Selective Expression of CCR10 and CXCR3 by Circulating Human Herpes Simplex Virus-Specific CD8 T Cells.

Herpes simplex virus (HSV) infection is restricted to epithelial cells and neurons and is controlled by CD8 T cells. These cells both traffic to epithelial sites of recurrent lytic infection and to ganglia and persist at the dermal-epidermal junction for up to 12 weeks after lesion resolution. We previously showed that cutaneous lymphocyte-associated antigen (CLA), a functional E-selectin ligand (ESL), is selectively expressed on circulating HSV-2-specific CD8 T cells. CLA/ESL mediates adhesion of T cells to inflamed vascular endothelium. Later stages in T-cell homing involve chemokines (Ch) and lymphocyte chemokine receptors (ChR) for vascular wall arrest and diapedesis. Several candidate ChR have been implicated in skin homing. We measured cell surface ChR on HSV-specific human peripheral blood CD8 T cells and extended our studies to HSV-1. We observed preferential cell surface expression of CCR10 and CXCR3 by HSV-specific CD8 T cells compared to CD8 T cells specific for control viruses, Epstein-Barr virus (EBV) and cytomegalovirus (CMV), and compared to bulk memory CD8 T cells. CXCR3 ligand mRNA levels were selectively increased in skin biopsy specimens from persons with recurrent HSV-2, while the mRNA levels of the CCR10 ligand CCL27 were equivalent in lesion and control skin. Our data are consistent with a model in which CCL27 drives baseline recruitment of HSV-specific CD8 T cells expressing CCR10, while interferon-responsive CXCR3 ligands recruit additional cells in response to virus-driven inflammation.IMPORTANCE HSV-2 causes very localized recurrent infections in the skin and genital mucosa. Virus-specific CD8 T cells home to the site of recurrent infection and participate in viral clearance. The exit of T cells from the blood involves the use of chemokine receptors on the T-cell surface and chemokines that are present in infected tissue. In this study, circulating HSV-2-specific CD8 T cells were identified using specific fluorescent tetramer reagents, and their expression of several candidate skin-homing-associated chemokine receptors was measured using flow cytometry. We found that two chemokine receptors, CXCR3 and CCR10, are upregulated on HSV-specific CD8 T cells in blood. The chemokines corresponding to these receptors are also expressed in infected tissues. Vaccine strategies to prime CD8 T cells to home to HSV lesions should elicit these chemokine receptors if possible to increase the homing of vaccine-primed cells to sites of infection.

Characterising the expression and function of CCL28 and its corresponding receptor, CCR10, in RA pathogenesis.

OBJECTIVE: This study was conducted to determine the expression pattern, regulation and function of CCL28 and CCR10 in rheumatoid arthritis (RA) pathogenesis. METHODS: Expression of CCL28 and CCR10 was assessed in RA compared with other arthritis synovial tissues (STs) or fluids (SFs) by histology or ELISA. The factors modulating CCL28 and CCR10 expression were identified in RA myeloid and endothelial cells by ELISA, FACS and Western blotting. The mechanism by which CCL28 ligation promotes RA angiogenesis was examined in control and CCR10-knockdown endothelial cell chemotaxis and capillary formation. RESULTS: CCL28 and/or CCR10 expression levels were accentuated in STs and SFs of patients with joint disease compared with normal controls and they were predominately coexpressed in RA myeloid and endothelial cells. We show that protein expression of CCL28 and CCR10 was modulated by tumour necrosis factor (TNF)-α and toll-like receptor 4 ligation in RA monocytes and endothelial cells and by interleukin (IL)-6 stimulation in RA macrophages. Neutralisation of CCL28 in RA SF or blockade of CCR10 on human endothelial progenitor cells (EPCs) significantly reduced SF-induced endothelial migration and capillary formation, demonstrating that ligation of joint CCL28 to endothelial CCR10+ cells is involved in RA angiogenesis. We discovered that angiogenesis driven by ligation of CCL28 to CCR10 is linked to the extracellular signal regulated kinase (ERK) cascade, as CCR10-knockdown cells exhibit dysfunctional CCL28-induced ERK signalling, chemotaxis and capillary formation. CONCLUSIONS: The overexpression of CCL28 and CCR10 in RA ST and their contribution to EPC migration into RA joints support the CCL28/CCR10 cascade as a potential therapeutic target for RA.

C-type lectin-like receptor LOX-1 promotes dendritic cell-mediated class-switched B cell responses.

Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) is a pattern-recognition receptor for a variety of endogenous and exogenous ligands. However, LOX-1 function in the host immune response is not fully understood. Here, we report that LOX-1 expressed on dendritic cells (DCs) and B cells promotes humoral responses. On B cells LOX-1 signaling upregulated CCR7, promoting cellular migration toward lymphoid tissues. LOX-1 signaling on DCs licensed the cells to promote B cell differentiation into class-switched plasmablasts and led to downregulation of chemokine receptor CXCR5 and upregulation of chemokine receptor CCR10 on plasmablasts, enabling their exit from germinal centers and migration toward local mucosa and skin. Finally, we found that targeting influenza hemagglutinin 1 (HA1) subunit to LOX-1 elicited HA1-specific protective antibody responses in rhesus macaques. Thus, LOX-1 expressed on B cells and DC cells has complementary functions to promote humoral immune responses.

Upregulation of chemokine receptor CCR10 is essential for glioma proliferation, invasion and patient survival.

Human gliomas are characterized by their invasion of normal brain structures irrespective of their grade of malignancy. Tumor cell invasion share many similarities with leukocyte trafficking, which is critically regulated by chemokines and their receptors. Here we report that the chemokine receptor CCR10 is highly expressed in human glioblastoma compared with control brain tissue. In vitro, signaling through CCL27-CCR10 mediates activation of p-Akt, and subsequently induces proliferation and invasive responses. Cell proliferation and invasion promoted by CCL27 were blocked by inhibition of p-Akt or CCR10. In vivo, down-regulation of CCR10 significantly impairs growth of glioma. Clinically, High CCR10 expression in GBM correlated with p-Akt, shorter overall survival and progression-free survival (P < 0.05). Together, these findings suggest that elevated CCR10 is a critical molecular event associated with gliomagenesis.

ERK-dependent downregulation of the atypical chemokine receptor D6 drives tumor aggressiveness in Kaposi sarcoma.

D6 is an atypical chemokine receptor acting as a decoy and scavenger for inflammatory CC chemokines expressed in lymphatic endothelial cells. Here, we report that D6 is expressed in Kaposi sarcoma (KS), a tumor ontogenetically related to the lymphatic endothelium. Both in human tumors and in an experimental model, D6 expression levels were inversely correlated with tumor aggressiveness and increased infiltration of proangiogenic macrophages. Inhibition of monocyte recruitment reduced the growth of tumors, while adoptive transfer of wild-type, but not CCR2(-/-) macrophages, increased the growth rate of D6-competent neoplasms. In the KS model with the B-Raf V600E-activating mutation, inhibition of B-Raf or the downstream ERK pathway induced D6 expression; in progressing human KS tumors, the activation of ERK correlates with reduced levels of D6 expression. These results indicate that activation of the K-Ras-B-Raf-ERK pathway during KS progression downregulates D6 expression, which unleashes chemokine-mediated macrophage recruitment and their acquisition of an M2-like phenotype supporting angiogenesis and tumor growth. Combined targeting of CCR2 and the ERK pathway should be considered as a therapeutic option for patients with KS.

High-dose vitamin D3 supplementation is a requisite for modulation of skin-homing markers on regulatory T cells in HIV-infected patients.

Vitamin D(3) is known to have an effect on the immune function. We investigated the immunomodulatory capability of vitamin D(3) in HIV-infected patients and studied the expression of chemokine receptors on regulatory T cells (Treg). Vitamin D(3)-deficient HIV-1-seropositive subjects were treated with cholecalciferol (vitamin D(3)) at a dose of 800 IU daily for 3 months (n=9) or 25,000 IU weekly for 2 months (n=7). Peripheral blood mononuclear cells (PBMCs) were isolated and analyzed for skin-homing (CCR4 and CCR10) and gut-homing (CCR9 and integrin α(4)ß(7)) marker expression on Treg, by flow cytometry, before and after supplementation. Serum 25(OH)D(3) and parathyroid hormone (PTH) levels were determined at baseline and after the treatment period. Weekly doses of 25,000 IU cholecalciferol effectively achieved the optimal target serum 25(OH)D(3) concentration of >75 nmol/liter (30 ng/ml) in HIV-infected patients. High-dose cholecalciferol supplementation differentially influenced skin-homing markers on Treg with an increased level of CCR10 expression and while a reduction in CCR4 expression level was observed together with a lower percentage of Treg expressing CCR4. For both dosing regimens, there were no significant differences in the expression of gut-homing markers, CCR9, and integrin α(4)ß(7). High-dose vitamin D(3) supplementation is needed to reverse vitamin D(3) deficiency in HIV-infected individuals and this results in modulation of skin-homing markers but not gut-homing markers expression on Treg. At a standard dose of 800 IU/day, vitamin D(3) is not effective in achieving an optimal 25(OH)D(3) concentration in patients with an underlying T cell dysfunction and is unable to exert any immunomodulatory effects.

CCL27-CCR10 and CXCL12-CXCR4 chemokine ligand-receptor mRNA expression ratio: new predictive factors of tumor progression in cutaneous malignant melanoma.

CXCR4, CCR7 and CCR10 chemokine receptors are known to be involved in melanoma metastasis. Our goal was to compare the relative intratumoral mRNA expression of these receptors with that of their corresponding chemokine ligands, CXCL12, CCL19, CCL21, and CCL27 across the full spectrum of human melanoma progression: thin and thick primary melanomas, as well as "in transit", lymph node, and distant metastases. Expression was quantified by real-time RT-PCR in 103 melanoma samples: 51 primary tumors and 52 metastases. Particular emphasis was focused on chemokine ligand-receptor expression ratios. Immunohistochemistry was performed to identify the cell types expressing these molecules. CXCL12-CXCR4 and CCL27-CCR10 ratios were higher in thin than in thick primary melanomas, and all four chemokine-receptor ratios were higher in primary tumors than in melanoma metastases. CCL27-CCR10 and CXCL12-CXCR4 expression ratios in primary tumors were inversely associated with the development of distant metastases, and improved the predictive value of tumor thickness for distant metastasis, which is important since chemokine ligand-receptor ratios are not affected by the endogenous gene employed for normalizing mRNA expression. Both receptor and ligand immunolabeling were detected in neoplastic cells suggesting autocrine mechanisms. Our results support the concept that low CCL27/CCR10 and CXCL12/CXCR4 intratumoral mRNA ratios are associated with melanoma progression, and in combination with Breslow thickness, are the best predictive factors for the development of distant metastases in primary cutaneous melanoma.

Overexpression of the chemokine receptors CXCR4, CCR7, CCR9, and CCR10 in human primary cutaneous melanoma: a potential prognostic value for CCR7 and CCR10?

Multiple functional implications have been suggested for a limited number of chemokines and their cognate receptors in melanoma pathogenesis. The purpose of this study was to investigate the potential role of the chemokine receptors CXCR4, CCR7, CCR9, and CCR10 as prognostic markers in human primary cutaneous melanoma. Chemokine receptor expression was analyzed by immunohistochemistry in a total of 38 patients with cutaneous melanoma. Results were statistically correlated with melanoma features and clinical disease progression. No significant correlation between overexpression of CXCR4 or CCR9 and survival or prognosis was found. CCR7 overexpression was associated with significantly lower survival (0.005 log rank) and shorter time to progression (0.009 log rank)-similar to CCR10 overexpression (lower survival: 0.001 log rank, shorter time to progression: 0.002 log rank). In addition, CCR7 overexpression correlated with expression of metallothionein, while CCR10 seems to be associated with cerebral metastases. Two chemokine receptors permitting the identification of high-risk patients were identified: CCR7 and CCR10 overexpressions were found to be associated with a worse outcome of disease course independent of Breslow's tumor thickness and Clark level, thus representing possible additional prognostic markers.

IL-17A induces CCL28, supporting the chemotaxis of IgE-secreting B cells.

BACKGROUND: Atopic asthma is an allergic disease typically associated with T(H)2 cytokines. IL-17A is also associated with asthma, through the induction of chemokines. Mucosal CCL28 concentrations correlate with cellular recruitment to inflamed airways and support migration of IgA(+) B cells. Here, a link between IL-17A, CCL28 and IgE-secreting B cell chemotaxis is examined. METHODS: Primary human airway cells and the airway epithelial line A549 were used to characterize IL-17A receptor expression and the effect of IL-17A on CCL28 transcription and translation. B cells, differentiated to IgE+ cells ex vivo, were assessed for CCR10 surface expression and chemotaxis to CCL28 by flow cytometry, transwell migration and ELISpot. RESULTS: Human airway epithelium expressed both IL-17RA and IL-17RC, and was responsive to IL-17A stimulation. Cultured human IgE+ B cells expressed surface CCR10 and displayed CCR10-dependent chemotaxis towards recombinant CCL28. Enhanced levels of CCL28 were observed upon A549 cell incubation with IL-17A, and this up-regulation significantly increased the migration of IgE+ antibody-secreting B cells. The specificity of chemotaxis was confirmed by migration blockade in the presence of anti-CCL28 or anti-CCR10. CONCLUSIONS: This work identifies a novel chemokine for the migration of IgE+ B cells, in addition to characterizing induction of CCL28 by IL-17A. Taken together the results presented here propose a new role for IL-17A in the allergic airways, linking this cytokine with the recruitment of IgE+ antibody-secreting B cells, via the induction of CCL28. These observations justify further in vivo studies of larger cohorts.

An investigation of the inflammatory cytokine and chemokine network in systemic sclerosis.

OBJECTIVES: Systemic sclerosis (SSc) is characterised by vasculopathy, an aberrantly activated immune system and excessive extracellular matrix deposition. Inflammatory chemokines control migration of cells to sites of tissue damage; their removal from inflamed sites is essential for resolution of the inflammatory response. The atypical chemokine receptor D6 has a critical role in this physiological balance. To explore potential deregulation of this system in SSc, inflammatory chemokine and D6 expression were compared with that in healthy controls (HC). METHODS: Serum levels of inflammatory mediators were assessed by luminex analysis. Peripheral blood mononuclear cells (PBMCs) were used in molecular and immunocytochemical analysis. Platelet-rich plasma was collected and assessed by western blotting for D6 expression levels. Sex-matched HC were used for comparison. RESULTS: 72 patients with SSc and 30 HC were enrolled in the study. The chemokines MCP-1/CCL2, MIP-1α/CCL3, MIP-1ß/CCL4 and IL-8/CXCL8 were significantly increased in patients with SSc, regardless of disease subtype and phase. Quantitative PCR analysis revealed a significant 10-fold upregulation of D6 transcripts in patients with SSc compared with controls, and this was paralleled by increased D6 protein expression in the PBMCs of patients with SSc. Platelet lysates also showed strong D6 expression in patients with SSc but not in controls. Importantly, high levels of D6 expression correlated with reduced levels of its ligands in serum. CONCLUSIONS: Inflammatory chemokines and the regulatory receptor D6 are significantly upregulated in SSc and high D6 levels are associated with lower systemic chemokine levels, indicating that some patients control systemic chemokine levels using D6. These results suggest that chemokines may represent a therapeutic target in SSc.

Coexpression of atypical chemokine binders (ACBs) in breast cancer predicts better outcomes.

Some evidence suggests that atypical chemokine binders (ACBs) including DARC, D6, and CCX-CKR play an important role in inhibiting invasion and metastasis of cancer cells; however, their expression in breast cancer has not been well characterized. The purpose of this study was to determine the predictive value of ACBs for relapse-free survival and overall survival in breast cancer. The expressions of the three molecules were analyzed immunohistochemically in a total of 558 consecutive breast specimens comprising 12 normal breast tissues, 29 noninvasive (carcinoma in situ), and 517 invasive breast carcinoma and their relationships to clinicopathological features and survival were investigated in invasive breast cancer. Coexpression of ACBs in invasive breast carcinoma (55.9%) was much lower that of noninvasive breast carcinoma (93.1%) and normal breast tissue (100.0%), P = 0.0004, 0.0096, respectively. Their separate stainings in invasive cancer were significantly conversely correlated with lymph node status and tumor stage. In univariate analysis, the three proteins and their coexpression were significantly associated with higher relapse-free survival and overall survival. In multivariate analysis, each of these molecules was favorable for relapse-free survival, but not overall survival. Surprisingly, their coexpression was not only independently prognostic factor for relapse-free survival (RR = 0.182, 95% CI: 0.101-0.327, P < 0.001), but also for overall survival (RR = 0.271, 95% CI: 0.081-0.910, P = 0.035). These findings highlight that the multiple loss of ACBs may occur during the development of tumorigenesis and their coexpression in breast cancer is predictive of favorable outcomes.

The vitamin D analog, TX527, promotes a human CD4+CD25highCD127low regulatory T cell profile and induces a migratory signature specific for homing to sites of inflammation.

The use of hypocalcemic vitamin D analogs is an appealing strategy to exploit the immunomodulatory actions of active vitamin D in vivo while circumventing its calcemic side effects. The functional modulation of dendritic cells by these molecules is regarded as the key mechanism underlying their ability to regulate T cell reactivity. In this article, we demonstrate the capacity of the vitamin D analog, TX527, to target T cells directly. Microarray analysis of purified human CD3(+) T cells, cultured in the presence of TX527, revealed differential expression of genes involved in T cell activation, proliferation, differentiation, and migratory capacity. Accordingly, functional analysis showed a TX527-mediated suppression of the T cell proliferative capacity and activation status, accompanied by decreased expression of effector cytokines (IFN-γ, IL-4, and IL-17). Furthermore, TX527 triggered the emergence of CD4(+)CD25(high)CD127(low) regulatory T cells featuring elevated levels of IL-10, CTLA-4, and OX40 and the functional capacity to suppress activation and proliferation of effector T cells. Moreover, the vitamin D analog profoundly altered the homing receptor profile of T cells and their migration toward chemokine ligands. Remarkably, TX527 not only modulated skin-homing receptors as illustrated for the parent compound, but also reduced the expression of lymphoid organ-homing receptors (CD62L, CCR7, and CXCR4) and uniquely promoted surface expression of inflammatory homing receptors (CCR5, CXCR3, and CXCR6) on T cells. We conclude that TX527 directly affects human T cell function, thereby inhibiting effector T cell reactivity while inducing regulatory T cell characteristics, and imprints them with a specific homing signature favoring migration to sites of inflammation.

Polymeric IgA-secreting and mucosal homing pre-plasma cells in normal human peripheral blood.

Clear identification of recently activated mucosal B cells in human blood would greatly facilitate study of mucosal vaccines, immune response to infection and the ongoing mucosal IgA response. We examined blood lymphocytes from normal, healthy individuals to identify IgA-secreting pre-plasma cells' (PPC) functional and phenotypic relevance to mucosal antibody production, in the absence of infection, disease or recent vaccination. PPC are the most recently activated B lymphocytes in blood and are considered in transit between lymphoid tissue and effector tissues, where they terminally differentiate into plasma cells. We observed that all IgA-secreting PPC expressed surface IgA (sIgA) and intracellular IgA (icIgA) and secreted primarily polymeric IgA (pIgA), as determined by flow cytometry, ELISPOT and size exclusion chromatography. A large sub-population of PPC in blood expresses the mucosal chemokine receptor CCR10 and contains the largest fraction of sIgA and icIgA PPC that secrete pIgA. The majority of CCR10(+) PPC expresses high levels of Ki67, indicative of recently activated blasts. In contrast, most CCR10(-) PPC secrete IgG, but a small population secretes pIgA and stains for icIgA. The mucosal integrin alpha(4)beta(7) was detected on a subset of PPC, but this subset did not account for all CCR10(+) PPC or all PPC with sIgA expression. Our data clearly demonstrate that PPC defined by surface expression of CD19, CD27(hi), IgA and CCR10 secrete only pIgA and are the dominant mucosal PPC subset in human blood. These mucosal PPC can now be investigated routinely as indicators of recent human mucosal IgA responses.

Chemokine scavenger D6 is expressed by trophoblasts and aids the survival of mouse embryos transferred into allogeneic recipients.

Proinflammatory CC chemokines are thought to drive recruitment of maternal leukocytes into gestational tissues and regulate extravillous trophoblast migration. The atypical chemokine receptor D6 binds many of these chemokines and is highly expressed by the human placenta. D6 is thought to act as a chemokine scavenger because, when ectopically expressed in cell lines in vitro, it efficiently internalizes proinflammatory CC chemokines and targets them for destruction in the absence of detectable chemokine-induced signaling. Moreover, D6 suppresses inflammation in many mouse tissues, and notably, D6-deficient fetuses in D6-deficient female mice show increased susceptibility to inflammation-driven resorption. In this paper, we report strong anti-D6 immunoreactivity, with specific intracellular distribution patterns, in trophoblast-derived cells in human placenta, decidua, and gestational membranes throughout pregnancy and in trophoblast disease states of hydatidiform mole and choriocarcinoma. We show, for the first time, that endogenous D6 in a human choriocarcinoma-derived cell line can mediate progressive chemokine scavenging and that the D6 ligand CCL2 can specifically associate with human syncytiotrophoblasts in term placenta in situ. Moreover, despite strong chemokine production by gestational tissues, levels of D6-binding chemokines in maternal plasma decrease during pregnancy, even in women with pre-eclampsia, a disease associated with increased maternal inflammation. In mice, D6 is not required for syngeneic or semiallogeneic fetal survival in unchallenged mice, but interestingly, it does suppress fetal resorption after embryo transfer into fully allogeneic recipients. These data support the view that trophoblast D6 scavenges maternal chemokines at the fetomaternal interface and that, in some circumstances, this can help to ensure fetal survival.

Identification of a human helper T cell population that has abundant production of interleukin 22 and is distinct from T(H)-17, T(H)1 and T(H)2 cells.

Interleukin 22 (IL-22) is a member of the IL-10 cytokine family that is involved in inflammatory and wound healing processes. Originally considered a T helper type 1 (T(H)1)-associated cytokine, IL-22 has since been shown to be produced mainly by IL-17-producing helper T cells (T(H)-17 cells). Here we describe a previously uncharacterized IL-22-producing human helper T cell population that coexpressed the chemokine receptor CCR6 and the skin-homing receptors CCR4 and CCR10. These cells were distinct from both T(H)-17 cells and T(H)1 cells. Downregulation of either the aryl hydrocarbon receptor (AHR) or the transcription factor RORC by RNA-mediated interference affected IL-22 production, whereas IL-17 production was affected only by downregulation of RORC by RNA-mediated interference. AHR agonists substantially altered the balance of IL-22- versus IL-17-producing cells. This subset of IL-22-producing cells may be important in skin homeostasis and pathology.

Hemopoietic cell expression of the chemokine decoy receptor D6 is dynamic and regulated by GATA1.

D6 scavenges inflammatory chemokines and is essential for the regulation of inflammatory and immune responses. Mechanisms explaining the cellular basis for D6 function have been based on D6 expression by lymphatic endothelial cells. In this study, we demonstrate that functional D6 is also expressed by murine and human hemopoietic cells and that this expression can be regulated by pro- and anti-inflammatory agents. D6 expression was highest in B cells and dendritic cells (DCs). In myeloid cells, LPS down-regulated expression, while TGF-beta up-regulated expression. Activation of T cells with anti-CD3 and soluble CD28 up-regulated mRNA expression 20-fold, while maturation of human macrophage and megakaryocyte precursors also up-regulated D6 expression. Competition assays demonstrated that chemokine uptake was D6 dependent in human leukocytes, whereas mouse D6-null cells failed to uptake and clear inflammatory chemokines. Furthermore, we present evidence indicating that D6 expression is GATA1 dependent, thus explaining D6 expression in myeloid progenitor cells, mast cells, megakaryocytes, and DCs. We propose a model for D6 function in which leukocytes, within inflamed sites, activate D6 expression and thus trigger resolution of inflammatory responses. Our data on D6 expression by circulating DCs and B cells also suggest alternative roles for D6, perhaps in the coordination of innate and adaptive immune responses. These data therefore alter our models of in vivo D6 function and suggest possible discrete, and novel, roles for D6 on lymphatic endothelial cells and leukocytes.

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.

1,25-dihydroxyvitamin D3 induces CCR10 expression in terminally differentiating human B cells.

In the B cell lineage, CCR10 is known to be selectively expressed by plasma cells, especially those secreting IgA. In this study, we examined the regulation of CCR10 expression in terminally differentiating human B cells. As reported previously, IL-21 efficiently induced the differentiation of activated human CD19+ B cells into IgD-CD38+ plasma cells in vitro. A minor proportion of the resulting CD19+IgD-CD38+ cells expressed CCR10 at low levels. 1,25-Dihydroxyvitamin D3 (1,25-(OH)2D3), the active metabolite of vitamine D3, dramatically increased the proportion of CD19+IgD-CD38+ cells expressing high levels of CCR10. The 1,25-(OH)2D3 also increased the number of CCR10+ cells expressing surface IgA, although the majority of CCR10+ cells remained negative for surface IgA. Thus, 1,25-(OH)2D3 alone may not be sufficient for the induction of IgA expression in terminally differentiating human B cells. To further determine whether 1,25-(OH)2D3 directly induces CCR10 expression in terminally differentiating B cells, we next performed the analysis on the human CCR10 promoter. We identified a proximal Ets-1 site and an upstream potential vitamin D response element to be critical for the inducible expression of CCR10 by 1,25-(OH)2D3. We confirmed the specific binding of Ets-1 and 1,25-(OH)2D3-activated vitamin D receptor to the respective sites. In conclusion, 1,25-(OH)2D3 efficiently induces CCR10 expression in terminally differentiating human B cells in vitro. Furthermore, the human CCR10 promoter is cooperatively activated by Ets-1 and vitamin D receptor in the presence of 1,25-(OH)2D3.

The mucosae-associated epithelial chemokine (MEC/CCL28) modulates immunity in HIV infection.

BACKGROUND: CCL28 (MEC) binds to CCR3 and CCR10 and recruits IgA-secreting plasma cells (IgA-ASC) in the mucosal lamina propria (MLP). Mucosal HIV-specific IgA are detected in HIV-infection and exposure. The CCL28 circuit was analyzed in HIV-infected and-exposed individuals and in HIV-unexposed controls; the effect of CCL28 administration on gastrointestinal MLP IgA-ASC was verified in a mouse model. METHODOLOGY/FINDINGS: CCL28 was augmented in breast milk (BM) plasma and saliva of HIV-infected and -exposed individuals; CCR3+ and CCR10+ B lymphocytes were increased in these same individuals. Additionally: 1) CCL28 concentration in BM was associated with longer survival in HIV vertically-infected children; and 2) gastro-intestinal mucosal IgA-ASC were significantly increased in VSV-immunized mice receiving CCL28. CONCLUSIONS: CCL28 mediates mucosal immunity in HIV exposure and infection. CCL28-including constructs should be considered in mucosal vaccines to prevent HIV infection of the gastro-intestinal MLP via modulation of IgA-ASC.

Inflammation of the respiratory tract is associated with CCL28 and CCR10 expression in a murine model of allergic asthma.

Mouse models and in vitro cell culture were used to examine airway expression of the mucosal chemokine CCL28. Low levels of constitutively expressed mRNA were observed in transformed murine epithelial cells, but high levels could be induced by stimulation. Cytokines that signal through NF-kappaB, including IL-1beta and TNF-alpha or via JAK-STAT pathway including oncostatin M induced CCL28 in airway epithelial cells in vitro. Immunohistochemistry of murine airway tissue revealed that constitutive expression of CCL28 protein in vivo was low and not ubiquitous. However, abundant expression was detected in epithelia and lymphoid aggregates following allergic sensitization and challenge with ovalbumin. This was accompanied by increased detection of cells expressing CCR10 protein and mRNA in inflamed airways. Taken together, these data support a role for CCL28 in contributing to allergen driven airway pathologies, show that proinflammatory cytokines can induce this signal and suggest a role for CCR10 expressing cells in airway inflammation.