Over-expression of Nav1.6 channels is associated with lymph node metastases in colorectal cancer.

BACKGROUND AND OBJECTIVES: Lymph node metastasis is a key factor in predicting and determining the prognosis of patients with colorectal cancer (CRC). Sodium channels are highly expressed in a variety of tumors and are closely related to tumor development, metastasis, and invasion. We investigated the relationship between the expressions of different subtypes of Nav channels and lymph node metastasis of CRC. METHODS: Real-time PCR (RT-qPCR) was carried out to measure the expressions of different sodium channel subtypes, chemokine receptors (CCR2, CCR4, CCR7), and lymphocyte infiltration-related biomarkers (CD3e, CD8a, IL-2RA) in CRC tissues from 97 patients. The expressions of Nav1.5 and Nav1.6 in surgically isolated lymph nodes were detected by immunohistochemistry. Correlation analysis between expressions of different genes and lymph node metastasis was performed by two-tailed t test. RESULTS: Nav1.1 and Nav1.6 were highly expressed in CRC tissues and positively correlated with CRC lymph node metastasis. Nav1.6 was also highly expressed in metastatic lymph nodes. Further analysis showed that the high expression of Nav1.6 was closely related to the one of CCR2\CCR4 in tumor lymph node metastasis. CONCLUSIONS: These results suggested that Nav1.6 might be a novel marker for CRC lymph node metastasis.

Increased infiltration of CCR4-positive regulatory T cells in prostate cancer tissue is associated with a poor prognosis.

BACKGROUND: Regulatory T cells (Tregs) play important roles in the suppression of immune responses, including antitumor immune responses. C-C chemokine receptor 4 (CCR4) is highly expressed on effector Tregs, and anti-CCR4 antibody is attracting attention as a novel immunotherapeutic agent for solid tumors. This study aimed to evaluate the expression of CCR4-positive Tregs (CCR4+Tregs) in prostate cancer and estimate the clinical potential of CCR4-targeting therapy for prostate cancer. METHODS: A total of 15 radical prostatectomy (RP) specimens and 60 biopsy specimens from individuals diagnosed with prostate cancer were analyzed to evaluate the infiltration of CCR4+Tregs in prostate cancer. The relationships between the number of CCR4+Tregs and clinical parameters were investigated in RP and biopsy specimens. Moreover, the total number of Tregs, CCR4+Tregs, and T cells and the ratio of CCR4+Tregs to Tregs and T cells in biopsy specimens were compared between patients with poor prognosis who progressed to castration-resistant prostate cancer (CRPC) within 12 months (n = 13) and those with good prognosis who were stable with hormone-sensitive prostate cancer over 12 months (n = 47). Furthermore, biopsy specimens were divided into two groups: low and high CCR4+Treg expression groups and the prognosis was compared between them. RESULTS: There was a higher expression of CCR4+Tregs in RP specimens with a higher (≥8) Gleason score than in those with a lower (<8) Gleason score (P = .041). In biopsy specimens, 65.9% Tregs were positive for CCR4. The number of CCR4+Tregs positively correlated with clinical stage (P < .001) and Gleason score (P = .006). The total number of Tregs and CCR4+Tregs significantly increased in the poor prognosis group compared with that in the good prognosis group (P = .024 and .01, respectively). Furthermore, patients with lower CCR4+Treg expression levels showed a significantly longer time to progression to CRPC (not reached vs 27.3 months; P < .001) and median survival time (not reached vs 69.0 months; P = .014) than those with higher expression levels. CONCLUSIONS: CCR4+Tregs are highly infiltrated in the prostate tissue of patients with poor prognosis with potential to progress to CRPC. Furthermore, the degree of infiltration of CCR4+Tregs is related to the prognosis of prostate cancer.

Expression of CCR3 and CCR4 Suggests a Poor Prognosis in Mycosis Fungoides and Sézary Syndrome.

Tumor cells in cutaneous T-cell lymphoma express limited numbers of chemokine receptors. We investigated the expression patterns of CXCR3, CCR3, CCR4 and CCR10 in mycosis fungoides, Sézary syndrome, lym-phomatoid papulosis and anaplastic large cell lymphoma in 121 skin biopsy samples. CXCR3 was expressed in 86% of mycosis fungoides cases but in no anaplastic large cell lymphoma cases. CCR3 was expressed in 73% of cases of CD30+ lymphoproliferative disorders such as lymphomatoid papulosis and anaplastic large cell lymphoma. Mycosis fungoides/Sézary syndrome patients with high CCR3 or CCR4 expression had a poorer survival prognosis than mycosis fungoides/Sézary syndrome patients whose tumor cells did not express these receptors. CCR10 was expressed in 50% of mycosis fungoides/Sézary syndrome cases and in 13% of cases with CD30+ lym-phoproliferative disorders. These results suggest that differential patterns of CXCR3, CCR3, CCR4 and CCR10 expression are useful for the diagnosis of cutaneous T-cell lymphoma. Moreover, expression of CCR3 or CCR4 suggests a poor prognosis in mycosis fungoides/Sézary syndrome.

Gaucheromas: When macrophages promote tumor formation and dissemination.

Deficiency of the lysosomal enzyme, ß-glucocerebrosidase, and accumulation of its substrate in cells of the reticuloendothelial system affects multiple organ systems in patients with Gaucher disease (GD). Lipid laden macrophages turn into Gaucher cells (GC) which are the pathological characteristic of GD. GC focally accumulate in the liver, spleen and at extraosseous sites to form benign lesions called Gaucheromas. Gaucheromas pose diagnostic and therapeutic challenges. We studied the pathophysiology of extraosseous Gaucheroma formation in a cohort of patients with GD. Among 63 patients followed at a single center, 3 patients with genotypes L444P/L444P and N370S/N370S, were diagnosed with extraosseous Gaucheromas. Flow cytometry revealed a higher expression of CD16+/CCR4+ non-classical monocytes in blood of GD patients who have developed Gaucheromas. A biopsy showed infiltration of GC, which reactivity against CD163, CD68 and VEGF. The cell proliferative marker Ki67 and CCL2, a factor anti-tumor activity, were negative. Our study indicates that extraosseous Gaucheromas are comprised of cellular elements with characteristics of tumor-associated macrophages, the major players in cancer related inflammation. The occurrence of non-classical CD16+/CCR4+ monocytes reflect the underlying cause for the accumulation of the macrophages capable of migrating to distant sites outside the reticuloendotheial system, and giving rise to tumor-like Gaucheromas.

T cells are involved in the induction of macrophage phenotypes in oral leukoplakia and squamous cell carcinoma-a preliminary report.

BACKGROUND: The prognosis of human malignancies has been shown to depend on immunological parameters, such as macrophage polarization (M1 and M2). In this study, we identify the phenotype of macrophages, and investigate an involvement of infiltrated T cells that participate in the polarization of macrophages, in oral leukoplakia (OLK), and oral squamous cell carcinoma (OSCC). METHODS: Immunohistochemical method was used to examine the number of CD68+ , CD163+ (M2), iNOS+ (M1) macrophages, and CD4+ , CD8+ , CCR4+ (Th2), CCR5+ (Th1) cells in 102 cases of OSCC: without metastases-OSCC M(-) (n = 54), and with metastases-OSCC M(+) (n = 48), 23 cases of OLK, and 18 control cases. RESULTS: The mean number of CD68+ , CD163+ , iNOS+ , CD4+ , CCR4+ , CCR5+ cells was significantly increased in OSCC M(+) group compared with OLK, OSCC M(-) and control group. We found positive correlations between the number of CD4+ T cells and CD163+ and iNOS+ macrophages as well as CCR4+ and CCR5+ cells in both OSCC groups. The mean number of CD8+ cells was significantly increased in OSCC M(-) and OLK compared with OSCC M(+) and control group. In OSCC M(+) and OSCC M(-) groups, a negative correlation between the number of CD8+ cells and CD163+ and iNOS+ macrophages was found. CONCLUSIONS: The number and co-localization of lymphocytes and macrophages in OLK and OSCC may indicate that infiltrating cells influence the early and subsequent stage of oral carcinogenesis.

An expanded population of pathogenic regulatory T cells in giant cell arteritis is abrogated by IL-6 blockade therapy.

OBJECTIVES: Randomised-controlled trials have recently proven the efficacy of the interleukin (IL)-6 receptor antagonist tocilizumab (TCZ) in giant cell arteritis (GCA). However, the mechanism of action of IL-6 blockade in this disease is unknown. Moreover, the role of regulatory T (Treg) cells in the pathogenesis of GCA remains underexplored. Given the plasticity of Tregs and the importance of IL-6 in their biology, we hypothesised that TCZ might modulate the Treg response in GCA. We therefore characterised the Treg compartment of patients with GCA treated with TCZ. METHODS: We classified 41 patients with GCA into three groups: active disease (aGCA, n=11), disease remission on corticosteroids (rGCA-CS, n=19) and disease remission on TCZ (rGCA-TCZ, n=11). Healthy controls (HCs) were included for comparison. We determined the frequency, phenotype and function of peripheral blood Tregs. RESULTS: Patients with aGCA demonstrated a hypoproliferating Treg compartment enriched in IL-17-secreting Tregs (IL-17+Tregs). Tregs in patients with aGCA disproportionally expressed a hypofunctional isoform of Foxp3 that lacks exon 2 (Foxp3Δ2). Foxp3Δ2-expressing Tregs coexpressed CD161, a marker commonly associated with the Th17 linage, significantly more often than full-length Foxp3-expressing Tregs. Compared with those of HCs, GCA-derived Tregs demonstrated impaired suppressor capacity. Treatment with TCZ, in contrast to CS therapy, corrected the Treg abnormalities observed in aGCA. In addition, TCZ treatment increased the numbers of activated Tregs (CD45RA-Foxp3high) and the Treg expression of markers of trafficking (CCR4) and terminal differentiation (CTLA-4). CONCLUSIONS: TCZ may exert its therapeutic effects in GCA by increasing the proliferation and activation of Tregs, and by reverting the pathogenic Treg phenotype seen during active disease.

Characteristics of peripheral blood CD4+CD25+ regulatory T cells and related cytokines in severe atopic dermatitis.

Regulatory T cells (Tregs) have been suggested to play a role in the pathogenesis of atopic dermatitis (AD). However, alterations in the ability of Tregs remain to be determined. To investigate the expression of various surface receptors on CD4(+)CD25(high) regulatory T cells and to investigate their capacity for inhibiting the proliferation of CD4(+) CD25(-) effector T cells (Teffs). Peripheral blood samples were obtained from 15 patients with severe atopic dermatitis (AD) and 20 control subjects. FACs was then carried out to analyze the expression levels of FoxP3, CD152 (CTLA-4), CD39, CD73, CD223 (LAG-3), CCR4, CCR5, and CCR10 on Tregs. The proliferative responses of Teffs were assessed in the absence or presence of autologous Tregs and the TGF-ß1 and IL-10 levels in the culture supernatant and sera were detected by enzyme-linked immunosorbent assay (ELISA). The CD152, CD39, CD73, CCR4, and CCR5 expression levels on Tregs were higher in patients with severe AD than in the controls. Tregs showed an attenuated suppressive function of the proliferation of autologous Teffs in severe AD. The concentrations of IL-10 and TGF-ß in the culture supernatants of Tregs were lower in the AD group than in the control. The attenuated ability of Tregs to suppress Teff proliferation may be responsible for the autoimmune reaction of severe AD.

CCR4 frameshift mutation identifies a distinct group of adult T cell leukaemia/lymphoma with poor prognosis.

Adult T cell leukaemia/lymphoma (ATLL) is an intractable T cell neoplasm caused by human T cell leukaemia virus type 1. Next-generation sequencing-based comprehensive mutation studies have revealed recurrent somatic CCR4 mutations in ATLL, although clinicopathological findings associated with CCR4 mutations remain to be delineated. In the current study, 184 cases of peripheral T cell lymphoma, including 113 cases of ATLL, were subjected to CCR4 mutation analysis. This sequence analysis identified mutations in 27% (30/113) of cases of ATLL and 9% (4/44) of cases of peripheral T cell lymphoma not otherwise specified. Identified mutations included nonsense (NS) and frameshift (FS) mutations. No significant differences in clinicopathological findings were observed between ATLL cases stratified by presence of CCR4 mutation. All ATLL cases with CCR4 mutations exhibited cell-surface CCR4 positivity. Semi-quantitative CCR4 protein analysis of immunohistochemical sections revealed higher CCR4 expression in cases with NS mutations of CCR4 than in cases with wild-type (WT) CCR4. Furthermore, among ATLL cases, FS mutation was significantly associated with a poor prognosis, compared with NS mutation and WT CCR4. These results suggest that CCR4 mutation is an important determinant of the clinical course in ATLL cases, and that NS and FS mutations of CCR4 behave differently with respect to ATLL pathophysiology.

Compartment-specific immunity in the human gut: properties and functions of dendritic cells in the colon versus the ileum.

OBJECTIVE: Dendritic cells (DC) mediate intestinal immune tolerance. Despite striking differences between the colon and the ileum both in function and bacterial load, few studies distinguish between properties of immune cells in these compartments. Furthermore, information of gut DC in humans is scarce. We aimed to characterise human colonic versus ileal DC. DESIGN: Human DC from paired colonic and ileal samples were characterised by flow cytometry, electron microscopy or used to stimulate T cell responses in a mixed leucocyte reaction. RESULTS: A lower proportion of colonic DC produced pro-inflammatory cytokines (tumour necrosis factor-α and interleukin (IL)-1ß) compared with their ileal counterparts and exhibited an enhanced ability to generate CD4(+)FoxP3(+)IL-10(+) (regulatory) T cells. There were enhanced proportions of CD103(+)Sirpα(-) DC in the colon, with increased proportions of CD103(+)Sirpα(+) DC in the ileum. A greater proportion of colonic DC subsets analysed expressed the lymph-node-homing marker CCR7, alongside enhanced endocytic capacity, which was most striking in CD103(+)Sirpα(+) DC. Expression of the inhibitory receptor ILT3 was enhanced on colonic DC. Interestingly, endocytic capacity was associated with CD103(+) DC, in particular CD103(+)Sirpα(+) DC. However, expression of ILT3 was associated with CD103(-) DC. Colonic and ileal DC differentially expressed skin-homing marker CCR4 and small-bowel-homing marker CCR9, respectively, and this corresponded to their ability to imprint these homing markers on T cells. CONCLUSIONS: The regulatory properties of colonic DC may represent an evolutionary adaptation to the greater bacterial load in the colon. The colon and the ileum should be regarded as separate entities, each comprising DC with distinct roles in mucosal immunity and imprinting.

CCR4 is expressed on infiltrating cells in lesional skin of early mycosis fungoides and atopic dermatitis.

CCR4 is expressed on tumor cells of mycosis fungoides (MF) and Sézary syndrome (SS). In MF, most infiltrating cells in patches and plaques express CXCR3, while tumor cells express CCR4 in advanced stages. Poteligeo Test IHC (CCR4 staining kit) is a newly developed staining kit that can examine the presence of CCR4 expressed on tumor cells of adult T-cell leukemia/lymphoma, peripheral T-cell lymphoma and cutaneous T-cell lymphoma before treatment of anti-CCR4 antibody using paraffin-embedded samples. In this study, we analyzed CCR4 expression in lesional skin of MF, SS, atopic dermatitis (AD) and psoriasis with this new kit. CCR4 was expressed on infiltrating cells in lesional skin of patch, plaque, tumor MF and SS, and the number of positive cells increased as the disease progressed. Immunohistochemistry with frozen sections also showed some positive cells scattered in the dermis, although the quality was not high enough to quantify positive cells. There were significant positive correlations between CCR4(+) cells and serum lactate dehydrogenase levels. Interestingly, CCR4(+) cells were also detected in AD skin, whose number was larger than that in psoriatic skin. Previous studies showed only scattered CCR4(+) cells in skin samples by standard immunohistochemical staining. The new, sensitive CCR4 staining kit has revealed that CCR4 is expressed on infiltrating cells in lesional skin of early MF and AD as well as advanced MF and SS. These cells can be therapeutic targets for patients who are resistant to standard treatments.

TOX expression in different subtypes of cutaneous lymphoma.

Early cutaneous T cell lymphoma clinically and histologically resembles benign inflammatory skin diseases, which sometimes makes it difficult to reach a correct diagnosis. It is recently reported that thymocyte selection-associated high mobility group box factor (TOX) serves as a molecular marker for histological diagnosis of early-stage mycosis fungoides (MF). To examine whether TOX could be a marker of tumour cells in different types of cutaneous lymphoma, we investigated immunohistochemical staining for TOX with the lesional skin of patch, plaque, and tumour MF, Sézary syndrome (SS), lymphomatoid papulosis (LyP), primary cutaneous anaplastic large cell lymphoma (PCALCL), adult T cell leukemia/lymphoma (ATLL), peripheral T-cell lymphoma, not otherwise specified (PTCL, NOS), atopic dermatitis (AD), and normal skin. TOX and CCR4 messenger RNA (mRNA) levels in lesional skin of MF/SS were also examined. Immunohistological staining showed that a high specific nuclear staining of TOX was observed at a high frequency in MF, SS, and PTCL, NOS. Tumour cells in LyP, PCALCL, and ATLL showed a slightly dim nuclear staining of TOX. TOX(+) cells in MF and LyP expressed surface molecules characteristics of tumour cells in these diseases. Lesional skin of SS expressed higher levels of TOX mRNA, compared to normal skin or MF lesional skin. Moreover, TOX expression significantly correlated with CCR4 expression. TOX may be a specific marker for tumour cells in some types of cutaneous lymphoma.

Invariant natural killer T cells are enriched at the site of cutaneous inflammation in lupus erythematosus.

BACKGROUND: Systemic lupus erythematosus (SLE) is associated with a numerical and functional reduction of peripheral blood (PB) invariant natural killer T (iNKT) cells. Limited information exists on the role of iNKT cells in the pathogenesis of lupus erythematosus. OBJECTIVE: To investigate the frequency and phenotype of iNKT cells in PB and dermal infiltrates from patients with SLE, subacute-cutaneous lupus erythematosus (SCLE) and discoid lupus erythematosus (DLE). METHODS: PB was obtained from 23 SLE, 6 SCLE, and 11 DLE patients, and from 30 healthy controls. iNKT cell frequency and CCR4/CCR6 surface expression were assessed by flow cytometry. The frequency and phenotype of skin infiltrating Vα24(+)Vß11(+) iNKT cells were investigated by immunofluorescence in lesional biopsies from 20 patients, unaffected skin from 3 patients, and from 6 healthy controls. RESULTS: Lupus erythematosus patients displayed significantly lower percentages of circulating CD3(+)6B11(+) iNKT cells compared to healthy controls. Whereas CCR6 expression on iNKT cells was enhanced in active SLE patients regardless of cutaneous involvement compared to healthy controls, CCR4 was exclusively increased in patients with active cutaneous lesions. Furthermore, iNKT cells were significantly enriched in lesional skin of SLE and DLE patients, but not in unaffected skin of lupus patients. The majority of lesional iNKT cells expressed IFN-γ and CCR4. CONCLUSION: The deficiency in circulating iNKT cells in cutaneous lupus erythematosus is associated with an increase of iNKT cells at the site of cutaneous inflammation. These data underscore the importance of analyzing iNKT cells not only in PB, but also in the target tissues.

Ratio of T helper to regulatory T cells in synovial fluid and postoperative joint laxity after allograft anterior cruciate ligament reconstruction.

BACKGROUND: Arthroscopic anterior cruciate ligament (ACL) reconstruction with allograft may vary in instrumented laxity compared with autograft. T helper (Th) cells (CCR4+CCR6+Th) and regulatory T (Treg) cells are important in the early stage of immunologic reactions. It is unknown whether the ratio of CCR4+CCR6+Th to Treg is imbalanced and if it correlates with early postoperative laxity after ACL allograft reconstruction. We investigated the ratio and functional influence between these cells and the correlation with postoperative anterior knee laxity. METHODS: In 40 patients who experienced unilateral arthroscopy-assisted ACL reconstruction, the ACL graft was an allograft in 20 patients and autograft in 20 patients. Maximum manual anterior tibiofemoral laxity measurements were performed with arthrometry testing. The phenotypes of CCR4+CCR6+Th and Treg cells of peripheral blood and synovial fluid from the two patient groups were determined by flow cytometry. The functionality of isolated Treg cells and effector T cells was quantified in (3)H-thymidine proliferation assays. RESULTS: Both CCR4+CCR6+Th and Treg cells were significantly increased in the synovial fluid in the allograft group and were correlated with anterior knee laxity. The ratio of CCR4+CCR6+Th to Treg cells in the synovial fluid was positively correlated with laxity. Synovial CD4+CD25+ Treg cells displayed an increased suppressive capacity compared with blood CD4+CD25+ Treg cells. Activated responder T cells from the synovial fluid were less susceptible to CD4+CD25+ T cell-mediated suppression than were responder cells from blood. CONCLUSIONS: The ratio of CCR4+CCR6+Th to Treg cells in the synovial fluid was correlated with anterior laxity after ACL allograft reconstruction.

Cytokine/chemokine profiles contribute to understanding the pathogenesis and diagnosis of primary Sjögren's syndrome.

To investigate the pathogenesis of localized autoimmune damage in Sjögren's syndrome (SS) by examining the expression patterns of cytokines, chemokines and chemokine receptors at sites of autoimmune damage. mRNA expression of these molecules in the labial salivary glands (LSGs) and peripheral blood mononuclear cells (PBMCs) from 36 SS patients was examined using a real-time polymerase chain reaction-based method. Subsets of the infiltrating lymphocytes and chemokines/chemokine receptors expression in the LSG specimens were examined by immunohistochemistry. Cytokines/chemokine concentrations in the saliva were analysed using flow cytometry or enzyme-linked immunosorbent assay. mRNA expression of T helper type 1 (Th1) cytokines, chemokines and chemokine receptors was higher in LSGs than in PBMCs. In contrast, mRNA expression of Th2 cytokines, chemokines [thymus and activation-regulated chemokine (TARC/CCL17), macrophage-derived chemokine (MDC/CCL22)] and chemokine receptor (CCR4) was associated closely with strong lymphocytic accumulation in LSGs. Furthermore, TARC and MDC were detected immunohistochemically in/around the ductal epithelial cells in LSGs, whereas CCR4 was detected on infiltrating lymphocytes. The concentrations of these cytokines/chemokines were significantly higher in the saliva from SS patients than those from controls, and the concentrations of Th2 cytokines/chemokines were associated closely with strong lymphocytic accumulation in LSGs. These results suggest that SS might be initiated and/or maintained by Th1 and Th17 cells and progress in association with Th2 cells via the interaction between particular chemokines/chemokine receptors. Furthermore, the measurement of cytokines/chemokines in saliva is suggested to be useful for diagnosis and also to reveal disease status.

Immune profile and Epstein-Barr virus infection in acute interstitial nephritis: an immunohistochemical study in 78 patients.

BACKGROUND: Acute interstitial nephritis (AIN) is a common cause of acute kidney injury and is characterised by a dense interstitial cellular infiltrate, which has not been well defined. Previous studies have demonstrated a correlation between Epstein-Barr virus (EBV) infection and AIN. The purpose of our study was to define the nature of the interstitial immune infiltrate and to investigate the possibility of renal infection with EBV. METHODS: Seventy-eight patients with AIN were identified from renal biopsy reports in a single centre over an 18-year period. Immunohistochemical staining was performed to define the cellular infiltrate. In situ hybridization and immunohistology were used to detect EBV. RESULTS: A positive correlation between CD68 macrophage infiltration and serum creatinine concentration at presentation was identified. IL-4, eotaxin, CCR3, CCR5 and VCAM-1 were all expressed in biopsies of AIN. Using in situ hybridization and immunohistochemistry, EBV was not detected in any of the AIN sections analysed. CONCLUSION: This study has assessed the nature of the interstitial infiltrate in AIN. EBV was not detected in the renal biopsies, suggesting that EBV is not a pathogenetic factor in AIN.

Aberrant expression of chemokine receptor CCR4 in human gastric cancer contributes to tumor-induced immunosuppression.

The chemokine receptor CCR4 is preferentially expressed on certain immune cells and some hematological tumor cells, which play pivotal roles in suppression of host immune response. However, the reasons for the upmodulation of CCR4 and its immune functions in solid tumors remain unclear. Herein, we aimed to determine the expression profiles of CCR4 in gastric cancer cells and its role in regulating antitumor immunity. CCR4 expression was assessed in 63 cases of gastric carcinomas by immunohistochemistry. We found cancer cells in lymphocyte-rich carcinomas more frequently showed moderate to strong positive staining for CCR4 than those in conventional carcinomas (P = 0.041), and also found a positive relationship between expression of CCR4 and tumor necrosis factor-α (P = 0.012). Stimulation of gastric cell lines with various cytokines showed that tumor necrosis factor-α uniquely upmodulated CCR4 expression through activation of nuclear factor-κB. Additional coculture experiments showed the forced expression of CCR4 in SGC-7901 cells caused a significant reduction of γ-interferon and elevation of interleukin-10 secretion in the supernatants from cocultured SGC-7901 cells and PBMCs. In addition, granzyme A production in cancer cell-cocultured CD56(+) natural killer cells was significantly downregulated. Inhibition of the overexpressed CCR4 in cancer cells by an inhibitor of CCR4, compound 39, proved to partly restore the antitumor immunity in respect of the inverse changes in those factors. Our studies suggest that the aberrant expression of CCR4 in human gastric cancer could contribute to tumor-induced immunosuppression. Conceivably, downmodulation of CCR4 expression could be a promising immunotherapy for human gastric cancer.

Adipose derived stem cells (ASCs) isolated from breast cancer tissue express IL-4, IL-10 and TGF-ß1 and upregulate expression of regulatory molecules on T cells: do they protect breast cancer cells from the immune response?

Immunomodulatory function of bone marrow derived mesenchymal stem cells in cancer has recently been investigated. But the resident mesenchymal stem cells as whole in cancer and in the breast cancer tissue have not been studied well. In the present work we isolated adipose derived stem cells (ASCs) from breast cancer and normal breast tissues to investigate the expressions of IL-4, IL-10 and transforming growth factor (TGF)-ß1 in ASCs and to see if ASCs isolated from patients can modulate the regulatory molecules on peripheral blood lymphocytes. Our results showed that IL-10 and TGF-ß1 have significantly higher mRNA expressions in ASCs isolated from breast cancer patients than those from normal individuals (P value <0.05). The culture supernatant of ASCs isolated from breast cancer patients with pathological stage III induced upregulation of the mRNA expression levels of IL-4, TGF-ß1, IL-10, CCR4 and CD25 in PBLs. In addition, the percentage of CD4+CD25(high)Foxp3(+) T regulatory cells was increased in vitro. When the same culture supernatant was added to ASCs isolated from normal subjects augmentation of the mRNA expressions of IL-4, IL-10, IL-8, MMP2, VEGF and SDF-1 in normal ASCs was also observed. These data collectively conclude that resident ASCs in breast cancer tissue may have crucial roles in breast tumor growth and progression by inducing regulatory molecules and promoting anti-inflammatory reaction within the tumor microenvironment. Further investigation is required to see if the immune suppression induced by ASCs is an independent property from tumor cells or ASCs gain their immunosuppressive potential from malignant cells.

Immunopathogenesis of lymphoma: focus on CCR4.

Evading immune surveillance is one of the common hallmarks of cancer. Herein we describe two major evasion mechanisms in lymphoma, focusing on regulatory T (Treg) cells and C-C chemokine receptor 4 (CCR4) expressed on these cells. First, the tumor cells themselves function as Treg cells, characterized by expression of CCR4, contributing to tumor survival by downregulating host immunity. Second, CCR4 ligands are produced by tumor cells, which attract other CCR4(+) Treg cells to the vicinity of the tumor. CCR4(+) adult T-cell leukemia//lymphoma is an example of the former phenomenon, and Hodgkin lymphoma of the latter, for which an almost identical immunopathogenesis has been reported in many types of cancer. Awareness of the importance of CCR4 allows the rational design of more effective cancer treatments. Accordingly, we have developed a defucosylated anti-CCR4 mAb, the first therapeutic agent targeting CCR4 to be used clinically for cancer. The therapeutic anti-CCR4 mAb represents a promising treatment method for patients with CCR4(+) neoplasms by directly killing the cancer cells, but could also be used as a novel treatment strategy for many types of CCR4(-) cancers to overcome the suppressive effect of CCR4(+) Treg cells.

Leukaemic cutaneous T-cell lymphoma-manifesting papuloerythroderma with CD3(-) CD4(+) phenotype.

The leukaemic form of cutaneous T-cell lymphoma, as represented by Sézary syndrome, exhibits erythroderma. We describe here an indolent leukaemic patient with cutaneous T-cell lymphoma, who initially had a nodulo-tumourous eruption with a crop of solid papules, but finally presented with papuloerythroderma. Histologically, the skin lesions showed non-epidermotropic dermal infiltration of atypical lymphocytes with lymphoid follicles and a granulomatous change. The circulating malignant CD4(+) CCR4(+) T cells lacked the expression of T-cell receptor and did not respond to concanavalin A. The unresponsiveness of T cells to the T-cell mitogen may be associated with the non-epidermotropic behaviour of the tumour cells and the initially non-erythrodermic eruption.