CCL28 production in HaCaT cells was mediated by different signal pathways from CCL27

The Central Roles of Keratinocytes in Coordinating Skin Immunity

The function of keratinocytes (KCs) to form a barrier and produce cytokines is well-known, but recent progress has revealed many different roles for KCs in regulation of skin immunity. In this review, we provide an update on the current understanding of how KCs communicate with microbes, immunocytes, neurons, and other cells to form an effective immune barrier. We catalog the large list of genes and metabolites of KCs that participate in host defense and discuss the mechanisms of immune crosstalk, addressing how KCs simultaneously form a physical barrier, communicate with fibroblasts, and control immune signals. Overall, the signals sent and received by KCs are an exciting group of therapeutic targets to explore in the treatment of dermatologic disorders.

Polyopes affinis Suppressed IFN-γ- and TNF-α-Induced Inflammation in Human Keratinocytes via Down-Regulation of the NF-κB and STAT1 Pathways

Polyopes affinis is a red algal species commonly found on the South coast and near Jeju Island, Korea. This study aimed to determine whether P. affinis extracts can inhibit the pathogenesis of T-helper-2 (Th2)-mediated inflammation in a human keratinocyte cell line of atopic dermatitis (AD). Cells were incubated with 10 ng/mL of interferon gamma (IFN-γ) and 10 ng/mL of tumor necrosis factor-alpha (TNF-α) at various concentrations of PAB (10, 30, and 60 µg/mL) and PAA (100, 500, and 1000 µg/mL) extracts. A gene-ontology (GO)-enrichment analysis revealed that PAB significantly enriched the genes associated with biological processes such as cell adhesion, immune response, inflammation, and chemokine-mediated pathways. PAB suppressed the expression of the secretory proteins and mRNAs that are associated with the thymus and the production of activation-regulated chemokines (TARC/CCL17) and macrophage-derived chemokines (MDC/CCL22). The effect of the extract on mitogen-activated protein kinases (MAPKs) was related to its inhibition of TARC/CCL17 and MDC/CCL22 production by blocking NF-κB and STAT1 activation. These results suggest that seaweed extract may improve AD by regulating pro-inflammatory chemokines. In conclusion, we first confirmed the existence of phloroglucinol, a polyphenol formed from a precursor called phlorotannin, which is present in PAB, and this result proved the possibility of PAB being used as a treatment for AD.

CCL27 Signaling in the Tumor Microenvironment

Chemokines are a group of small proteins which play an important role in leukocyte migration and invasion. They are also involved in the cellular proliferation and migration of tumor cells.Chemokine CCL27 (cutaneous T cell-attracting chemokine, CTACK) is mainly expressed by keratinocytes of the normal epidermis. It is well known that this chemokine plays an important role in several inflammatory diseases of the skin, such as atopic dermatitis, contact dermatitis, and psoriasis. Moreover, several studies have shown an association between CCL27 expression and a variety of neoplasms including skin cancer.In this chapter, we address the role of chemokine CCL27 in the tumor microenvironment in the most relevant cancers of the skin and other anatomical locations. We also make a brief comment on future perspectives and the potential relation of CCL27 with different immunotherapeutic modalities.

Rosae multiflorae Fructus Extract Improves Trimellitic Anhydride-Induced Atopic Dermatitis-Like Symptoms

Allergic disorders, including atopic dermatitis (AD), are closely linked to the activation of type 2 helper T (Th2) cells. The aim of this study was to investigate the possibility of using Rosae multiflorae fructus extract (RMFE) for AD treatment in the AD-like mouse model induced by treatment with trimellitic anhydride (TMA). Oral treatment of RMFE reduced the increase in ear thickness and suppressed inflammatory cytokine expression (interleukin [IL]-1β and tumor necrosis factor [TNF]-α) and Th2-associated immune responses (immunoglobulin [Ig] E and IL-4) in mouse ears. Furthermore, messenger RNA (mRNA) expression levels such as IL-4, IL-5, and IL-13, in draining lymph nodes were decreased by RMFE. Furthermore, we found that RMFE increased the level of heme oxygenase-1 (HO-1) through ERK and p38 pathways, reducing IL-2 production and CD4⁺ T cell proliferation, and inhibited STAT6 phosphorylation. Therefore, this study suggested that RMFE could be an effective treatment of AD induced by Th2-mediated immune responses by suppressing proliferation of CD4⁺ T cells via increased HO-1.

Therapeutic potential of topically administered γ-AlOOH on 2,4-dinitrochlorobenzene-induced atopic dermatitis-like lesions in Balb/c mice

Boehmite (γ-AlOOH) has a wide range of applications in a variety of industrial and biological fields. However, little is known about its potential roles in skin diseases. The current study investigated its effect on atopic dermatitis (AD). Following characterization, cytotoxicity, pro-inflammatory response and oxidative stress associated with boehmite were assessed, using TNF-α-induced keratinocytes and mast cells. In addition, therapeutic effects of boehmite, topically administered to Balb/c mice induced by 2,4-dinitrochlorobenzene (DNCB), were evaluated. Expression of cytokines (TLSP, IL-25 and IL-33) and the generation of ROS from keratinocytes induced by TNF-α were significantly inhibited by boehmite without affecting cell viability. MAPKs (ERK, JNK and p38) required for cytokine expression were suppressed by boehmite treatment. Up-regulation of cytokines (TSLP, IL-4, IL-5, IL-13, RANTES) in human mast cells treated with phorbol 12-myristate 13-acetate and calcium ionophore was also suppressed by boehmite. Boehmite improved the AD severity score, epidermal hyperplasia and transepidermal water loss in DNCB-induced AD-like lesions. Moreover, Th2-mediated cytokine expression, mast cell hyperplasia and destruction of the skin barrier were improved by boehmite treatment. Overall, we demonstrated that boehmite may potentially protect against AD.

Chemokines cooperate with TNF to provide protective anti-viral immunity and to enhance inflammation

The role of cytokines and chemokines in anti-viral defense has been demonstrated, but their relative contribution to protective anti-viral responses in vivo is not fully understood. Cytokine response modifier D (CrmD) is a secreted receptor for TNF and lymphotoxin containing the smallpox virus-encoded chemokine receptor (SECRET) domain and is expressed by ectromelia virus, the causative agent of the smallpox-like disease mousepox. Here we show that CrmD is an essential virulence factor that controls natural killer cell activation and allows progression of fatal mousepox, and demonstrate that both SECRET and TNF binding domains are required for full CrmD activity. Vaccination with recombinant CrmD protects animals from lethal mousepox. These results indicate that a specific set of chemokines enhance the inflammatory and protective anti-viral responses mediated by TNF and lymphotoxin, and illustrate how viruses optimize anti-TNF strategies with the addition of a chemokine binding domain as soluble decoy receptors.

CCR10/CCL27 crosstalk contributes to failure of proteasome-inhibitors in multiple myeloma

The bone marrow microenvironment plays a decisive role in multiple myeloma progression and drug resistance. Chemokines are soluble mediators of cell migration, proliferation and survival and essentially modulate tumor progression and drug resistance. Here we investigated bone marrow-derived chemokines of naive and therapy-refractory myeloma patients and discovered that high levels of the chemokine CCL27, known so far for its role in skin inflammatory processes, correlated with worse overall survival of the patients. In addition, chemokine levels were significantly higher in samples from patients who became refractory to bortezomib at first line treatment compared to resistance at later treatment lines.

In vitro as well as in an in vivo model we could show that CCL27 triggers bortezomib-resistance of myeloma cells. This effect was strictly dependent on the expression of the respective receptor, CCR10, on stroma cells and involved the modulation of IL-10 expression, activation of myeloma survival pathways, and modulation of proteasomal activity. Drug resistance could be totally reversed by blocking CCR10 by siRNA as well as blocking IL-10 and its receptor.

From our data we suggest that blocking the CCR10/CCL27/IL-10 myeloma-stroma crosstalk is a novel therapeutic target that could be especially relevant in early refractory myeloma patients.

CCL28 promotes breast cancer growth and metastasis through MAPK-mediated cellular anti-apoptosis and pro-metastasis

Breast cancer is one of the most commonly diagnosed cancers worldwide and the second leading cause of cancer-related deaths among females. CCL28 (mucosa-associated epithelial chemokine, MEC), a CC subfamily chemokine, has been well studied in the process of inflammation, and recently increasing evidence indicates that CCL28 is related to tumor progression. However, little is known concerning its function in breast cancer. In the present study, we generated a CCL28-overexpressing breast cancer cell line MDA-MB-231HM/CCL28 from parental MDA-MB-231HM cells. We found that overexpression of CCL28 promoted cell proliferation and tumor formation, and also enhanced migration, invasion and metastasis both in vitro and in vivo. Mechanistic studies revealed that CCL28 mediated intracellular activation of the mitogen-activated protein kinase (MAPK) signaling pathway to promote breast cancer cell proliferation and metastasis by upregulating anti-apoptotic protein Bcl-2 and suppressing cell adhesion protein β-catenin. However, overexpression of CCL28 did not influence the expression of metastasis-related protein matrix metalloproteinase MMP2 and MMP9 and VEGF. Tissue sample analysis from animal models also indicated that overexpression of CCL28 was associated with enhanced pERK expression and reduced β-catenin expression in breast carcinomas. Thus, our results show for the first time that CCL28 contributes to breast cancer progression through the ERK/MAPK-mediated anti-apoptotic and metastatic signaling pathway. Antagonists of CCL28 and the MAPK signaling pathway may be used synergistically to treat breast cancer patients.

Inhibitory effect of tumor suppressor p53 on proinflammatory chemokine expression in ovarian cancer cells by reducing proteasomal degradation of IκB

Ovarian cancer, one of inflammation-associated cancers, is the fifth leading cause of cancer deaths among women. Inflammation in the tumor microenvironment is associated with peritoneal tumor dissemination and massive ascites, which contribute to high mortality in ovarian cancer. Tumor suppressor p53 is frequently deleted or mutated in aggressive and high-grade ovarian cancer, probably aggravating cancer progression and increasing mortality. We therefore investigated the influence of p53 on proinflammatory chemokines in ovarian cancer cells. A PCR array of the chemokine network revealed that ovarian cancer cells with low or mutated p53 expression expressed high levels of proinflammatory chemokines such as CXCL1, 2, 3 and 8. Transient transfection of p53 into p53-null ovarian cancer cells downregulated proinflammatory chemokines induced by tumor necrosis factor-α (TNF), a proinflammatory cytokine abundantly expressed in ovarian cancer. Furthermore, p53 restoration or stabilization blocked TNF-induced NF-κB promoter activity and reduced TNF-activated IκB. Restoration of p53 increased ubiquitination of IκB, resulting from concurrently reduced proteasome activity followed by stability of IκB. A ubiquitination PCR array on restoration of p53 did not reveal any significant change in expression except for Mdm2, indicating that the balance between p53 and Mdm2 is more important in regulating NF-κB signaling rather than the direct effect of p53 on ubiquitin-related genes or IκB kinases. In addition, nutlin-3, a specific inducer of p53 stabilization, inhibited proinflammatory chemokines by reducing TNF-activated IκB through p53 stabilization. Taken together, these results suggest that p53 inhibits proinflammatory chemokines in ovarian cancer cells by reducing proteasomal degradation of IκB. Thus, frequent loss or mutation of p53 may promote tumor progression by enhancing inflammation in the tumor microenvironment.

CCR10 and its ligands in regulation of epithelial immunity and diseases

Epithelial tissues covering the external and internal surface of a body are constantly under physical, chemical or biological assaults. To protect the epithelial tissues and maintain their homeostasis, multiple layers of immune defense mechanisms are required. Besides the epithelial tissue-resident immune cells that provide the first line of defense, circulating immune cells are also recruited into the local tissues in response to challenges. Chemokines and chemokine receptors regulate tissue-specific migration, maintenance and functions of immune cells. Among them, chemokine receptor CCR10 and its ligands chemokines CCL27 and CCL28 are uniquely involved in the epithelial immunity. CCL27 is expressed predominantly in the skin by keratinocytes while CCL28 is expressed by epithelial cells of various mucosal tissues. CCR10 is expressed by various subsets of innate-like T cells that are programmed to localize to the skin during their developmental processes in the thymus. Circulating T cells might be imprinted by skin-associated antigen- presenting cells to express CCR10 for their recruitment to the skin during the local immune response. On the other hand, IgA antibody-producing B cells generated in mucosa-associated lymphoid tissues express CCR10 for their migration and maintenance at mucosal sites. Increasing evidence also found that CCR10/ligands are involved in regulation of other immune cells in epithelial immunity and are frequently exploited by epithelium-localizing or -originated cancer cells for their survival, proliferation and evasion from immune surveillance. Herein, we review current knowledge on roles of CCR10/ligands in regulation of epithelial immunity and diseases and speculate on related important questions worth further investigation.

CCL27 expression is regulated by both p38 MAPK and IKKβ signalling pathways

The skin-specific chemokine CCL27 is believed to play a pivotal role in establishing the inflammatory infiltrate characteristic for common inflammatory skin diseases. Through binding to the chemokine receptor 10 (CCR10), CCL27 mediates inflammation by promoting lymphocyte migration into the skin. Little is known about the regulation of CCL27 gene expression. The purpose of our study was to investigate the regulation of the IL-1β-induced CCL27 gene expression in normal human keratinocytes (NHEK). Preincubation of NHEK with the inhibitory κB (IκB) kinase (IKK) inhibitor, SC-514, or the p38 mitogen-activated protein kinase (MAPK) inhibitor, SB202190, revealed a profound reduction in both CCL27 mRNA and CCL27 protein expression indicating the significance of these pathways in the regulation of CCL27 expression. Furthermore, the impact of inhibitors of mitogen- and stress-activated kinase 1 (MSK1) or the mitogen-activated protein kinase-interacting kinases (Mnk1+2), downstream kinases of p38 MAPK, on IL-1β-induced CCL27 expression in NHEK were investigated. We identified seven NF-κB binding elements upstream from the CCL27 gene start codon using electrophoretic mobility shift assay (EMSA). Supershift analyses demonstrated the involvement of the p50/p65 NF-κB heterodimer. We conclude that IL-1β-induced CCL27 gene expression in NHEK is regulated through the p38 MAPK/MSK1/Mnk1+2 as well as the IKKβ/NF-κB signalling pathways.

(2S)-2′-methoxykurarinone from Sophora flavescens suppresses cutaneous T cell-attracting chemokine/CCL27 expression induced by interleukin-ß/tumor necrosis factor-α via heme oxygenase-1 in human keratinocytes

One of the CC chemokines, cutaneous T cell-attracting chemokine (CTACK/CCL27), is a skin-specific CC chemokine that is produced constitutively by keratinocytes and is highly up-regulated in inflammatory skin conditions such as atopic dermatitis and contact dermatitis. (2S)-2′-Methoxykurarinone (MOK) from Sophora flavescens has been demonstrated to have antioxidant effects. Heme oxygenase (HO)-1 has recently emerged as an important cytoprotective enzyme against oxidative stress and inflammatory responses in many cell types. This study aimed to define whether and how MOK regulates skin specific CTACK/CCL27 chemokine production in human HaCaT keratinocytes. The level of CTACK/CCL27 and HO-1 expression was measured by reverse transcription-polymerase chain reaction, and signaling was evaluated by western blot analysis. CTACK/CCL27 production was determined by enzyme-linked immunosorbent assay. Pretreatment with MOK suppressed tumor necrosis factor-α (TNF-α)- and interleukin (IL)-1ß-induced CTACK/CCL27 production in human HaCaT keratinocytes. MOK inhibited TNF-α- and IL-1ß-induced nuclear factor κB (NF-κB) activation. Interestingly, pretreatment with MOK significantly suppressed TNF-α- and IL-1ß-induced CTACK/CCL27 production through the induction of HO-1. This suppression was completely abolished by HO-1 small interfering RNA. Furthermore, carbon monoxide, but not other end products of HO-1 activity, also suppressed TNF-α- and IL-1ß-induced CTACK/CCL27 production. These results demonstrate that MOK attenuates TNF-α- and IL-1ß-induced production of CTACK/CCL27 in human HaCaT keratinocytes by inhibiting NF-κB activation and induction of HO-1.

CCR10 and CCL27 are overexpressed in cutaneous squamous cell carcinoma

C-C chemokine receptor (CCR)10 is a specific receptor for chemokine ligand (CCL)27, a selective chemoattractant for skin-associated memory T cells to cutaneous sites. In melanoma, CCR10 increases the ability of neoplastic cells to grow, invade tissues, disseminate to lymph nodes, and escape the host immune responses. In this study, we investigated the expression of CCR10 and its ligand CCL27 in squamous cell carcinoma (SCC). CCR10 and CCL27 were expressed in SCC, actinic keratosis (AK), Bowen's disease, and seborrheic keratosis (predominantly prickle cell type), but not in seborrheic keratosis (predominantly basal cell type) and basal cell carcinoma. Furthermore, CCR10 and CCL27 were overexpressed in SCC relative to Bowen's disease, an early stage of SCC. Consistently, a human SCC cell line, A253 cells, and HaCaT cells exhibited CCL27 production that was strongly induced by tumor necrosis factor-α and interleukin-1β. Finally, A253 cells expressed stronger intracellular CCR10 compared to HaCaT cells by flow cytometry. These results suggest that CCR10 and CCL27 overexpression in SCC is related to the progression of SCC and is useful for the diagnosis of SCC.

Identification of the signaling pathway of TNF-α-induced CCL17/TARC transcription in a canine keratinocyte cell line

A CC chemokine, CCL17/TARC, has been shown to be a factor in the immunopathogenesis of canine atopic dermatitis (cAD). In canine keratinocytes, the transcription of CCL17 mRNA is preferentially induced by tumor necrosis factor-alpha (TNF-α); however, its regulatory mechanism has not been elucidated. The aim of the present study is to clarify the regulatory mechanism of TNF-α-induced CCL17 mRNA transcription in canine keratinocytes leading to the development of a chemokine-targeted therapy for cAD. In a cell line of canine epidermal keratinocyte, CPEK, stimulation with TNF-α induced not only the activation of nuclear factor-kappa B (NF-κB) but also the phosphorylation of c-Jun-N-terminal kinase (JNK) and mitogen-activated protein kinase p38 (p38). Extracellular signal-regulated kinase (ERK) was found to be constitutively phosphorylated, which was temporarily augmented by TNF-α. Results of the inhibition assay indicated that the CCL17 mRNA transcription level was significantly decreased by p38 inhibitors but was not altered by either JNK or NF-κB inhibitors. Surprisingly, the ERK inhibitor increased the transcription level of CCL17 mRNA. Stimulation with epidermal growth factor (EGF), an ERK activator, suppressed the transcription of CCL17 mRNA. The present results suggest that TNF-α-induced CCL17 mRNA transcription in CPEK is positively regulated by p38 but negatively controlled by ERK.

Roxithromycin downregulates production of CTACK/CCL27 and MIP-3α/CCL20 from epidermal keratinocytes

Cutaneous T cell-attracting chemokine (CTACK)/CCL27 and macrophage inflammatory protein (MIP)-3α/CCL20 are the major inflammatory chemokines involved in skin inflammation. The present study showed that roxithromycin (RXM) suppressed the TNFα-induced production of CCL27 and CCL20 in HaCaT keratinocytes and normal human keratinocytes (NHKs) in a dose-dependent manner. The production of CCL20 induced by TNFα was suppressed by the addition of inhibitors of nuclear factor kappa B (NFκB). RXM suppressed NFκB activity induced by TNFα. RXM, by regulating CCL27 and CCL20, may contribute to the modulation of inflammation.

Augmentation of CCL17 and CCL28 gene expression by TNF-alpha, IL-1beta, or IFN-gamma in cultured canine keratinocytes

Keratinocytes produce inflammatory mediators that are involved in the pathogenesis of skin disorders such as atopic dermatitis (AD). In particular, the CC chemokines, thymus and activation regulated chemokine (TARC)/CCL17 and mucosae-associated epithelial chemokine (MEC)/CCL28 are considered to play an important role in the lesional infiltration of lymphocytes in canine AD. However, there have been no reports on the regulatory mechanisms of CCL17 and CCL28 transcription in canine keratinocytes. In this study, we investigated whether CCL17 and CCL28 transcription in cultured keratinocytes is induced by TNF-alpha, IL-1beta, or IFN-gamma. It was found that CCL17 mRNA transcription is augmented by TNF-alpha only, whereas the CCL28 mRNA level could be increased by TNF-alpha, IL-1beta, or IFN-gamma. The present study suggests that pro-inflammatory cytokines are important inducing factors for the production of CCL17 and CCL28 in the lesional skin of dogs with AD.

Human chorionic gonadotropin attracts regulatory T cells into the fetal-maternal interface during early human pregnancy

Regulatory T cells (Treg) expand during pregnancy and are present at the fetal-maternal interface at very early stages in pregnancy. The migration mechanisms of Treg to the pregnant uterus are still unclear. Human chorionic gonadotropin (hCG) is secreted by the blastocyst immediately after fertilization and has chemoattractant properties. Therefore, we sought to analyze whether hCG secreted by early trophoblasts attracts Treg to the uterus and hence contributes to maternal tolerance toward the fetus. Decidua and placenta tissue samples from patients having spontaneous abortions or ectopic pregnancies were employed to evaluate Treg and hCG levels. Age-matched samples from normal pregnant women served as controls. We further performed in vitro studies with primary first trimester trophoblast cells and a choriocarcinoma cell line (JEG-3) aiming to evaluate the ability of secreted hCG to attract Treg. Patients having miscarriages or ectopic pregnancy presented significantly decreased hCG mRNA and protein levels associated with decreased Foxp3, neuropilin-1, IL-10, and TGF-beta mRNA levels as compared with normal pregnant women. Using migration assays we demonstrated that Treg were attracted by hCG-producing trophoblasts or choriocarcinoma cells. Treg migration toward cells transfected with hCG expression vectors confirmed the chemoattractant ability of hCG. Our data clearly show that hCG produced by trophoblasts attracts Treg to the fetal-maternal interface. High hCG levels at very early pregnancy stages ensure Treg to migrate to the site of contact between paternal Ags and maternal immune cells and to orchestrate immune tolerance toward the fetus.

House dust mite major allergen Der f 1 enhances proinflammatory cytokine and chemokine gene expression in a cell line of canine epidermal keratinocytes

House dust mite (HDM) allergens are the most common allergens involved in the induction of IgE-mediated hypersensitivity. Recently, epicutaneous sensitization with HDM allergens has been emphasized in the development of atopic dermatitis (AD); however, direct stimulation of canine keratinocytes by mite allergens has not been well investigated. In the present study, we investigated the effects of Der f 1, a major allergen of Dermatophagoides farinae, on cytokine and chemokine gene expression in a canine keratinocyte cell line, CPEK. CPEK constitutively expressed mRNA for TNF-alpha, IL-12p35, IL-18, GM-CSF, TGF-beta, IL-8/CXCL8, TARC/CCL17, CTACK/CCL27 and MEC/CCL28. Of all the cytokines and chemokines investigated in CPEK, transcription levels of GM-CSF, IL-8/CXCL8 and TNF-alpha mRNA were significantly enhanced by stimulation with Der f 1. The present results suggest that Der f 1 can directly augment inflammatory cytokine and chemokine production from keratinocytes, and may initiate allergic inflammation independently of Type-I hypersensitivity.

CCR4 and CCR10 are expressed on epidermal keratinocytes and are involved in cutaneous immune reaction

CC chemokine ligand (CCL)17 and CCL27 produced by epidermal keratinocytes (KCs) recruit CC chemokine receptor (CCR)4 and CCR10 expressing T cells into the skin, respectively, resulting in enhanced skin inflammation. However, CCR4/CCL17 and CCR10/CCL27 interactions in epidermal KCs have not been investigated. The purpose of this study was to evaluate the role of the CCR4/CCL17 and CCR10/CCL27 loops in cutaneous immune reaction. Normal human KCs (NHKs) and HaCaT KCs expressed both CCR4 and CCR10 at mRNA and protein levels. CCR4 ligand CCL17 but not CCR10 ligand CCL27 induced production of IL-12 p40, granulocyte/monocyte colony-stimulating factor (GM-CSF) and nerve growth factor (NGF) by KCs. Both CCL17 and CCL27 induced migration of KCs in Boyden chamber assay and wound scratch assay. This study revealed that CCR4 and CCR10 are expressed on epidermal KCs and that both are functional in terms of skin cytokine production and/or migration to their ligand CCL17 and CCL27, respectively. Thus this study provided new insight into chemokine/chemokine receptors of KCs.

Epidermal chemokines and modulation by antihistamines, antibiotics and antifungals

Growing evidence has demonstrated that chemokines released from epidermal cells control inflammatory skin diseases. Keratinocytes elaborate both Th1- and Th2-associated chemokines, although the former is more abundantly produced than the latter. Downmodulation of keratinocyte production of chemokines is one of the therapeutic approaches for cutaneous inflammatory disorders. Recent observations have shown that keratinocyte chemokine production can be modulated by well-used drugs, including antihistamines, antibiotics and antifungals. Utilization of the beneficial side effects of these drugs may by clinically valuable.