采用RT-PCR分析HaCaT细胞经硫酸镍刺激后γ干扰素诱导蛋白-10(IP-10)、干扰素诱导T细胞趋化因子α(I-TAC)、胸腺活化调节的趋化因子(TARC)和巨噬细胞来源趋化因子(MDC)在mRNA水平的表达情况.结果 镍接触性皮炎患者皮损中浸润细胞以CD45Ro⁺CD4⁺T细胞为主,CD8⁺细胞比例小于25%;直接接触与非直接接触部位皮损浸润细胞中50%以上CXCR3染色阳性,CCR4阳性细胞少于20%.HaCaT细胞经硫酸镍刺激后主要表达趋化因子IP-10和I-TAC,48～72 h最明显.结论 镍所致系统性接触性皮炎患者非直接与直接接触部位皮损在T细胞免疫反应的效应阶段炎症反应类型基本相同.     

High level of thymus and activation-regulated chemokine in blister fluid and sera of patients with bullous pemphigoid

BACKGROUND: Bullous pemphigoid (BP) is an autoimmune blistering disease characterized by eosinophilia and high serum IgE levels. The accumulated evidence suggests that various cytokines are involved in the lesional skin of patients with BP. Recently, thymus and activation-regulated chemokine (TARC/CCL17), a CC chemokine, was identified as a selective chemoattractant for CC chemokine receptor 4 (CCR4)-expressing cells. OBJECTIVE: In this study, we examined the involvement of TARC in patients with BP. METHODS: We determined the fluid and serum TARC levels in patients with BP by enzyme-linked immunosorbent assay and compared the serum TARC levels with the eosinophil numbers in peripheral blood. We also compared the serum TARC levels in five patients with BP before and after they were treated. Moreover, we examined TARC, CCR4 and CXC chemokine receptor 3 (CXCR3) expression in the lesional skin of patients with BP by immunohistochemical procedures. Furthermore, we measured CCR4 positivity in CD4+ CD45RO+ cells of peripheral blood mononuclear cells (PBMCs) in patients with BP and healthy control subjects. RESULTS: The fluid TARC levels in patients with BP were significantly higher than those in blisters from burn patients or suction blisters of healthy control subjects. The serum TARC levels in patients with BP were also significantly higher than those in pemphigus vulgaris (PV) patients and healthy control subjects, and decreased after the treatment. The serum TARC levels in patients with BP significantly correlated with the eosinophil numbers in peripheral blood (r = 0.72, P < 0.002). Immunohistochemistry showed a strong reactivity of TARC in the epidermal keratinocytes (KCs) of BP. Moreover, both CCR4 and CXCR3 were expressed on the dermal infiltrating CD4+ T cells mainly beneath the bullae of patients with BP. Fluorescence-activated cell sorting analysis showed a higher percentage of CCR4 positivity in CD4+ CD45RO+ cells of PBMCs in patients with BP than that in healthy control subjects, while there was no significant difference of CXCR3 positivity in CD4+ CD45RO+ cells of PBMCs between patients with BP and healthy control subjects. CONCLUSIONS: These findings strongly suggest that TARC may be one of the important chemokines that are involved in the pathogenesis of BP.     

Increased CCR4 expression in cutaneous T cell lymphoma

Chemokines are critical molecules in leukocyte trafficking, promoting site-specific migration to various tissues. The chemokine receptor CCR4 has recently been associated with skin-homing T cells. In view of the potential importance of CCR4 in skin homing of T cells, we investigated the expression pattern of CCR4 and its ligands TARC/CCL17 and MDC/CCL22 in the peripheral blood and skin of patients with cutaneous T cell lymphoma, a putative malignancy of the skin-homing T cells. In this study we analyzed the pattern of coexpression of the skin-homing molecules cutaneous lymphocyte antigen (CLA) and CCR4 in the blood and skin of patients with cutaneous T cell lymphoma. In the blood of cutaneous T cell lymphoma patients with peripheral blood involvement we found significantly increased percentages of T cells displaying the skin-homing phenotype (CLA+CCR4+) compared with healthy individuals. T cells expressing CLA and CCR4 were also found at high levels in cutaneous T cell lymphoma lesions along with abundant expression of the two CCR4 ligands TARC/CCL17 and MDC/CCL22. These data may explain, in part, why these T cells accumulate in the skin, a diagnostic feature of cutaneous T cell lymphomas.     

Selective persistence of dermal CD8+ T cells in lesional plaque psoriasis after clobetasol-17 propionate treatment

In psoriasis, T-cell infiltration and epidermal hyperproliferation are key phenomena which are closely related. Our aim was to investigate the dynamics among T-cell subsets in relation to epidermal proliferation and clinical severity in psoriasis during treatment with an ultra-potent corticosteroid. Seven psoriasis patients were treated twice daily for 14 days with clobetasol-17 propionate ointment. Punch biopsies were taken at day 0, 3, 7 and 14. Epidermal proliferation marker Ki-67 and CD4+, CD8+, CD45RO+, CD2+ T cells were quantified by immunohistochemical techniques and image analysis. The clinical score declined significantly (60%; p<0.01) and a 47% reduction of Ki-67+ nuclei was observed after only 3 days (p<0.01). In the epidermis all investigated T-cell subsets were significantly reduced at day 14 (p<0.05). In the dermis, treatment resulted in a significant decrease of CD4+, CD45RO+ and CD2+ T cells, but dermal CD8+ T cells persisted. In psoriasis, reduction of clinical severity and epidermal proliferation during the early phase of topical corticosteroid therapy cannot primarily be the result of decreased T-cell subsets. Furthermore, selective persistence of dermal CD8+ T cells was observed, which might be associated with disease relapse.     

CD4+ cutaneous T-cell lymphomas show the phenotype of helper/inducer T cells (CD45RA-, CDw29+)

CD4+ T cells are heterogenous and include at least two subsets that differ in their influence to immunoglobin synthesis, cytokine secretion pattern and immunophenotype. Among others these subsets have been designated as suppressor/inducer or naive T cells (CD45RA+, CDw29-) and helper/inducer or memory T cells (CD45RA-, CDw29+). Current theories suggest that these CD4+ T-cell subsets either reflect sequential stages of maturation before and after activation (antigen contact) or represent distinct lineages. In this study, we systematically analyzed the participation of both suppressor/inducer (CD45RA+) and helper/inducer (CDw29+) T cells in the dermal lymphohistiocytic infiltrate of various CD4+ cutaneous T-cell lymphomas. Although in peripheral blood both subsets are equally distributed, we present evidence that all CD4+ cutaneous T-cell lymphomas are of the helper/inducer T cell phenotype. These findings are of importance both for pathogenetic and clinical considerations: the presence of plasma cells in dermal infiltrates and the elevation of serum immunoglobulins in patients of mycosis fungoides may be the consequence of interleukin-4 secretion of the neoplastic CD4+ helper/inducer cells. The exclusive memory T cell phenotype of cutaneous T-cell lymphomas may be due to a general predominance of this subset in the skin, or be the consequence of cellular activation during malignant transformation.     

Decreased total numbers of peripheral blood lymphocytes with elevated percentages of CD4+CD45RO+ and CD4+CD25+ of T-helper cells in non-segmental vitiligo

Vitiligo is a disorder involving progressive skin depigmentation caused by host mediated destruction of melanocytes. Its pathogenesis is known to correlate with elevated levels of activated skin-infiltrating T lymphocytes and is presumed to be autoimmune in nature. In the present study, we characterize the immunophenotype of peripheral blood T cells from vitiligo patients, with the objective of developing an investigative and diagnostic tool for the disease, using analysis of peripheral blood. Subjects for this investigation included 32 patients diagnosed with non-segmental vitiligo and 28 age-and gender-matched, normal, healthy control participants. Whole venous blood taken from each subject was analyzed using 2-color flow cytometry for immunologically-relevant lymphocyte subsets. When compared with healthy control subjects, peripheral blood from individuals with vitiligo was found to have lower total numbers of lymphocytes (p<0.039). Vitiligo patients also had elevated percentages of memory (CD4+CD45RO+) T cells; (p<0.05), but NK-T cells (CD3+CD16+CD56+) and naive T cells (CD4+CD45RA+) were present at lower total numbers and percentages than in healthy controls (p<0.01 and 0.05 respectively). Blood from severely afflicted subjects exhibited elevated CD3+HLADR+ and CD4+CD45RO+ as well as lower percentages of NK-T cells (p<0.05) when compared with mild cases. In conclusion, disease-associated, peripheral blood lymphocyte immunophenotypic profiles of vitiligo patients are consistent with the hypothesis of T cell activation as a major feature of the disorder. These include elevated memory and reduced naive T cell percentages and increased expression of the activation-associated surface antigen CD25. These changes presumably reflect increased antigen-mediated activation. Moreover, because a corollary effect is increased activation-induced cell death (AICD), lower overall lymphocyte counts observed in vitiligo-afflicted subjects is also expected.     

T cell receptor transfection shows non-HLA-restricted recognition of nickel by CD8+ human T cells to be mediated by alphabeta T cell receptors

CD8+ T cells have been assigned a prominent role in allergic contact dermatitis, including nickel allergy; however, human nickel-reactive T cells of the CD8+ phenotype have largely escaped detailed investigation. Here we characterize two quite unusual nickel-specific cytotoxic T cell clones isolated from the peripheral blood of two nickel-sensitized patients. These clones mediate nickel-specific cytolysis of many human cell lines, independent of the expression of HLA class I, CD1, or HLA class II molecules. Lysis is mediated by the alphabeta T cell receptors and involves the perforin, but not the Fas/Fas ligand pathway. Both antigen receptors lack sequence homology to each other as well as to typical natural killer T cell receptors. A transfectant expressing the rearranged alphabeta T cell receptor derived from one of the T cell clones unequivocally demonstrates that the T cell receptor itself is necessary and sufficient to confer HLA-independent nickel specificity. The independent isolation of these clones from two individuals points to an important role of such cells in the pathology of nickel contact dermatitis.