Up-regulation of the chemokine CCL18 by macrophages is a potential immunomodulatory pathway in cutaneous T-cell lymphoma

Mycosis fungoides (MF) is the most frequent form of cutaneous T-cell lymphoma (CTCL), which can deteriorate from patch stage to dermal-based tumors and systemic involvement in years. The interaction of chemokines in the skin with CTCL cells might have implications for the pathogenesis of the disease. In this study, we show by PCR analysis and immunofluorescence staining that the chemokine CCL18 is present in skin biopsy specimens of patients with MF and its precursor form parapsoriasis en plaque but not in healthy tissue. In addition, the serum levels of CCL18 were increased threefold in MF patients compared with those in healthy controls. In skin, CCL18 was specifically expressed by CD163(+) CD209(+) macrophages at the invasive margin of the tumor and not expressed by mature CD208(+) dendritic cells in the center of the tumor. The chemokine CCL17 was, by contrast, ubiquitously expressed. Furthermore, CCL18 promoted the chemotaxis but not the proliferation of CTCL cells. CCL18 inhibited proliferation of tumor cells and abolished the CXCL12-induced growth of a CTCL cell line. These data link the increased expression of CCL18 with CTCL and suggest an immunomodulatory effect of the chemokine in the pathogenesis of CTCL.     

趋化因子CCL22 和CCL20 协同皮肤抗原诱导的调节性T 淋巴细胞对皮肤移植的影响

目的:研究小鼠皮肤移植模型中趋化因子CCL20 和CCL22 联合调节性T 细胞对移植皮肤存活时间的影响。方法:将皮肤移植小鼠分为四组,每组3 只小鼠,分别为Treg 组、Treg+ CCL20 组、Treg+ CCL22 组与对照组。其中Treg 细胞经同种异体皮肤抗原诱导。以C57BL/6 小鼠为同种异体供体,BALB/ c 小鼠为受体行皮肤移植手术。进行皮肤移植后立即于异体皮下注射Treg 细胞2伊105 个细胞/ 鼠,体积为200 滋l。以后每日于异体皮下注射趋化因子CCL20 或CCL22,共连续注射10 d,观察并记录皮肤的存活情况。Treg 细胞定植实验:首先利用磁珠分选方法分离皮肤抗原诱导Treg 细胞,并利用锝99 标记分离到的Treg 细胞;皮下注射3 h 后,处死小鼠,用GC-2016酌放射免疫计数器检测各脏器及移植皮肤的放射性活度。结果:淤经Treg 进行干预的小鼠,其异体皮肤存活时间均显著长于手术对照组(P<0.05),而且同种异体抗原诱导Treg 在趋化因子CCL20 或CCL22 存在下异体皮肤存活时间显著高于单纯使用Treg 组和对照组(P<0.001)。于注射皮肤抗原诱导的Treg 细胞后,自体和异体皮肤移植组Treg 细胞主要分布在自体和异体皮肤,分别占注射Treg 组细胞的60%和98%;加趋化因子CCL20组和CCL22 组的Treg 主要分布在肝脏。结论:趋化因子CCL20 和CCL22 能够协同促进经皮肤抗原诱导的Treg 细胞延长异体皮肤的存活时间,这种作用效果可能与趋化因子CCL20 和CCL22 趋化Treg 细胞向肝脏大量定植相关。     

Specific skin tests in subjects with chronic bronchitis exposed to pigeons

We have studied the diagnostic reliability of the specific skin tests done in 30 subjects who presented with chronic bronchitis (CB) as the only clinical manifestation related to exposure to pigeons and in 21 subjects with CB and known risk factors. Additionally, two control groups were included (24 asymptomatic subjects exposed and sensitized to pigeons and 10 subjects not exposed and not sensitized to pigeons). The skin prick tests with pigeon scrum were negative in all the subjects tested. The intradermal skin tests showed an immediate positive reaction in 16 of the 30 CB-affected patients and in six of the control group of exposed asymptomatic subjects (chi square: 3.376) ( P <0.1; nearly significant); after 6 h, a positive reaction was recorded in 14 of the CB-affected patients and in three subjects of the control group (chi square: 5.187) ( P < 0.005). A delayed reaction was seen in 10/30 CB patients and in only three of the 24 subjects of the control group (chi square: 2.218) (nonsignificant). In the group of the 21 CB patients with known risk factors and not sensitized to pigeons, only two patients showed immediate skin reactivity; the remaining readings were negative. Lastly, in the control group of 10 unexposed, nonsensitized subjects, the intradermal skin tests in the different readings were negative. Our results show that although the skin tests with pigeon serum have low sensitivity, they can be a useful supplement in distinguishing cases of CB attributable to chronic pigeon exposure from those cases attributable to another cause, especially in the consideration of immediate and late readings.     

Abrogation of CCL21 chemokine function by transgenic over-expression impairs T cell immunity to local infections

The CC chemokine receptor 7 (CCR7) and its two ligands, CCL21 and CCL19, play an important role in migration of immune cells to lymphoid tissue. To analyze the function of CCR7 in T cell immunity to infectious agents in vivo, transgenic (tg) mice expressing CCL21 in an ubiquitous fashion were generated. These mice contained high amounts of CCL21 in the serum ( approximately 0.3 microg/ml that resulted in CCR7 down-regulation and in a strongly impaired migration of T cells toward CCL21 in vitro. Lymph nodes in CCL21-tg mice were reduced in size but with intact microanatomy and normal distribution of T and B cells. CCL21-tg mice showed a significantly decreased CD8 T cell response to lymphocytic choriomeningitis virus after footpad infection, whereas the response after systemic infection was not altered. Likewise, the CD4 T cell response to footpad infection with Leishmania major was considerably lowered and CCL21-tg mice failed to clear parasites from infected skin. Taken together, these data demonstrate the importance of CCR7 in mediating T cell immunity to viral and parasitic pathogens after local infection.     

Secondary lymphoid tissue chemokine (CCL21) is upregulated in allergic contact dermatitis

Chemokines are important players in the development of allergic contact dermatitis (ACD). The participation of secondary lymphoid tissue chemokine (CCL21) is essential in the induction of the disease due to its expression in lymphatic vessels and in secondary lymphoid organs. Since there is no information about its participation during the effector phase of ACD, we studied this chemokine in patients already diagnosed with ACD, who were challenged with the relevant positive and negative (control) antigens. All patients showed a specific antigen-induced immune response characterized by early expression of inflammatory markers in blood endothelial cells followed by dermal accumulation of mononuclear cells with an important increase in infiltration of CXCR3+ but not of CCR7+ cells. In situ hybridization and immunohistochemistry showed low levels of CCL21 in lymphatic vessels at 2 h, whereas they were significantly increased at 10 and 48 h in all positive patch tests. In contrast, very low expression of this chemokine was observed in skin biopsies from the control site at 48 h. In addition, Langerin+ cells, which were present in dermis from positive patch tests at 2 h, were diminished in number at 10 and 48 h, but a significant number of those cells was still present in dermal areas of the control site at 48 h. We demonstrate for the first time that CCL21, a constitutively expressed chemokine, is strongly upregulated in human lymphatic vessels during a Th1/Tc1 allergic inflammatory response. This can provide the signal required for CCR7+ cells to leave the skin through CCL21-positive lymphatic vessels.     

Up-regulation of chemokine C-C ligand 2 (CCL2) and C-X-C chemokine 8 (CXCL8) expression by monocytes in chronic idiopathic urticaria

The disturbed cytokine-chemokine network could play an important role in the onset of diseases with inflammatory processes such as chronic idiopathic urticaria (CIU). Our main objectives were to evaluate the relation between proinflammatory chemokine serum levels from CIU patients and their response to autologous skin test (ASST) and basophil histamine release (BHR). We also aimed to assess the chemokine secretion by peripheral blood mononuclear cells (PBMC) upon polyclonal stimulus and to evaluate chemokine C-C ligand 2/C-X-C chemokine 8 (CCL2/CXCL8) and Toll-like receptor-4 (TLR-4) expression in monocytes. We observed significantly higher serum levels of the CXCL8, CXCL9, CXCL10 and CCL2 in CIU patients compared to the healthy group, regardless of the BHR or ASST response. The basal secretion of CCL2 by PBMC or induced by Staphylococcus aureus enterotoxin A (SEA) was higher in CIU patients than in the control group, as well as for CXCL8 and CCL5 secretions upon phytohaemagglutinin stimulation. Also, up-regulation of CCL2 and CXCL8 mRNA expression was found in monocytes of patients upon SEA stimulation. The findings showed a high responsiveness of monocytes through CCL2/CXCL8 expression, contributing to the creation of a proinflammatory environment in CIU.     

Up-regulation of CCL17, CCL22 and CCR4 in drug-induced maculopapular exanthema

BACKGROUND: Maculopapular exanthema has been reported to be the most frequently drug-induced cutaneous reaction. Although T lymphocytes are involved in the pathomechanism of this disease, little is know about the recruitment of these cells to the skin. OBJECTIVE: The aim of this work is to study the role of the chemokines TARC/CCL17 and MDC/CCL22 in the lymphocyte trafficking to affected skin in drug-induced exanthemas. METHODS: Real-time PCR was performed to quantify gene expression levels of CCL17, CCL22 and their receptor CCR4 in lesional skin biopsies and in peripheral blood mononuclear cells from patients. CCL27 and CCL22 proteins were detected in the skin by immunochemistry. Protein expression of CCR4 was determined by flow cytometry in peripheral blood lymphocytes. Functional migration assays to CCL17 and CCL22 were assessed to compare the migratory responses of peripheral blood lymphocytes from patients and healthy subjects. RESULTS: CCL17 and CCL22 were up-regulated in maculopapular exanthema-affected skin. CCR4 mRNA levels and protein expression were increased in peripheral blood mononuclear cells during the acute phase of the disease. The increased expression of the receptor was consistent with a higher response of peripheral blood lymphocytes to CCL17 and CCL22 compared with the migratory response in healthy donors. CONCLUSION: TARC/CCL17 and MDC/CCL22 might cooperate in attracting T lymphocytes to skin in drug-induced maculopapular exanthemas.     

Up-regulation of CCL11 and CCL26 is associated with activated eosinophils in bullous pemphigoid

Eosinophils contribute to the pathogenesis of bullous pemphigoid (BP) by secretion of proinflammatory cytokines and proteases. Trafficking of eosinophils into tissue in animal models and asthma depends on interleukin-5 and a family of chemokines named eotaxins, comprising CCL11, CCL24 and CCL26. Up-regulation of CCL11 has been described in BP, but the expression of the other two members of the eotaxin-family, CCL24 and CCL26, has not been investigated. In addition to these chemokines, expression of adhesion molecules associated with eosinophil migration to the skin should be analysed. We demonstrate that similar to CCL11, the concentration of CCL26 was up-regulated in serum and blister fluid of BP patients. In contrast, the concentration of CCL24 was not elevated in sera and blister fluid of the same BP patients. In lesional skin, CCL11 and CCL26 were detected in epidermis and dermis by immunohistochemistry. In contrast to CCL11, CCL26 was expressed strongly by endothelial cells. In line with these findings, eosinophils represented the dominating cell population in BP lesional skin outnumbering other leucocytes. The percentage of eosinophils expressing very late antigen (VLA): VLA-4 (CD49d) and CD11c correlated with their quantity in tissue. Macrophage antigen (MAC)-1 (CD11b/CD18) was expressed constitutively by tissue eosinophils. In conclusion, these data link the up-regulation of the eosinophil chemotactic factor CCL26 in BP to the lesional accumulation of activated eosinophils in the skin. Thereby they broaden the understanding of BP pathogenesis and might indicate new options for therapeutic intervention.     

Induction of angiogenic chemokine CCL2 by human herpesvirus 8 chemokine receptor

Human herpesvirus 8 (HHV-8) is associated with Kaposi's sarcoma (KS), an endothelial cell lesion believed to be initiated and driven primarily by cytokine dysregulation. Among the viral proteins suspected as contributing to viral pathogenesis is the lytically expressed viral G protein-coupled receptor (vGPCR), which can induce various cellular cytokines. CC ligand-2 (CCL2/MCP-1) is a vGPCR-regulated angiogenic chemokine found at elevated levels in KS lesions and induced by HHV-8 infection of endothelial cells. Here we show that vGPCR induces CCL2 in endothelial cells via activation of C/EBPβ and that vGPCR and C/EBPβ are critical components of CCL2 induction by HHV-8 infection of endothelial cultures. To our knowledge, this is the first report of vGPCR-mediated cytokine induction, and its characterization, in the context of virus infection. Our results identify a mechanism by which vGPCR can contribute, in a host cell shutoff-independent manner, to viral pathogenesis.     

CCL21 is sufficient to mediate DC migration,maturation and function in the absence of CCL19

Mice deficient in CCR7 signals show severe defects in lymphoid tissue architecture and immune response. These defects are due to impaired attraction of CCR7⁺ DC and CCR7⁺ T cells into the T zones of secondary lymphoid organs and altered DC maturation. It is currently unclear which CCR7 ligand mediates these processes in vivo as CCL19 and CCL21 show an overlapping expression pattern and blocking experiments have given contradictory results. In this study, we addressed this question using CCL19‐deficient mice expressing various levels of CCL21. Complete deficiency of CCL19 and CCL21 but not CCL19 alone was found to be associated with abnormal frequencies and localization of DC in naïve LN. Similarly, CCL19 was not required for DC migration from the skin, full DC maturation and efficient T‐cell priming. Our findings suggest that CCL21 is the critical CCR7 ligand regulating DC homeostasis and function in vivo with CCL19 being redundant for these processes.     

The chemokine CCL18 causes maturation of cultured monocytes to macrophages in the M2 spectrum

The observation that human monocytes cultured in the presence of the chemokine CCL18 showed increased survival, led us to profile cytokine expression in CCL18-stimulated versus control cultures. CCL18 caused significantly increased expression of chemokines (CXCL8, CCL2, CCL3 and CCL22), interleukin-10 (IL-10) and platelet-derived growth factor, but no up-regulation of M1 cytokines IL-1β or IL-12. CCL18-stimulated monocytes matured into cells with morphological resemblance to IL-4-stimulated macrophages, and expressed the monocyte marker CD14 as well the M2 macrophage markers CD206 and 15-lipoxygenase, but no mature dendritic cell markers (CD80, CD83 or CD86). Functionally, CCL18-stimulated macrophages showed a high capacity for unspecific phagocytosis and for pinocytosis, which was not associated with an oxidative burst. These findings suggest that CCL18-activated macrophages stand at the cross-roads between inflammation and its resolution. The chemokines that are produced in response to CCL18 are angiogenic and attract various leucocyte populations, which sustain inflammation. However, the capacity of these cells to remove cellular debris without causing oxidative damage and the production of the anti-inflammatory IL-10 will initiate termination of the inflammatory response. In summary, CCL18 induces an M2 spectrum macrophage phenotype in the absence of IL-4.     

Hepatic expression of secondary lymphoid chemokine (CCL21) promotes the development of portal-associated lymphoid tissue in chronic inflammatory liver disease

The chronic inflammatory liver disease primary sclerosing cholangitis (PSC) is associated with portal inflammation and the development of neolymphoid tissue in the liver. More than 70% of patients with PSC have a history of inflammatory bowel disease and we have previously reported that mucosal addressin cell adhesion molecule-1 is induced on dendritic cells and portal vascular endothelium in PSC. We now show that the lymph node-associated chemokine, CCL21 or secondary lymphoid chemokine, is also strongly up-regulated on CD34(+) vascular endothelium in portal associated lymphoid tissue in PSC. In contrast, CCL21 is absent from LYVE-1(+) lymphatic vessel endothelium. Intrahepatic lymphocytes in PSC include a population of CCR7(+) T cells only half of which express CD45RA and which respond to CCL21 in migration assays. The expression of CCL21 in association with mucosal addressin cell adhesion molecule-1 in portal tracts in PSC may promote the recruitment and retention of CCR7(+) mucosal lymphocytes leading to the establishment of chronic portal inflammation and the expanded portal-associated lymphoid tissue. This study provides further evidence for the existence of portal-associated lymphoid tissue and is the first evidence that ectopic CCL21 is associated with lymphoid neogenesis in human inflammatory disease.     

Role of CCL21 and CCL19 in allergic inflammation in the ovalbumin-specific murine asthmatic model

BACKGROUND: Dendritic cells are the most powerful of the antigen-presenting cells and are known to play important roles in sensitization and inflammation in allergen-specific asthma. Various cytokines and chemokines are involved in the maturation and activation of dendritic cells. Among them is CC chemokine ligand (CCL)21, a key chemokine in the entry of naive T cells and antigen-stimulated dendritic cells into the T-cell zones of secondary lymphoid organs, which is a critical process in antigen-specific T-cell activation. OBJECTIVE: We studied the role of CCL21 in airway inflammation in asthma by using BALB/c-plt/plt (plt) mice, which possess genetic defects in expression of both CCL21 and CCL19. METHODS: Plt and control BALB/c mice were immunized with ovalbumin and alum 4 times and thereafter were subjected to a 2-week regimen of ovalbumin inhalation. RESULTS: In plt mice, ovalbumin-specific IgE response was delayed compared with control BALB/c mice, but they had the same level of response after final immunization. Although airway inflammation and response to acetylcholine were significantly reduced compared with BALB/c mice, significant eosinophilic inflammation and hyperresponsiveness were also observed in plt mice after 2 weeks of inhalation. Four weeks after cessation of inhalation, airway inflammation and hyperresponsiveness in plt mice were greater than in BALB/c mice. At the time of resolution of airway inflammation, IL-10 production was enhanced in BALB/c mice but not in plt mice. CONCLUSION: The chemokines CCL21 and CCL19 were critical for resolution of airway inflammation. CLINICAL IMPLICATIONS: The findings about the chemokines for induction and resolution of inflammation are key to establishing a new strategy for asthma immunotherapy.     

The role of CCL22/macrophage-derived chemokine in allergic rhinitis

Dendritic cells (DCs) are considered to be the most powerful antigen-presenting cells (APCs). DCs are thought to be associated with Th1 or Th2 polarization and with polarization-induced disease such as atopic dermatitis, asthma and allergic rhinitis, but its mechanism is not well known. In this study, we analyzed the mRNA expression of DCs between birch pollen allergic rhinitis and healthy controls by using cDNA array. We found that the expressions of CCL22/macrophage-derived chemokine (MDC) differed significantly. We also revealed that CCL22/MDC production was higher in patients than in healthy donors. By chemotaxis assay, CCL22/MDC can enhance the migration of patient's T cells rather than those of healthy controls. Surface marker analysis of migrated cells revealed that the most of migrated cells expressed CCR4, which were considered to be Th2 cells. Furthermore, CD1a(+) CD83(+) cells located in the nasal mucosa expressed CCL22/MDC in vivo. To the best of our knowledge, this is the first report clearly indicating the role of CCL22/MDC in allergic rhinitis.     

Seasonal dynamics of chemokine receptors and CD62L in subjects with asymptomatic skin sensitization to birch and grass pollen

BACKGROUND: Asymptomatic skin sensitization (AS) has been shown to be a risk factor for respiratory allergic disease. CCR4, CXCR1 and CD62L have all been assigned a role in the immunopathogenesis of allergy. Memory T-cell expression of CCR4, CXCR1 and CD62L has not hitherto been investigated in subjects with AS. METHODS: We investigated seasonal CD4 memory T-cell expression of the chemokine receptors CCR4, CXCR1 as well as L-selectin (CD62L) in fresh cultures derived from symptomatic atopics (SAs), subjects with AS and healthy controls (HCs). Peripheral blood mononuclear cells from all three groups were isolated during birch and grass pollination as well as in the following winter. CD4 memory T-cell expression of CCR4, CXCR1 and CD62L was determined by flow-cytometry. RESULTS: During spring and summer, a significantly increased proportion of memory T cells expressed CCR4, CXCR1 and CD62L in SAs when compared with subjects with AS and HCs. Only SAs exhibited seasonal fluctuations in numbers of CCR4, CXCR1 and CD62L positive memory T cells. CONCLUSION: Although clearly IgE sensitized, subjects with AS have significant diminished numbers of CCR4, CXCR1 and CD62L positive memory T cells, during pollination, when compared with SAs. In contrast to SAs, cultures derived from subjects with AS did not display seasonal variation. Our findings explain the lack of clinical symptoms, during pollination, in subjects with AS.     

Involvement of the chemokine RANTES (CCL5) in resistance to experimental infection with Leishmania major

The expression and putative role of chemokines during infection with Leishmania major in mice were investigated. CCL5 expression correlates with resistance, and blockade of CCL5 rendered mice more susceptible to infection. CCL5 is part of the cascade of events leading to efficient parasite control in L. major infection.     

Penicillin skin testing in advance of need: multiyear follow-up in 568 test result-negative subjects exposed to oral penicillins

BACKGROUND: There are few published data on adverse drug reactions and/or resensitization associated with oral penicillin use in penicillin allergy history-positive/penicillin skin test-negative individuals during routine clinical care with multiyear follow-up. OBJECTIVES: We sought to provide long-term follow-up data on the type, severity, and frequency of adverse reactions associated with oral penicillin use in individuals who have histories of penicillin "allergy" yet also have negative results on penicillin skin tests done in advance of need. We also aimed to repeat testing on individuals with penicillin-associated adverse reactions. METHODS: Medical records were reviewed for penicillin use and associated adverse reactions in all 568 penicillin skin test-negative individuals who had received at least 1 course of oral penicillin after testing but before December 31, 2001, during routine care. These individuals were drawn from a group of 1246 penicillin skin test-negative individuals seen initially between November 16, 1994, and August 13, 2001. RESULTS: The mean length of follow-up was 4.26 +/- 1.64 years (range, 0.39-7.12 years). The mean penicillin exposure was 3.94 +/- 3.91 courses (range, 1-22 courses). Only 65 (11.4%) of 568 subjects had any penicillin-associated reactions, and 6 subjects had 2 reactions each. A reaction occurred in 27 subjects (4.8%) with their first penicillin reexposure. There were 71 (3.2%) reactions with 2236 total penicillin courses. There were no serious reactions. Repeated testing was done in 33 subjects older than age 18 years. Only 1 subject was positive on repeated penicillin skin testing. CONCLUSION: Penicillin use after negative penicillin skin testing done in advance of need is safe, and resensitization is rare.