Tumour-immune cell interactions modulated by chemokines

The Chemokines CXC, CC and C in the Pathogenesis of COVID-19 Disease and as Surrogates of Vaccine-Induced Innate and Adaptive Protective Responses

COVID-19 is one of the progressive viral pandemics that originated from East Asia. COVID-19 or SARS-CoV-2 has been shown to be associated with a chain of physio-pathological mechanisms that are basically immunological in nature. In addition, chemokines have been proposed as a subgroup of chemotactic cytokines with different activities ranging from leukocyte recruitment to injury sites, irritation, and inflammation to angiostasis and angiogenesis. Therefore, researchers have categorized the chemotactic elements into four classes, including CX3C, CXC, CC, and C, based on the location of the cysteine motifs in their structures. Considering the severe cases of COVID-19, the hyperproduction of particular chemokines occurring in lung tissue as well as pro-inflammatory cytokines significantly worsen the disease prognosis. According to the studies conducted in the field documenting the changing expression of CXC and CC chemokines in COVID-19 cases, the CC and CXC chemokines contribute to this pandemic, and their impact could reflect the development of reasonable strategies for COVID-19 management. The CC and the CXC families of chemokines are important in host immunity to viral infections and along with other biomarkers can serve as the surrogates of vaccine-induced innate and adaptive protective responses, facilitating the improvement of vaccine efficacy. Furthermore, the immunogenicity elicited by the chemokine response to adenovirus vector vaccines may constitute the basis of vaccine-induced immune thrombotic thrombocytopaenia.

Exploring Tumor Immune Microenvironment and Its Associations With Molecular Characteristics in Melanoma

Background

The tumor microenvironment (TME), which involves infiltration of multiple immune cells into the tumor tissues, plays an essential role in clinical benefit to therapy. The chemokines and their receptors influence migration and functions of both tumor and immune cells. Also, molecular characteristics are associated with the efficacy of melanoma therapy. However, there lacked exploration of immune characteristics and the association with molecular characteristics.

Methods

We collected the currently available 569 melanoma samples that had both the genomic and transcriptional data from TCGA and SRA databases. We first identified TME subtypes based on the developed immune signatures, and then divided the samples into two immune cohorts based on the immune score. Next, we estimated the compositions of the immune cells of the two cohorts, and performed differential expression genes (DEGs) and functional enrichments. In addition, we investigated the interactions of chemokines and their receptors under immune cells. Finally, we explored the genomic characteristics under different immune subtypes.

Results

TME type D had a better prognosis among the four subtypes. The high-immunity cohort had significantly high 16 immune cells. The 63 upregulated and 384 downregulated genes in the high-immunity cohort were enriched in immune-related biological processes, and keratin, pigmentation and epithelial cells, respectively. The correlations of chemokines and their receptors with immune cell infiltration, such as CCR5-CCL4/CCL5 and CXCR3-CXCL9/CXCL10/CXCL11/CXCL13 axis, showed that the recruitments of 11 immune cells, such as CD4T cells and CD8T cells, were modulated by chemokines and their receptors. The proportions of the four TME subtypes in each molecular subtype were comparable. The two driver genes, CDKN2A and PRB2, had significantly different MAFs between the high-immunity and low-immunity.

Conclusion

We dissected the characteristics of immune infiltration, the interactions of chemokines and their receptors under immune cells, and the correlation of molecular and immune characteristics. Our work will enable the reasonable selection of anti-melanoma treatments and accelerate the development of new therapeutic strategies for melanoma.

Safety levels of systemic IL-12 induced by cDNA expression as a cancer therapeutic

Aim: The aim of this work is to utilize a gene expression procedure to safely express systemic IL-12 and evaluate its effects in mouse tumor models. Materials & methods: Secondary lymphoid organs and tumors from EL4 and B16 tumor-bearing mice were analyzed by supervised and unsupervised methods. Results: IL-12 cDNA induced systemic IL-12 protein levels lower than the tolerated dose in patients. Control of tumor growth was observed in subcutaneous B16 and EL4 tumors. Systemic IL-12 expression induced a higher frequency of both total tumor-infiltrated CD45⁺ cells and proliferative IFN-γ⁺CD8⁺ T cells along with a lower frequency of CD4⁺FOXP3⁺ and CD11b⁺Gr-1⁺ cells. Conclusion: This approach characterizes the systemic effects of IL-12, helping to improve treatment of metastases or solid tumors.

The Involvement of CXC Motif Chemokine Ligand 10 (CXCL10) and Its Related Chemokines in the Pathogenesis of Coronary Artery Disease and in the COVID-19 Vaccination: A Narrative Review

Coronary artery disease (CAD) and coronary heart disease (CHD) constitute two of the leading causes of death in Europe, USA and the rest of the world. According to the latest reports of the Iranian National Health Ministry, CAD is the main cause of death in Iranian patients with an age over 35 years despite a significant reduction in mortality due to early interventional treatments in the context of an acute coronary syndrome (ACS). Inflammation plays a fundamental role in coronary atherogenesis, atherosclerotic plaque formation, acute coronary thrombosis and CAD establishment. Chemokines are well-recognized mediators of inflammation involved in several bio-functions such as leucocyte migration in response to inflammatory signals and oxidative vascular injury. Different chemokines serve as chemo-attractants for a wide variety of cell types including immune cells. CXC motif chemokine ligand 10 (CXCL10), also known as interferon gamma-induced protein 10 (IP-10/CXLC10), is a chemokine with inflammatory features whereas CXC chemokine receptor 3 (CXCR3) serves as a shared receptor for CXCL9, 10 and 11. These chemokines mediate immune responses through the activation and recruitment of leukocytes, eosinophils, monocytes and natural killer (NK) cells. CXCL10, interleukin (IL-15) and interferon (IFN-g) are increased after a COVID-19 vaccination with a BNT162b2 mRNA (Pfizer/BioNTech) vaccine and are enriched by tumor necrosis factor alpha (TNF-α) and IL-6 after the second vaccination. The aim of the present study is the presentation of the elucidation of the crucial role of CXCL10 in the patho-physiology and pathogenesis of CAD and in identifying markers associated with the vaccination resulting in antibody development.

Discovery of rare sulfated N-unsubstituted glucosamine based heparan sulfate analogs selectively activating chemokines

Achieving selective inhibition of chemokines with structurally well-defined heparan sulfate (HS) oligosaccharides can provide important insights into cancer cell migration and metastasis. However, HS is highly heterogeneous in chemical composition, which limits its therapeutic use. Here, we report the rational design and synthesis of N-unsubstituted (NU) and N-acetylated (NA) heparan sulfate tetrasaccharides that selectively inhibit structurally homologous chemokines. HS analogs were produced by divergent synthesis, where fully protected HS tetrasaccharide precursor was subjected to selective deprotection and regioselectively O-sulfated, and O-phosphorylated to obtain 13 novel HS tetrasaccharides. HS microarray and SPR analysis with a wide range of chemokines revealed the structural significance of sulfation patterns and NU domain in chemokine activities for the first time. Particularly, HT-3,6S-NH revealed selective recognition by CCL2 chemokine. Further systematic interrogation of the role of HT-3,6S-NH in cancer demonstrated an effective blockade of CCL2 and its receptor CCR2 interactions, thereby impairing cancer cell proliferation, migration and invasion, a step towards designing novel drug molecules.

The role of CXC chemokine ligand 16 in physiological and pathological pregnancies

The survival and development of a semi-allogeneic fetus during pregnancy require the involvement of a series of cytokines and immune cells. Chemokines are a type of special cytokine those were originally described as having a role in leukocyte trafficking. CXC chemokine ligand (CXCL) 16 is a member of the chemokine family, and CXC chemokine receptor (CXCR) 6 is its sole receptor. Emerging evidence has shown that CXCL16/CXCR6 is expressed at the maternal-fetal interface, by cell types that include trophoblast cells, decidual stroma cells, and decidual immune cells (eg, monocytes, γδT cells, and natural killer T (NKT) cells). The regulation of expression of CXCL16 is quite complex, and this process involves a multitude of factors. CXCL16 exerts a critical role in the establishment of a successful pregnancy through a series of molecular interactions at the maternal-fetal interface. However, an abnormal expression of CXCL16 is associated with certain pathological states associated with pregnancy, including recurrent miscarriage, pre-eclampsia, and gestational diabetes mellitus (GDM). In the present review, the expression and pleiotropic roles of CXCL16 under conditions of physiological and pathological pregnancy are systematically discussed.

CDK2-mediated site-specific phosphorylation of EZH2 drives and maintains triple-negative breast cancer

Triple-negative breast cancer (TNBC), which lacks estrogen receptor α (ERα), progesterone receptor, and human epidermal growth factor receptor 2 (HER2) expression, is closely related to basal-like breast cancer. Previously, we and others report that cyclin E/cyclin-dependent kinase 2 (CDK2) phosphorylates enhancer of zeste homolog 2 (EZH2) at T416 (pT416-EZH2). Here, we show that transgenic expression of phospho-mimicking EZH2 mutant EZH2^T416D in mammary glands leads to tumors with TNBC phenotype. Coexpression of EZH2^T416D in mammary epithelia of HER2/Neu transgenic mice reprograms HER2-driven luminal tumors into basal-like tumors. Pharmacological inhibition of CDK2 or EZH2 allows re-expression of ERα and converts TNBC to luminal ERα-positive, rendering TNBC cells targetable by tamoxifen. Furthermore, the combination of either CDK2 or EZH2 inhibitor with tamoxifen effectively suppresses tumor growth and markedly improves the survival of the mice bearing TNBC tumors, suggesting that the mechanism-based combination therapy may be an alternative approach to treat TNBC.

EZH2 phosphorylation by CDK2 promotes progression of triple-negative breast cancer (TNBC). Here, the authors show that this signaling axis downregulates ERα, and thus combinatorial blockade of CDK2 and EZH2 sensitizes TNBC cells to tamoxifen.

Chemokines as adjuvants for immunotherapy: implications for immune activation with CCL3

INTRODUCTION

Immunotherapy embodies any approach that manipulates the immune system for therapeutic benefit. In this regard, various clinical trials have employed direct vaccination with patient-specific dendritic cells or adoptive T cell therapy to target highly aggressive tumors. Both modalities have demonstrated great specificity, an advantage that is unmatched by other treatment strategies. However, their full potential has yet to be realized. Areas covered: In this review, we provide an overview of chemokines in pathogen and anti-tumor immune responses and discuss further improving immunotherapies by arming particular chemokine axes. Expert commentary: The chemokine macrophage inflammatory protein-1 alpha (MIP-1α, CCL3) has emerged as a potent activator of both innate and adaptive responses. Specifically, CCL3 plays a critical role in recruiting distinct immune phenotypes to intratumoral sites, is a pivotal player in regulating lymph node homing of dendritic cell subsets, and induces antigen-specific T cell responses. The recent breadth of literature outlines the various interactions of CCL3 with these cellular subsets, which have now served as a basis for immunotherapeutic translation.

Association of CCR2 (+190 G/A) Gene Variants and Ovarian Cancer Severity

AIM

Chemokines and their receptors play an important role in tumor progression. In the current study, we aimed to determine the association between the CCR2 gene (+190 G/A) polymorphism and ovarian cancer severity.

METHODS

CCR2 (+190 G/A) genotyping was performed using real-time polymerase chain reaction for DNA isolated from blood samples from a cohort of patients with ovarian cancer (n = 44) and a control group (n = 45).

RESULTS

The CCR2 (+190 G/A) GG genotype frequencies for patients were significantly higher in the stage III-IV cancer group (p = 0.036), and A allele carriers were significantly higher in the stage I-II ovarian cancer group.

CONCLUSION

The CCR2 (+190 G/A) GG genotype may be a potential risk factor for the severe forms of ovarian cancer and the A allele may be a risk-reducing factor for severe ovarian cancer.

NF-κB signaling regulates cell-autonomous regulation of CXCL10 in breast cancer 4T1 cells

The chemokine CXCL10 and its receptor CXCR3 play a role in breast cancer metastasis to bone and osteoclast activation. However, the mechanism of CXCL10/CXCR3-induced intracellular signaling has not been fully investigated. To evaluate CXCL10-induced cellular events in the mouse breast cancer cell line 4T1, we developed a new synthetic CXCR3 antagonist JN-2. In this study, we observed that secretion of CXCL10 in the supernatant of 4T1 cells was gradually increased during cell growth. JN-2 inhibited basal and CXCL10-induced CXCL10 expression and cell motility in 4T1 cells. Treatment of 4T1 cells with CXCL10 increased the expression of P65, a subunit of the NF-κB pathway, via activation of the NF-κB transcriptional activity. Ectopic overexpression of P65 increased CXCL10 secretion and blunted JN-2-induced suppression of CXCL10 secretion, whereas overexpression of IκBα suppressed CXCL10 secretion. These results indicate that the CXCL10/CXCR3 axis creates a positive feedback loop through the canonical NF-κB signaling pathway in 4T1 cells. In addition, treatment of osteoblasts with conditioned medium from JN-2-treated 4T1 cells inhibited the expression of RANKL, a crucial cytokine for osteoclast differentiation, which resulted in an inhibitory effect on osteoclast differentiation in the co-culture system of bone marrow-derived macrophages and osteoblasts. Direct intrafemoral injection of 4T1 cells induced severe bone destruction; however, this effect was suppressed by the CXCR3 antagonist via downregulation of P65 expression in an animal model. Collectively, these results suggest that the CXCL10/CXCR3-mediated NF-κB signaling pathway plays a role in the control of autonomous regulation of CXCL10 and malignant tumor properties in breast cancer 4T1 cells.

Serum CXCL10 and CXCL12 chemokine levels are associated with the severity of coronary artery disease and coronary artery occlusion

BACKGROUND

Cardiovascular disease constitutes a major cause of death worldwide. Inflammation plays an important role in atherosclerosis formation, coronary artery disease progression, acute coronary thrombosis and occlusion. Chemokines are inflammatory mediators disposing several bio-functions, as leukocyte migration towards inflammatory signals and vascular injuries. The present study was designed to evaluate the potential correlation between serum levels of chemokines CXCL-10 and CXCL-12 and the degree of coronary artery occlusion.

METHODS

Eighty eight patient candidates for coronary angiography with coronary artery disease symptoms and potentially high risk of coronary artery occlusion were recruited. Chemokine serum levels were measured with the ELISA method and patients underwent coronary angiography. All patients with coronary artery disease (CAD) were divided into four groups according to the Gensini score. Data were presented as mean±SD. All P values <0.05 were considered significant.

RESULTS

Our demographic data showed that of the 88 patients, 46 were male and 42 female. The mean age of patients was 57.95±11.13. Following increased coronary artery occlusion the serum levels of chemokines were significantly increased (CXCL-10 and CXCL-12; P<0.0001 and P<0.0001, respectively).

CONCLUSION

In this novel study, a significant correlation between the serum levels of CXCL-10 and CXCL-12 and the severity of coronary artery occlusion was found. This could be attributed to the role of these chemokines in the processes of angiogenesis and angiostasis, a biological phenomenon that can play key role in the development of collateral circulation.

CCL3 promotes angiogenesis by dysregulation of miR-374b/ VEGF-A axis in human osteosarcoma cells

Osteosarcoma is the most frequent bone tumor, characterized by a high metastatic potential. However, the crosstalk between chemokine (C-C motif) ligand 3 (CCL3), which facilitates tumor progression and metastasis. Vascular endothelial growth factor-A (VEGF-A), an angiogenesis inducer and a highly specific mitogen for endothelial cells, has not been well explored in human osteosarcoma. Here we demonstrate the correlation of CCL3 and VEGF-A expressions, quantified by immunohistochemistry, with the tumor stage of human osteosarcoma tissues. Furthermore, CCL3 promotes VEGF-A expression in human osteosarcoma cells that subsequently induces human endothelial progenitor cell (EPC) migration and tube formation. Phosphorylation of JNK, ERK, and p38 was found after CCL3 stimulation. In addition, JNK, ERK, and p38 inhibitors also abolished CCL3-induced VEGF-A expression and angiogenesis. We noted that CCL3 reduces the expression of miR-374b and miR-374b mimic by reversing CCL3-promoted VEGF-A expression and angiogenesis in vitro and in vivo. This study shows that CCL3 promotes VEGF-A expression and angiogenesis in human osteosarcoma cells by down-regulating miR-374b expression via JNK, ERK, and p38 signaling pathways. Thus, CCL3 may be a new molecular therapeutic target in osteosarcoma angiogenesis and metastasis.

Chemokine Expression Profiles of Human Hepatoma Cell Lines Mediated by Hepatitis B Virus X Protein

The hepatitis B virus X protein (HBx), which is encoded by hepatitis B virus (HBV), plays crucial roles in the tumorigenesis of HBV associated hepatocellular carcinoma (HCC). Recent studies suggest that the HBx is involved in regulation of host immune cytokines and chemokines in HBV-associated HCC patients. However, effects of the HBx on autocrine chemokine expression profiles of hepatoma cells, which were shown in modulation of tumor-immune cell interactions, have not been investigated comprehensively. In the present study, human hepatoma cell lines SMMC-7721 and HepG2 were transfected with HBx-expressing plasmid. Human chemokine antibody array 1 (RayBio®), which simultaneously detects 38 chemokine factors, was used to determine chemokine expression profiles. Real-time polymerase chain reaction (real-time PCR) was used to further confirm the differential expression of chemokines. Chemokine antibody array revealed that all 38 chomekines were found to be expressed by SMMC-7721 and HepG2 cell lines. Interleukin-8 (IL-8) was obviously up-regulated, and epithelial neutrophil-activating protein 78 (ENA78), eosinophil chemotactic protein-1 (Eotaxin-1), monocyte chemotactic protein-1 (MCP-1), MCP-2, MCP-3 and macrophage inflammatory protein-3β (MIP-3β) were significantly declined in both cell lines following transfection of HBx-expressing plasmid. Other chemokines showed little or no significant changes. HBx-induced differential chemokine expression levels were validated by real-time PCR. Hierarchical cluster analysis identified a distinction of chomekine expression profiles between HBX-expressing hepatoma cell lines and controls. Our findings provide new evidence that HBx is able to selectively regulate chomekines in hepatoma cells that may be involved in the regulation of tumor-immune cell interactions.

STAT3 in CD8+ T Cells Inhibits Their Tumor Accumulation by Downregulating CXCR3/CXCL10 Axis

One of the obstacles for cancer immunotherapy is the inefficiency of CD8(+) T-cell recruitment to tumors. STAT3 has been shown to suppress CD8(+) T-cell antitumor functions in various cancer models, in part by restricting accumulation of CD8(+) T cells. However, the underlying molecular mechanism by which STAT3 in CD8(+) T cells inhibits their accumulation in tumors remains to be defined. Here, we show that STAT3 signaling in CD8(+) T cells inhibits chemokine CXCL10 production by tumor-associated myeloid cells by reducing IFNγ expression by T cells. We further demonstrate that ablating STAT3 in T cells allows expression of CXCR3, the receptor of CXCL10, on CD8(+) T cells, resulting in efficient accumulation of CD8(+) T cells at tumor sites. Blocking IFNγ or CXCR3 impairs the accumulation of STAT3-deficient CD8(+) T cells in tumor and their antitumor effects. Together, our study reveals a negative regulation by STAT3 signaling in T cells on cross-talk between myeloid cells and T cells through IFNγ/CXCR3/CXCL10, which is important for CD8(+) T cells homing to tumors. Our results thus provide new insights applicable to cancer immunotherapy and adoptive T-cell strategies.

TLR5 Ligand-Secreting T Cells Reshape the Tumor Microenvironment and Enhance Antitumor Activity

The tumor microenvironment counters antitumor T-cell responses, in part, by blunting their activation and infiltration. Ligands that engage Toll-like receptors (TLR) on T cells and antigen-presenting cells can act as potent immune adjuvants. In this study, we show how tumor-reactive T cells engineered to secrete bacterial flagellin, a TLR5 ligand (TLR5L), can engender a costimulatory signal that augments antitumor activity. Human T cells engineered to express TLR5L along with DMF5, a T-cell receptor that recognizes the melanoma antigen MART-127-35 (DMF5(TLR5L) T cells), displayed increased proliferation, cytokine production, and cytolytic activity against melanoma cells. In a xenogenetic model, adoptive transfer of DMF5(TLR5L) T cells reduced tumor growth kinetics and prolonged mouse survival. In a syngeneic model, similarly engineered melanoma-reactive T cells (pmel(TLR5L)) displayed a relative increase in antitumor activity against established tumors, compared with unmodified T cells. In this model, we documented increased T-cell infiltration associated with increased levels of CCR1 and CXCR3 levels on T cells, a reduction in PD-1(+)Lag3(+) T cells and CD11(+)Gr1(+) myeloid-derived suppressor cells, and changes in the chemokine/cytokine profile of tumors. Our findings show how T cell-mediated delivery of a TLR agonist to the tumor site can contribute to antitumor efficacy, in the context of adoptive T-cell immunotherapy.

Adipocyte-derived players in hematologic tumors: useful novel targets?

INTRODUCTION

Adipocytes and their products play essential roles in tumor establishment and progression. As the main cellular component of the bone marrow, adipocytes may contribute to the development of hematologic tumors.

AREAS COVERED

This review summarizes experimental data on adipocytes and their interaction with various cancer cells. Special focus is set on the interactions of bone marrow adipocytes and normal and transformed cells of the hematopoietic system such as myeloma and leukemia cells. Current in vitro and in vivo data are summarized and the potential of novel therapeutic targets is critically discussed.

EXPERT OPINION

Targeting lipid metabolism of cancer cells and adipocytes in combination with standard therapeutics might open novel therapeutic avenues in these cancer entities. Adipocyte-derived products such as free fatty acids and specific adipokines such as adiponectin may be vital anti-cancer targets in hematologic malignancies. However, available data on lipid metabolism is currently mostly referring to peripheral fat cell/cancer cell interactions and results need to be evaluated specifically for the bone marrow niche.

Synaptic release of CCL5 storage vesicles triggers CXCR4 surface expression promoting CTL migration in response to CXCL12

The lytic function of CTL relies on the polarized release of cytotoxic granules (CG) at the immune synapse (IS) with target cells. CTL also contain CCL5 in cytoplasmic storage vesicles (CCL5V) distinct from CG, the role of which, in regulating T cell effector functions, is not understood. Using human CD8(+) T cells specific to a lung tumor-associated Ag, we show in this article that CTL release both secretory compartments into the immune synapse with autologous tumor cells. Moreover, we demonstrate that disorganization of the T cell microtubule cytoskeleton and defects in hMunc13-4 or Rab27a abrogate CG exocytosis and synaptic secretion of the chemokine. Mechanistically, synaptic release of CCL5 cytoplasmic storage vesicles likely occurs upon their coalescence with the Rab27a-hMunc13-4 compartment and results in autocrine, CCR5-dependent induction of CXCR4 cell surface expression, thereby promoting T cell migration in response to CXCL12. We propose that CCL5 polarized delivery represents a mechanism by which CTL control immune synapse duration.

The effect of CCL19/CCR7 on the proliferation and migration of cell in prostate cancer

Multiple studies have shown that CC motif chemokine ligand 19 (CCL19) promotes cell proliferation in several human cancers. In this study, we investigated the clinical significance of CCL19 and its specific receptor CCR7 and its function in our large collection of prostate samples. Between August 2000 and December 2013, 108 patients with histologically confirmed prostate cancer (PCa) and 80 with benign prostate hyperplasia (BPH) were recruited into the study. Quantitative RT-PCR immunohistochemistry analyses were used to quantify CCL19 and CCR7 expression in PCa cell lines and clinical samples. The functional role of CCL19 in PCa cell lines was evaluated by small interfering RNA-mediated depletion of the protein followed by analyses of cell proliferation and invasion. The positive rate of CCL19 staining was 87.04 % (94/108) in 108 cases of prostatic carcinoma and 16.25 % (13/80) in 80 cases of BPH, and high expression of CCR7 was observed in 83.33 % (90/108) of the PCa tissues versus (17.50 %; 14/80) of the BPH tissues, the difference of CCL19 and CCR7 expression between two groups was statistically significant, respectively. The results were confirmed by quantitative real-time PCR. CCL19 and CCR7 were significantly elevated in all five PCa cell lines when compared to the RWPE-1 cells. Silencing of CCL19 inhibited the proliferation of DU-145 cells which have a relatively high level of CCL19 in a time- and concentration-dependent manner, and the invasion and migration of DU-145 cells were distinctly suppressed. Our data suggest that the pathogenesis of human PCa maybe mediated by the CCL19/CCR7 axis, and CCL19 inhibition treatment may provide a promising strategy for the anti-tumor therapy of PCa.

The effect of chemokine CC motif ligand 19 on the proliferation and migration of hepatocellular carcinoma

Multiple studies have shown that CC motif chemokine ligand 19 (CCL19) promotes cell proliferation in several human cancers. The aim of this study was to investigate the expression and function of CCL19 in hepatocellular carcinoma (HCC). Quantitative reverse transcription-polymerase chain reaction (qRT-PCR), Western blot, and immunohistochemistry were performed separately to detect the expression of CCL19 in HCC tissues. The expression of CCL19 and its receptor (CCR7) in different HCC cell lines were screened by Western blot. HCC cell lines were screened and processed with recombinant human CCL19 (rhCCL19) or si-CCL19 RNA. Cell proliferation assay and transwell assay were performed to evaluate the proliferation and migration of HCC cells, respectively. Low expression of CCL19 was observed in 83.72 % (72/86) of the HCC versus 16.67 % (4/24) of the adjacent non-tumorous liver tissues, the difference of CCL19 expression between HCC and adjacent non-tumorous liver tissues was statistically significant (P < 0.001). The expression level of CCL19 mRNA and protein in tumor tissues was significantly lower than adjacent non-tumorous liver tissues. The proliferation and migration of HCC cells were obviously inhibited in rhCCL19-treated groups. Our data suggest that CCL19 may play a suppressive role in the regulation of aggressiveness in human HCC.

Intravenous injection of MVA virus targets CD8+ lymphocytes to tumors to control tumor growth upon combinatorial treatment with a TLR9 agonist

Effector T-cell access to tumor tissue is a limiting step for clinical efficacy of antigen-specific T cell-based immunotherapies. Ectopic mouse tumor models, in which a subcutaneously (s.c.) implanted tumor is treated with s.c. or intramuscular therapeutic immunization, may not be optimal for targeting effector T cells to an organ-borne tumor. We used an orthotopic renal carcinoma model to evaluate the impact of injection routes on therapeutic efficacy of a Modified Vaccinia virus Ankara viral vector expressing the human mucin 1 tumor-associated xeno-antigen (MVA-MUC1). We show that intravenous (i.v.) administration of MVA-MUC1 displayed enhanced efficacy when compared with s.c. injection. Therapeutic efficacy of MVA-MUC1 was further enhanced by i.v. injection of a TLR9 agonist. In all cases, infiltration of tumor-bearing kidney by CD8(+) lymphocytes was associated with control of tumor growth. Biodistribution experiments indicate that, following i.v. injection, MVA-encoded antigens are quickly expressed in visceral organs and, in particular, in splenic antigen-presenting cells, compared with those following s.c. injection. This appears to result in a faster generation of MUC1-specific CD8(+) T cells. Lymphocytes infiltrating tumor-bearing kidneys are characterized by an effector memory phenotype and express PD-1 and Tim3 immune checkpoint molecules. Therapeutic efficacy was associated with a modification of the tumor microenvironment toward a Th1-type immune response and recruitment of activated lymphocytes. This study supports the clinical evaluation of MVA-based immunotherapies via the i.v. route.

The integrative roles of chemokines at the maternal-fetal interface in early pregnancy

Embryos express paternal antigens that are foreign to the mother, but the mother provides a special immune milieu at the fetal-maternal interface to permit rather than reject the embryo growth in the uterus until parturition by establishing precise crosstalk between the mother and the fetus. There are unanswered questions in the maintenance of pregnancy, including the poorly understood phenomenon of maternal tolerance to the allogeneic conceptus, and the remarkable biological roles of placental trophoblasts that invade the uterine wall. Chemokines are multifunctional molecules initially described as having a role in leukocyte trafficking and later found to participate in developmental processes such as differentiation and directed migration. It is increasingly evident that the gestational uterine microenvironment is characterized, at least in part, by the differential expression and secretion of chemokines that induce selective trafficking of leukocyte subsets to the maternal-fetal interface and regulate multiple events that are closely associated with normal pregnancy. Here, we review the expression and function of chemokines and their receptors at the maternal-fetal interface, with a special focus on chemokine as a key component in trophoblast invasiveness and placental angiogenesis, recruitment and instruction of immune cells so as to form a fetus-supporting milieu during pregnancy. The chemokine network is also involved in pregnancy complications.

Antitumor efficacy of C-X-C motif chemokine ligand 14 in hepatocellular carcinoma in vitro and in vivo

C-X-C motif chemokine ligand 14 (CXCL14) is a novel gene that is expressed in many normal cells but is absent from or expressed at very low levels in cancerous tissues such as head and neck squamous cell carcinoma (HNSCC), prostate cancer, and pancreatic cancer. However, the relationship between CXCL14 and hepatocellular carcinoma (HCC) remains unclear. Therefore, the exact function of CXCL14, which may modulate antitumor immune responses in certain cancers, was evaluated. CXCL14 was downregulated in HCC tissues compared to adjacent normal tissues. Moreover, overexpression of CXCL14 had an inhibitory effect on cell proliferation, induced apoptosis and inhibited the invasion of HCC cells in vitro. Upregulation of CXCL14 by lentivirus also significantly suppressed the growth of subcutaneous tumors in nude mice in vivo. We further demonstrated that the loss of CXCL14 expression was regulated by promoter hypermethylation. CXCL14 induced tumor cell apoptosis through both the mitochondrial and nuclear apoptosis pathways. CXCL14 suppressed tumor cell proliferation through regulation of the cell cycle by downregulation of cyclins and cyclin-dependent kinases. In conclusion, CXCL14 plays a pivotal role as a potential tumor suppressor in HCC. The re-expression or upregulation of this gene may provide a novel strategy in HCC therapy in the future.

CXCR7-mediated progression of osteosarcoma in the lungs

Background:

Osteosarcoma (OS) is the most frequent primary malignant bone tumour in children and adolescents with a high propensity for lung metastasis. Chemokines and chemokine receptors have been described to have an important role in many malignancies including OS. The aim of this study was to investigate the expression of CXCR7 receptor in OS tissues and its role in the progression of the disease in the lungs.

Methods:

Immunohistochemistry was used to study CXCR7 expression in primary tumours and metastatic tissues from patients with OS. Its contribution to tumour expansion in the lungs has been also assessed using animal models and synthetic-specific CXCR7 ligands.

Results:

CXCR7 was expressed on human primary bone tumours and on lung metastases. Its expression was predominantly located on tumour-associated blood vessels. Mice challenged with OS cells and systematically treated with synthetic CXCR7 ligands presented a significant reduction of lung nodules compared with untreated mice.

Conclusion:

This study shows that CXCR7 has a critical role in OS progression in the lungs, where are expressed CXCR7 ligands, especially CXCL12. Moreover, we highlight that synthetic CXCR7 ligands could represent a powerful therapeutic tool to impede lung OS progression.

Expression of leukotriene B₄ receptor-1 on CD8⁺ T cells is required for their migration into tumors to elicit effective antitumor immunity

Leukotriene B₄ (LTB₄) receptor (BLT)1 is expressed on variety of immune cells and has been implicated as a mediator of diverse inflammatory diseases. However, whether biological responses initiated via this receptor generate tumor-promoting inflammation or antitumor immunity remains unexplored. In this study, we investigated the role of BLT1 in antitumor immunity using syngeneic TC-1 cervical cancer model, and observed accelerated tumor growth and reduced survival in BLT1⁻/⁻ mice compared with BLT1⁺/⁺ mice. Analysis of the tumor infiltrates by flow cytometry and confocal microscopy revealed a significant decrease in effector immune cells, most notably, CD8⁺ T cells and NK cells in the tumors of the BLT1⁻/⁻ mice. Gene expression profiling confirmed the dramatic decrease of IFN-γ, granzyme B, and IL-2 in tumors growing in BLT1⁻/⁻ mice. Furthermore, depletion of CD8⁺ T cells enhanced the tumor growth in BLT1⁺/⁺ but not in BLT1⁻/⁻ mice. However, similar levels of Ag-dependent CD8⁺ T cell-mediated killing activity were observed in spleens of BLT1⁺/⁺ and BLT1⁻/⁻ mice. Adoptive transfer of CD8⁺ T cells from tumor-bearing BLT1⁺/⁺ but not BLT1⁻/⁻ mice significantly reduced tumor growth and increased the survival of Rag2⁻/⁻ mice. Although the homeostatic proliferation and expression profiles of other chemokine receptors of adoptively transferred BLT1⁺/⁺ and BLT1⁻/⁻ CD8⁺ T cells appears to be similar, BLT1⁺/⁺ T lymphocytes entered the tumors in greater numbers. These results suggest that BLT1 expression on CD8⁺ T cells plays an important role in their trafficking to tumors.

Chemokine CXCL14 is associated with prognosis in patients with colorectal carcinoma after curative resection

Background

The chemokine CXCL14 has been reported to play an important role in the progression of many malignancies such as breast cancer and papillary thyroid carcinoma, but the role of CXCL14 in colorectal carcinoma (CRC) remains to be established. The purpose of this study was to investigate the expression pattern and significance of CXCL14 in CRC progression.

Method

265 colorectal carcinoma specimens and 129 matched adjacent normal colorectal mucosa specimens were collected. Expression of CXCL14 in clinical samples was examined by immunostaining. The effect of CXCL14 on colorectal carcinoma cell proliferation was measured by MTT assay, BrdU incorporation assay and colony formation assay. The impact of CXCL14 on migration and invasion of colorectal carcinoma cells was determined by transwell assay and Matrigel invasion assay, respectively.

Results

CXCL14 expression was significantly up-regulated in tumor tissues compared with adjacent nontumorous mucosa tissues (P < 0.001). Tumoral CXCL14 expression levels were significantly correlated with TNM (Tumor-node-metastasis) stage, histodifferentiation, and tumor size. In multivariate Cox regression analysis, high CXCL14 expression in tumor specimens (n = 91) from stage I/II patients was associated with increased risk for disease recurrence (risk ratio, 2.92; 95% CI, 1.15-7.40; P = 0.024). Elevated CXCL14 expression in tumor specimens (n = 135) from stage III/IV patients correlated with worse overall survival (risk ratio, 3.087; 95% CI, 1.866-5.107; P < 0.001). Functional studies demonstrated that enforced expression of CXCL14 in SW620 colorectal carcinoma cells resulted in more aggressive phenotypes. In contrast, knockdown of CXCL14 expression could mitigate the proliferative, migratory and invasive potential of HCT116 colorectal carcinoma cells.

Conclusion

Taken together, CXCL14 might be a potential novel prognostic factor to predict the disease recurrence and overall survival and could be a potential target of postoperative adjuvant therapy in CRC patients.

Role of chemokines and chemokine receptors in shaping the effector phase of the antitumor immune response

Immune system-mediated eradication of neoplastic cells requires induction of a strong long-lasting antitumor T-cell response. However, generation of tumor-specific effector T cells does not necessarily result in tumor clearance. CTL must first be able to migrate to the tumor site, infiltrate the tumor tissue, and interact with the target to finally trigger effector functions indispensable for tumor destruction. Chemokines are involved in circulation, homing, retention, and activation of immunocompetent cells. Although some of them are known to contribute to tumor growth and metastasis, others are responsible for changes in the tumor microenvironment that lead to extensive infiltration of lymphocytes, resulting in tumor eradication. Given their chemoattractive and activating properties, a role for chemokines in the development of the effector phase of the antitumor immune response has been suggested. Here, we emphasize the role of the chemokine-chemokine receptor network at multiple levels of the T-cell-mediated antitumor immune response. The identification of chemokine-dependent molecular mechanisms implicated in tumor-specific CTL trafficking, retention, and regulation of their in situ effector functions may offer new perspectives for development of innovative immunotherapeutic approaches to cancer treatment.

Elevated pretreatment serum levels of interferon-inducible protein-10 (CXCL10) predict disease relapse and prognosis in diffuse large B-cell lymphoma patients

Although standard clinical prognostic factors predict outcome in diffuse large B-cell lymphoma (DLBCL), predicting the outcome of patients might be further refined using biological factors. We tested whether serum cytokines could provide prognostic information in DLBCL patients. Thirty cytokines were measured in pretreatment samples from newly diagnosed DLBCL patients using a multiplex ELISA. Sixty-nine patients treated with R-CHOP plus epratuzumab were used in an initial cohort and 185 patients treated with standard R-CHOP served as a subsequent validation cohort. In the initial cohort, elevated serum interleukin-10 [IL-10; hazard ratio (HR) = 6.6, P = 0.022], granulocyte macrophage colony-stimulating factor (HR = 10.8, P= 0.027) and IP-10 (interferon-inducible protein-10, CXCL10; HR = 3.32, P = 0.015) were associated with event-free survival (EFS). An identical analysis of the subsequent validation cohort confirmed that elevated serum levels of IP-10 were strongly associated with a poor EFS (HR = 2.42, P = 0.0007); and also identified interleukin-8 (IL-8; HR = 3.40, P = 0.00002) and interleukin-2 receptor (IL-2R, CD25; HR = 2.59, P = 0.0012) as significantly associated with prognosis. The prognostic significance of elevated IP-10 remained significant after adjustment for the International Prognostic Index (EFS - HR 1.99, P = 0.009, overall survival-HR 1.93, P = 0.021). Elevated pretreatment serum IP-10 levels are therefore associated with an increased likelihood of disease relapse and an inferior survival in patients with DLBCL.

Sarcoidal reactions in regional lymph nodes of patients with early stage non-small cell lung cancer predict improved disease-free survival: a pilot case-control study

Sarcoidal reactions occurring in regional lymph nodes of patients with non-small cell lung carcinoma appear to be limited to patients with stage I disease. The prognostic significance of this remains unknown. Such reactions are thought to represent a cell-mediated antitumor response and have been associated with improved outcomes in other solid organ malignancies. We performed a retrospective chart review of all patients undergoing lobectomy with curative intent for non-small cell lung carcinoma. Eligible cases were selected based on pathologic reports, with matched controls then drawn from the same surgical cohort. One hundred fifty-seven patients underwent lobectomy and lymph node dissection. Eight patients with sarcoidal granulomas present in regional lymph nodes were identified as cases and matched to 16 control subjects. All subjects were staged pN0. Disease recurrence was noted in no case subjects but in 7 (44%) of control subjects (P = .044, χ(2) = 4.051). The presence of sarcoidal reactions within regional lymph nodes of patients with non-small cell lung carcinoma predicts a lower rate of disease recurrence after definitive surgical resection. The exact mechanism by which antitumor immunity is achieved remains to be elucidated.

An intronic polymorphism rs2237062 in the CXCL14 gene influences HBV-related HCC progression in Chinese population

CXCL14 (C-X-C motif chemokine ligand 14) is a conserved member of chemokine family and functions as a chemoattractant for multiplicate immunocytes. CXCL14 expression is constitutive in normal tissues, but absent in wide range of epithelial tumors. Many reports have claimed its important role in tumorigenesis and vascularization. An association between rs2237062 polymorphism and hepatocellular carcinoma (HCC) susceptibility was found in patients with chronic HCV infection in Japanese population. Here we analyzed, by using a polymerase chain reaction-ligation detection reaction (PCR-LDR), the polymorphism in 202 non-HCC patients with HBV infection, 361 HBV-related HCC patients and 407 healthy controls. The aim was to detect the possible association of this single-nucleotide polymorphism (SNP) with HBV-related HCC susceptibility and progression. However, no association was found between rs2237062 polymorphism and susceptibility to HBV infection or HBV-related HCC. Intriguingly, our stratification analysis revealed that HBV-related HCC patients in advanced phase (TNM-II-IV stage) had significantly higher C allele frequency at this polymorphism than patients at early stage (TNM-I stage) (33.5% vs. 25.7%), and its odds ratio reached 1.47 (95% CI 1.06-2.04, P = 0.021). These results suggest that the rs2237062 polymorphism in the CXCL14 gene might influence HBV-related HCC progression in Chinese population.

Activation of CXCR7 receptor promotes oligodendroglial cell maturation

OBJECTIVE

Differentiation of oligodendroglial precursor cells is crucial for central nervous system (re)myelination and is influenced by multiple extrinsic and intrinsic factors. Chemokines, a group of small proteins, are highly conserved among mammals and have been implicated in a variety of biological processes during development, tissue homeostasis, and repair. We investigated whether the chemokine CXCL12 influences oligodendrocytes and what cellular differentiation/maturation processes are controlled by this molecule.

METHODS

Experimental autoimmune encephalomyelitis was induced using myelin oligodendrocyte glycoprotein. Immunostainings and quantitative gene expression analysis were used to study expression of the 2 currently known CXCL12 receptors on oligodendroglial cells. Stimulation of cultured primary oligodendroglial precursor cells was performed to determine the impact of the ligand/receptor interaction on morphological maturation and on myelin expression. Blocking and suppression experiments were conducted to reveal the identity of the transmitting receptor.

RESULTS

This analysis revealed the presence of CXCR4 as well as CXCR7 and that cellular maturation in vivo and in vitro is accompanied by upregulation of CXCR7 and downregulation of CXCR4. Of note, in the diseased demyelinating central nervous system, CXCR7 expression is maintained on oligodendroglial cells, whereas CXCR4 could not be detected. We then demonstrated that CXCL12 stimulation promotes morphological maturation of cultured primary oligodendrocyte precursor cells as well as their myelin expression. Pharmacological inhibition of the CXCR7 receptor was shown to block CXCL12-dependent effects entirely.

INTERPRETATION

Our findings suggest that a specific activation of the CXCR7 receptor could provide a means to promote oligodendroglial differentiation in the diseased or injured central nervous system.

Induction of myeloid-derived suppressor cells by tumor exosomes

Myeloid-derived suppressor cells (MDSCs) promote tumor progression. The mechanisms of MDSC development during tumor growth remain unknown. Tumor exosomes (T-exosomes) have been implicated to play a role in immune regulation, however the role of exosomes in the induction of MDSCs is unclear. Our previous work demonstrated that exosomes isolated from tumor cells are taken up by bone marrow myeloid cells. Here, we extend those findings showing that exosomes isolated from T-exosomes switch the differentiation pathway of these myeloid cells to the MDSC pathway (CD11b(+)Gr-1(+)). The resulting cells exhibit MDSC phenotypic and functional characteristics including promotion of tumor growth. Furthermore, we demonstrated that in vivo MDSC mediated promotion of tumor progression is dependent on T-exosome prostaglandin E2 (PGE2) and TGF-beta molecules. T-exosomes can induce the accumulation of MDSCs expressing Cox2, IL-6, VEGF, and arginase-1. Antibodies against exosomal PGE2 and TGF-beta block the activity of these exosomes on MDSC induction and therefore attenuate MDSC-mediated tumor-promoting ability. Exosomal PGE2 and TGF-beta are enriched in T-exosomes when compared with exosomes isolated from the supernatants of cultured tumor cells (C-exosomes). The tumor microenvironment has an effect on the potency of T-exosome mediated induction of MDSCs by regulating the sorting and the amount of exosomal PGE2 and TGF-beta available. Together, these findings lend themselves to developing specific targetable therapeutic strategies to reduce or eliminate MDSC-induced immunosuppression and hence enhance host antitumor immunotherapy efficacy.

CCR5 proinflammatory allele in prostate cancer risk: a pilot study in patients and centenarians from Sicily

Prostate cancer (PCa) is the most common malignant neoplasm in older men in Western countries. The number of affected older men is increasing. Therefore, strategies for prevention of prostate cancer are crucial. To this purpose it is essential to know the mechanisms involved in development and progression of this malignancy. Recently, an increasing body of genetic and epidemiological studies proposed new hypotheses for prostate carcinogenesis. It has been suggested that genetic factors as well as exposure to environmental factors such as infectious agents, dietary carcinogens, and hormonal imbalances participate in PCa development. Besides, chronic inflammation plays a key role in PCa. Taking into consideration this complex scenario, in the present study we evaluated whether CCR5Delta32 deletion of CCR5 gene might be associated with PCa susceptibility. For the control group we used centenarians, since they represent a disease-free human model. These preliminary results suggest that the CCR5Delta32 anti-inflammatory variant might be a resistance factor for the development of PCa.

CXCL14 is an autocrine growth factor for fibroblasts and acts as a multi-modal stimulator of prostate tumor growth

This study explored the role of secreted fibroblast-derived factors in prostate cancer growth. Analyses of matched normal and tumor tissue revealed up-regulation of CXCL14 in cancer-associated fibroblasts of a majority of prostate cancer. Fibroblasts over-expressing CXCL14 promoted the growth of prostate cancer xenografts, and increased tumor angiogenesis and macrophage infiltration. Mechanistic studies demonstrated that autocrine CXCL14-stimulation of fibroblasts stimulate migration and ERK-dependent proliferation of fibroblasts. CXCL14-stimulation of monocyte migration was also demonstrated. Furthermore, CXCL14-producing fibroblasts, but not recombinant CXCL14, enhanced in vitro proliferation and migration of prostate cancer cells and in vivo angiogenesis. These studies thus identify CXCL14 as a novel autocrine stimulator of fibroblast growth and migration, with multi-modal tumor-stimulatory activities. In more general terms, our findings suggest autocrine stimulation of fibroblasts as a previously unrecognized mechanism for chemokine-mediated stimulation of tumor growth, and suggest a novel mechanism whereby cancer-associated fibroblasts achieve their pro-tumorigenic phenotype.