Characterization, modes of interactions with DNA/BSA biomolecules and anti-tumor activity of newly synthesized dinuclear platinum(II) complexes with pyridazine bridging ligand.

Platinum-based drugs are widely recognized efficient anti-tumor agents, but faced with multiple undesirable effects. Here, four dinuclear platinum(II) complexes, [{Pt(1,2-pn)Cl}2(µ-pydz)]Cl2 (C1), [{Pt(ibn)Cl}2(µ-pydz)]Cl2 (C2), [{Pt(1,3-pn)Cl}2(µ-pydz)]Cl2 (C3) and [{Pt(1,3-pnd)Cl}2(µ-pydz)]Cl2 (C4), were designed (pydz is pyridazine, 1,2-pn is ( ±)-1,2-propylenediamine, ibn is 1,2-diamino-2-methylpropane, 1,3-pn is 1,3-propylenediamine, and 1,3-pnd is 1,3-pentanediamine). Interactions and binding ability of C1-C4 complexes with calf thymus DNA (CT-DNA) has been monitored by viscosity measurements, UV-Vis, fluorescence emission spectroscopy and molecular docking. Binding affinities of C1-C4 complexes to the bovine serum albumin (BSA) has been monitored by fluorescence emission spectroscopy. The tested complexes exhibit variable cytotoxicity toward different mouse and human tumor cell lines. C2 shows the most potent cytotoxicity, especially against mouse (4T1) and human (MDA-MD468) breast cancer cells in the dose- and time-dependent manner. C2 induces 4T1 and MDA-MD468 cells apoptosis, further documented by the accumulation of cells at sub-G1 phase of cell cycle and increase of executive caspase 3 and caspase 9 levels in 4T1 cells. C2 exhibits anti-proliferative effect through the reduction of cyclin D3 and cyclin E expression and elevation of inhibitor p27 level. Also, C2 downregulates c-Myc and phosphorylated AKT, oncogenes involved in the control of tumor cell proliferation and death. In order to measure the amount of platinum(II) complexes taken up by the cells, the cellular platinum content were quantified. However, C2 failed to inhibit mouse breast cancer growth in vivo. Chemical modifications of tested platinum(II) complexes might be a valuable approach for the improvement of their anti-tumor activity, especially effects in vivo.

Influence of antipsychotics on metabolic syndrome risk in patients with schizophrenia.

Objective: Many studies so far have shown that antipsychotic therapy may have an effect on the development of metabolic syndrome in patients diagnosed with schizophrenia. Our goal was to determine whether our respondents are at risk for developing metabolic syndrome and who is more predisposed to it. Methods: In a stable phase, 60 patients diagnosed with schizophrenia were equally divided into three groups according to the drug (risperidone, clozapine, and aripiprazole monotherapy). Control group had 20 healthy examinees. Patients were evaluated first using The Positive and Negative Syndrome Scale (PANSS). Prolactin, lipid status, glycemia, insulin, cytokine values (IL-33, TGF-ß, and TNF-α) and C-reactive protein (CRP) were measured. Also, Body mass index (BMI), Homeostatic Model Assesment for Insulin Resistance (HOMA index), waist and hip circumference (WHR) and blood pressure (TA) measurement were performed in the study. Results: Patients treated with risperidone compared to healthy control subjects and aripiprazol group of patients had statistically significant difference in prolactin levels. In clozapine group compared to healthy control group values of HDL cholesterol and glucose level were statistically significant different. In aripiprazole group compared to healthy control group value of BMI was statistically significant different. Statistically significant correlations were found in TNF-α with glucose and HOMA index in risperidone treated patients and with BMI in clozapine group of patients; IL-33 with glucose in risperidone and with BMI in clozapine group of patients and TGF-ß with glucose in risperidone group, with insulin and HOMA index in clozapine group and statistically significant negative correlation with LDL cholesterol in aripiprazole group of patients. Conclusion: Patients on risperidone and clozapine therapy may be at greater risk of developing metabolic syndrome than patients treated with aripiprazole. Statistically significant difference in concentration of TNF-α and TGF-ß was in the group of patients treated with risperidone compared to healthy control group.

Contrasting Roles of the Galectin-3 in the Schizophrenia Onset, Clinical Presentation, and Somatic Comorbidity.

The role of the Galectin-3 (Gal-3) has already been explored in various somatic diseases, considering its engagement in infection, acute and chronic inflammation, and autoimmunity. Additionally, it has been recognized that Gal-3 is included in neuroinflammation and neurodegeneration, so we presented the possibility for its involvement in neuroprogression in schizophrenia. Gal-3 possibly participates in the early life programming of schizophrenia, also in the specific response to viral infections as a "second hit" later in life, and as a part of a unique systemic somatic dysfunction leading to the specific mental changes. In this review, we would like to put all these previous observations of Gal-3 properties in the context of schizophrenia onset, clinical symptoms presentation, frequent somatic comorbid states, and future options for Gal-3 centered treatment in schizophrenia.

Interleukin-33 pretreatment promotes metastatic growth of murine melanoma by reducing the cytotoxic capacity of CD8+ T cells and enhancing regulatory T cells.

Interleukin-33 (IL-33) regulates innate and acquired immune response to pathogens, self-antigens and tumors. IL-33 effects on tumors depend on the dose and mode of administration along with the type of malignancy. We studied the effects of IL-33 on the development of primary and metastatic melanoma induced by B16-F1 cell line in C57BL/6 mice. Intraperitoneally applied IL-33 restricts primary tumor growth. When administered intranasally 3 days prior to the intravenous injection of the tumor cells, IL-33 promoted growth of B16-F1 melanoma metastases, while B16-F10 gave massive metastases independently of IL-33. To mimic natural dissemination, we next used a limited number (5 × 104) of B16-F1 cells intravenously followed by application of IL-33 intraperitoneally. IL-33 increased the size of metastases (10.96 ± 3.96 mm2) when compared to the control group (0.86 ± 0.39 mm2), without changing incidence and number of metastases. IL-33 increased expression of ST2 on both tumor and immune cells in metastases. Also, IL-33 enhanced eosinophils and anti-tumor NK cells in the lung. The striking finding was reduced cytotoxicity of CD8+ T cells derived from metastatic lung of IL-33 injected mice. IL-33 reduced the percentage of TNF-α+ and IFN-γ+ CD8+ T cells while increasing the frequency of CD8+ T cells that express inhibitory molecules (PD-1, KLRG-1 and CTLA-4). There was a significant accumulation of CD11b+Gr-1+ myeloid suppressor cells and FoxP3+, IL-10+ and CTLA-4+ regulatory T cells in the metastatic lung of IL-33 injected mice. The relevance of IL-33 for melanoma metastases was also documented in a significantly increased level of serum IL-33 in stage III melanoma patients.

The Zn(S-pr-thiosal)2 complex attenuates murine breast cancer growth by inducing apoptosis and G1/S cell cycle arrest.

Aim: We investigated the antitumor effects of zinc(II) complex with S-propyl thiosalicylic acid [Zn(S-pr-thiosal)2] in 4T1 murine breast cancer model. Results: The Zn(S-pr-thiosal)2 complex reduced primary tumor growth in vivo and induced tumor cell apoptosis. The Zn(S-pr-thiosal)2 complex disrupted the balance between pro- and antiapoptotic Bcl-2 family members in 4T1 cells and induced G1/S cell cycle arrest. The Zn(S-pr-thiosal)2 complex increased the percentage of p16, p21 and p27 positive 4T1 cells. There was a significantly decrease in expression of STAT3 and its targets c-Myc and cyclin D3 in 4T1 cells treated with the Zn(S-pr-thiosal)2 complex thus contributing to G1/S cell cycle arrest and/or apoptosis. Conclusion: Our data suggest that the Zn(S-pr-thiosal)2 complex restricted tumor growth through induction of mitochondrial-driven apoptosis and suppression of cell cycle progression.

IL-33 receptor (ST2) deficiency downregulates myeloid precursors, inflammatory NK and dendritic cells in early phase of sepsis.

BACKGROUND: Sepsis is a life-threatening disease mediated by profound disturbances in systemic inflammatory response to infection. IL-33 is multifunctional regulator of numerous aspects of innate and adaptive immune response. The aim of this article was to further evaluate the role of IL-33 receptor (ST2) in different pathways of innate immunity during early polymicrobial sepsis. METHODS: Polymicrobial sepsis was induced using cecal ligation and puncture (CLP) model in ST2 deficient (ST2-/-) and wild type BALB/c mice. Peritoneal and spleen cells were isolated for further phenotyping. Apoptosis was determined by immunohistochemistry and flow cytometry. RESULTS: Deletion of ST2 leads to increased susceptibility to early manifestations of sepsis as evaluated by clinical signs and survival. These are accompanied by decrease in the total number of neutrophils, eosinophils and mast cells in peritoneal cavity 12 h after CLP. In early sepsis there was also low number of precursors of myeloid cells in particular CD11b+Ly6G+Ly6Clow cells in spleen of ST2-/- mice. Although the number of NK cells in the spleen was similar, there were significant differences in the presence of inflammatory IFN-γ and IL-17 producing NK cells. Further, ST2 deletion affects the phenotype and maturation of dendritic cell in sepsis. The total number of dendritic cells in the spleen was lower as well as IL-12 expressing dendritic cells. Finally, there was higher frequency of active caspase-3 positive and early apoptotic cells, in particular CD11c positive cells, in spleen of septic ST2-/- mice. CONCLUSION: Taken together, our data provide the evidence that ST2 deficiency in early phase of sepsis downregulates myeloid precursors, inflammatory NK and dendritic cells.

The organic ester O,O'-diethyl-(S,S)-ethylenediamine-N,N'-di-2-(3-cyclohexyl)propanoate dihydrochloride attenuates murine breast cancer growth and metastasis.

Pharmacological treatment of cancer is mostly limited by drug-toxicity and resistance. It has been noticed that new organic ester ligand, O,O'-diethyl-(S,S)-ethylenediamine-N,N'-di-2-(3-cyclohexyl)propanoate dihydrochloride (named DE-EDCP) showed effective cytotoxic capacities against several human and mouse cancer cell lines. However, its effects on tumor growth and metastasis are unexplored. The aim of present study was to examine the ability of DE-EDCP to inhibit 4T1 murine breast cancer growth and progression and to explore possible molecular mechanisms. DE-EDCP exhibited significant tumoricidal activity on human and murine breast cancer cell lines. Further, marked reduction of murine breast cancer growth and progression by DE-EDCP was shown. DE-EDCP exhibits fewer side-effects compared to cisplatin as a conventional chemotherapeutic. Results obtained from in vivo and in vitro experiments indicate that DE-EDCP induces apoptosis and inhibits proliferation of 4T1 cells. DE-EDCP increases percentage of 4T1 cells in late apoptosis, expression of pro-apoptotic Bax and caspase-3, while decreases expression of anti-apoptotic Bcl-2. DE-EDCP treatment increased the percentage of TUNEL-positive nuclei and reduced Ki-67 expression in breast cancer tissue. DE-EDCP decreased expression of cyclin D3 and Ki-67, increased expression of cyclin-dependent kinase inhibitors p16, p21 and p27 and arrested 4T1 cells in G0/G1 cell cycle phase. Expression of STAT3 and downstream regulated molecules, NANOG and SOX2, was reduced in 4T1 cells after DE-EDCP treatment. In conclusion, DE-EDCP impairs breast cancer growth and progression by triggering cancer cell death and inhibition of cancer cell proliferation. DE-EDCP might be of interest in the development of the new anticancer agent.

The Potential of Frog Skin-Derived Peptides for Development into Therapeutically-Valuable Immunomodulatory Agents.

The aim of this article is to review the immunoregulatory actions of frog skin-derived peptides in order to assess their potential as candidates for immunomodulatory or anti-inflammatory therapy. Frog skin peptides with demonstrable immunomodulatory properties have been isolated from skin secretions of a range of species belonging to the families Alytidae, Ascaphidae, Discoglossidae, Leptodactylidae, Pipidae and Ranidae. Their effects upon production of inflammatory and immunoregulatory cytokines by target cells have been evaluated ex vivo and effects upon cytokine expression and immune cell activity have been studied in vivo by flow cytometry after injection into mice. The naturally-occurring peptides and/or their synthetic analogues show complex and variable actions on the production of proinflammatory (TNF-α, IL-1ß, IL-12, IL-23, IL-8, IFN-γ and IL-17), pleiotropic (IL-4 and IL-6) and immunosuppressive (IL-10 and TGF-ß) cytokines by peripheral and spleen cells, peritoneal cells and/or isolated macrophages. The effects of frenatin 2.1S include enhancement of the activation state and homing capacity of Th1-type lymphocytes and NK cells in the mouse peritoneal cavity, as well as the promotion of their tumoricidal capacities. Overall, the diverse effects of frog skin-derived peptides on the immune system indicate their potential for development into therapeutic agents.

The frog skin host-defense peptide frenatin 2.1S enhances recruitment, activation and tumoricidal capacity of NK cells.

Frog skin is a source of peptides with various biological properties. Frenatin 2.1S, derived from norepinephrine-stimulated skin secretions of the Orinoco lime tree frog Sphaenorhynchus lacteus, exhibits immunostimulatory effects as demonstrated by the promotion of proinflammatory phenotypes of mononuclear cells in mouse peritoneal cavity and spleen. The aim of this study was to identify the populations of host cells sensitive to the action of frenatin 2.1S in vivo and to study its effects on their functional antitumor capacity. A single injection of frenatin 2.1S (100µg) in BALB/c mice increased the presence of peritoneal CD11c+ dendritic cells and CD3+ T cells 24h after administration and there was a significant increase in the number of IL-17 and CXCR3 expressing inflammatory T cells. Frenatin 2.1S treatment also increased the number of TNF-α expressing F4/80+ proinflammatory M1 macrophages. The most striking finding of the study is the marked increase of the number of peritoneal natural killer (NK) cells following frenatin 2.1S injection. Further, frenatin 2.1S administration led to activation of NK cells as evaluated by increased expression of NKG2D, FasL, CD69 and CD107a. The increased ratio of interferon-γ vs. IL-10 producing NK cells is further indication of the proinflammatory action of frenatin 2.1S. Peptide treatment enhanced the tumoricidal action of peritoneal NK cells on 4T1 mouse mammary carcinoma cells as revealed by the real-time automated monitoring of cell status. Our data demonstrate that frenatin 2.1S promotes activation and cytotoxic capacity of NK cells and should be regarded as a candidate for antitumor immunotherapy.

Angiogenic and lymphangiogenic profiles in histological variants of papillary thyroid carcinoma.

INTRODUCTION: Papillary thyroid carcinoma (PTC) is a well­differentiated tumor that occurs in several histological variants whose biological behaviors remain unclear. Angiogenesis and lymphangiogenesis are critical processes that enable tumor progression. OBJECTIVES: The aim of this study was to evaluate the angiogenic and lymphangiogenic phenotypes of PTC, considering the differences between histological variants. PATIENTS AND METHODS: Angiogenic and lymphangiogenic profiles were analyzed by determining microvascular density (MVD) and lymphatic vessel density (LVD) in 73 cases of PTC, using immunohistochemistry. To assess the biological markers involved in blood and lymph vessel formation, the expression of vascular endothelial growth factor (VEGF), cyclooxygenase 2 (COX­2), and p27kip1 (p27) was determined. RESULTS: MVD was significantly higher in patients with high­risk PTC and in those with local extrathyroidal and vascular invasion. Positive VEGF expression was strongly associated with high MVD and age­related tumor enlargement. The presence of lymph vessel invasion was associated with the expression of either VEGF or COX­2. The analysis of angiogenesis and lymphangiogenesis in different histological variants of PTC revealed elevated LVD rather than MVD in the follicular variant of PTC (FV­PTC).Lower MVD was observed in FV­PTC relative to the classic variant of PTC (CV­PTC). The frequency of VEGF­positive tumors was higher in CV­PTC than in FV­PTC. A significant association between COX­2 and p27 expression was observed in FV­PTC but not in CV­PTC. CONCLUSIONS: These results suggest that VEGF, COX­2, and p27 may be important biological markers that determine the angiogenic and lymphangiogenic potentials of PTC, particularly between the follicular and classic variants.

Circulating and tissue galectin-1 and galectin-3 in colorectal carcinoma: association with clinicopathological parameters, serum CEA, IL-17 and IL23.

PURPOSE: Galectins are modulators of many processes critical for tumor progression and metastasis but their clinical significance is still unclear. The objective of this study was to analyze the clinical significance of Galectin-1 and Galectin-3 in the tissue and sera of patients with colorectal carcinoma (CRC). Examined were also their association with serum CEA, IL-17 and IL-23 in CRC patients. METHODS: One hundred and twenty patients with CRC were included in this study. The expression of Galectin-1 and Galectin-3 in biopsy samples of CRC was determined using immunohistochemistry (N=120). The concentrations of Galectin-1, Galectin-3, IL-17 and IL-23 in the sera of CRC patients (N=38) were determined by Enzyme Linked Immunosorbent Assay (ELISA). RESULTS: Serum Galectin-1 concentrations positively correlated with parameters of malignancy including perineural invasion (p=0.016), lymph node involvement and distant metastases (p=0.029). Higher expression of peritumoral Galectin-1 was associated with both presence of perineural invasion and poor differentiation of CRC. Serum CEA levels positively correlated with circulating Galectin-1, but inversely correlated with peritumoral Galectin-1 expression. There was no correlation between Galectin-3 and clinicopathological parameters of CRC, but it was found that Galectin-3 expression in the tumor tissue positively correlated with serum IL-17 and IL-23. Circulating Galectin-3 levels significantly correlated with IL-17 (p=0.042), but not with IL-23 in the sera of CRC patients. CONCLUSIONS: This study suggests that Galectin-1 and Galectin-3 exhibit protumorigenic activity in CRC by affecting different aspects of tumor progression. Galectin-1 facilitates tumor invasion and metastasis while Galectin-3 preferentially modulates tumor-associated inflammatory processes.

In vivo administration of the frog skin peptide frenatin 2.1S induces immunostimulatory phenotypes of mouse mononuclear cells.

Host-defense peptides secreted by epithelial cells exhibit cytotoxic and immunoregulatory effects in order to protect the organism against invading microorganisms. Antimicrobial peptides derived from frog skin display both immunostimulatory and immunosuppressive actions as demonstrated by in vitro cytokine production by macrophages. Frenatin 2.1S, first isolated from skin secretions of the frog, Sphaenorhynchus lacteus (Hylidae), enhances the in vitro production of pro-inflammatory IL-1ß, TNF-α and IL-23 by mouse peritoneal cells. In order to test whether the immunostimulatory action of frenatin 2.1S may be reproduced in vivo, effects of intraperitoneal injections of this peptide on mononuclear cells in the peritoneum and spleen were determined 24h after administration. The data indicate that frenatin 2.1S enhances the activation state and homing capacity of Th1 type lymphocytes and NKT cells in the mouse peritoneal cavity, as evaluated by increased expression of early activation marker CD69 among T and NKT cells and chemokine receptor CXCR3 among T cells. Frenatin 2.1S significantly increases the percentage of (F4/80(+)CD11c(+)CD206(+)) pro-inflammatory M1 macrophages and enhances the expression of MHC class II molecules on F4/80(+)CD11c(+) macrophages in the mouse peritoneal cavity. Additionally, injection of frenatin 2.1S, in the presence or absence of lipopolysaccharide, increases the percentage of peritoneal B cells of the (CD19(+)CD11b(+)CD5(+)) B1a phenotype thus contributing to an inflammatory milieu. We suggest that the immunostimulatory effect of frenatin 2.1S may have therapeutic relevance in disease states, such as certain types of cancer, in which an enhanced inflammatory response may be beneficial.

Clinical significance of Cyclin D1, FGF3 and p21 protein expression in laryngeal squamous cell carcinoma.

PURPOSE: Laryngeal squamous cell carcinoma (LSCC) represents one of the most common cancers of the head and neck and the search for molecular markers is required for early diagnosis, prognosis and optimal therapy. The purpose of this study was to investigate the clinical significance of Cyclin D1, FGF3, p16 and p21 protein expression in LSCC and laryngeal dysplasia (LD) and to evaluate the associations between their expression levels and clinicopathological parameters of patients with LSCC. METHODS: Immunohistochemistry was employed to detect and quantify the expression levels of Cyclin D1, FGF3, p16 and p21 in the laryngeal tissues of 48 LSCC patients, 32 patients with LD and 28 subjects with healthy laryngeal mucosa (HLM). RESULTS: Significantly higher percentage of LSCC patients had positive Cyclin D1 expression compared with LD patients and HLM subjects (both p<0.01) and positive FGF3 expression than HLM subjects (p<0.05), while no differences in p16 and p21 positive expression were found among studied groups. The levels of Cyclin D1, FGF3 and p16 expression, as evaluated by immunostaining score, were significantly higher in patients with LSCC compared with LD and HLM groups (all p<0.05). Cyclin D1 proved to be highly sensitive and specific marker in differentiating LSCC from LD (sensitivity 81.2%, specificity 83.9%), while high sensitivity (81.2%) and lower specificity (41.4%) was observed in differentiating from HLM. Cyclin D1 and p21 expression levels were associated with regional lymph node metastases (both p<0.05) and Cyclin D1 expression levels significantly correlated with LSCC lymphatic invasion (x(2)=8.862; df=3; ?=0.031). CONCLUSIONS: Cyclin D1, FGF3 and p16 are overexpressed in patients with LSCC. Cyclin D1 is a highly sensitive marker in differentiating LSCC from LD or HLM. Cyclin D1 and p21 expression levels may be useful as predictive markers of metastases in LSCC.

Potential dual immunomodulatory role of VEGF in ulcerative colitis and colorectal carcinoma.

OBJECTIVE: Progression from ulcerative colitis (UC) toward colorectal carcinoma (CRC) is multistep process that includes gene alterations of tumor suppressor genes, such as p53 and p16. The aim of this study was to investigate the expression patterns of p16, p53 and VEGF in affected tissue and serum levels of cytokines TNF-α, IFN-γ, IL-4, IL-6, IL-10 and IL-17 in patients with UC and CRC, respectively. MATHERIALS AND METHODS. Serum levels of cytokine in patients with UC (n=24) and CRC (n=75) and in a healthy group (n=37) were analyzed by ELISA. Endoscopic biopsies specimens of UC and CRC were studied by immunohistochemical staining for p16, p53 and VEGF. RESULTS: Patients with UC with presence of extraintestinal manifestations, complications, and positive staining of p16, p53 and VEGF respectively had higher serum levels of pro-inflammatory cytokines. Higher percentage of CRC patients had positive staining of p16, p53 and VEGF. CRC patients with positive staining of VEGF had decreased systemic values of pro-inflammatory IFN-γ and increased values of immunosuppressive IL-10. CONCLUSIONS: Relatively low IL-10 in patients with severe UC is insufficient to compensate IL-6 secretion and subsequently enhanced type 1/17 immune response. In UC patients, p16 and p53 induce enhanced VEGF expression and subsequent production of pro-inflammatory TNF-α and IL-6. In CRC patients VEGF seems to have immunosuppressive role. It appears that tumor suppressor gene-VEGF axis have dual role on immune response in inflammation of UC and tumor growth and progression of CRC.

Interleukin-33/ST2 axis promotes breast cancer growth and metastases by facilitating intratumoral accumulation of immunosuppressive and innate lymphoid cells.

The role of IL-33/ST2 pathway in antitumor immunity is unclear. Using 4T1 breast cancer model we demonstrate time-dependent increase of endogenous IL-33 at both the mRNA and protein levels in primary tumors and metastatic lungs during cancer progression. Administration of IL-33 accelerated tumor growth and development of lung and liver metastases, which was associated with increased intratumoral accumulation of CD11b(+) Gr-1(+) TGF-ß1(+) myeloid-derived suppressor cells (MDSCs) that expressed IL-13α1R, IL-13-producing Lin(-) Sca-1(+) ST2(+) innate lymphoid cells (ILCs) and CD4(+) Foxp3(+) ST2(+) IL-10(+) Tregs compared to untreated mice. Higher incidence of monocytic vs. granulocytic MDSCs and plasmocytoid vs. conventional dendritic cells (DCs) was present in mammary tumors of IL-33-treated mice. Intratumoral NKp46(+) NKG2D(+) and NKp46(+) FasL(+) cells were markedly reduced after IL-33 treatment, while phosphate-buffered saline-treated ST2-deficient mice had increased frequencies of these tumoricidal natural killer (NK) cells compared to untreated wild-type mice. IL-33 promoted intratumoral cell proliferation and neovascularization, which was attenuated in the absence of ST2. Tumor-bearing mice given IL-33 had increased percentages of splenic MDSCs, Lin(-) Sca-1(+) ILCs, IL-10-expressing CD11c(+) DCs and alternatively activated M2 macrophages and higher circulating levels of IL-10 and IL-13. A significantly reduced NK cell, but not CD8(+) T-cell cytotoxicity in IL-33-treated mice was observed and the mammary tumor progression was not affected when CD8(+) T cells were in vivo depleted. We show a previously unrecognized role for IL-33 in promoting breast cancer progression through increased intratumoral accumulation of immunosuppressive cells and by diminishing innate antitumor immunity. Therefore, IL-33 may be considered as an important mediator in the regulation of breast cancer progression.

An analog of the host-defense peptide hymenochirin-1B with potent broad-spectrum activity against multidrug-resistant bacteria and immunomodulatory properties.

Hymenochirin-1B (IKLSPETKDN(10)LKKVLKGAIK(20)GAIAVAKMV.NH2) is a cationic, amphipathic, α-helical, host-defense peptide, first isolated from skin secretions of the Congo clawed frog Hymenochirus boettgeri (Pipidae). Structure-activity relationships were investigated by synthesizing analogs in which the Pro(5), Glu(6) and Asp(9) on the hydrophilic face of the α-helix are substituted by one or more l-lysine or d-lysine residues. Although replacement with l-lysine generates analogs with increased antimicrobial potency against a range of Gram-positive and Gram-negative bacteria (up to 8-fold), the peptides are more hemolytic. Increasing the cationicity of hymenochirin-1B while reducing the helicity by substitutions with d-lysine generates analogs that are between 2 and 8 fold more potent than the native peptide and are equally or less hemolytic. [E6k,D9k]hymenochirin-1B represents a candidate for drug development as it shows high potency against clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) and a range of Gram-negative bacteria, including multidrug-resistant strains of Acinetobacter baumannii and Stenotrophomonas maltophilia (MIC in the range 0.8-3.1 µM) and NDM-1 carbapenemase-producing clinical isolates of Klebsiella pneumoniae, Escherichia coli, Enterobacter cloacae and Citrobacter freundii (MIC in the range 3.1-6.25 µM), and low hemolytic activity (LC50=302 µM). [E6k,D9k]hymenochirin-1B, at a concentration of 2.5 µM, significantly (P<0.05) stimulates the production of the anti-inflammatory cytokines IL-4 and IL-10 by human peripheral blood mononuclear cells but is without significant effect on production of the pro-inflammatory cytokines TNF-α and IL-17.

Galectin-3 is a regulator of metaflammation in adipose tissue and pancreatic islets.

The cells of the innate and adaptive immune systems have been implicated in the development of obesity-induced metaflammation and metabolic disorders including type 2 diabetes. Galectin-3, a ß-galactoside-binding lectin, modulates immune/inflammatory responses and specifically binds to advanced glycation end products (AGE), modified lipoproteins, and endotoxin. In the recently published study we demonstrate proinflammatory changes in the visceral adipose tissue and pancreatic islets in galectin-3-deficient mice fed high-fat diet which also exhibited excess adiposity, hyperglycemia, insulin resistance and systemic inflammation compared with their diet matched wild-type controls. This was associated with the increased incidence of Type-1 T and NKT cells and pro-inflammatory CD11c(+)CD11b(+) macrophages in the visceral adipose tissue. Severe insulitis, infiltration of macrophages expressing NLRP3 inflammasome and IL-1ß, and enhanced accumulation of AGE were present within the pancreatic islets in obese LGALS3(-/-) mice. Moreover, increased caspase-1 dependent IL-1ß secretion with increased expression of NLRP3 inflammasome and phospho-NFκBp65 were observed in LGALS3(-/-) peritoneal macrophages stimulated in vitro by lipopolysaccharide and/or saturated fatty acid palmitate. The amplified high-fat diet-induced obesity and hyperglycemia and exacerbated inflammation in adipose tissue and pancreatic islets in LGALS3(-/-) mice suggest an important role for galectin-3 in the regulation of adiposity, metaflammation and type 2 diabetes.

[The role of regulatory T cells in the modulation of anti-tumor immune response].

Regulatory T cells (Treg) represent a subset of CD4+T cells whose function is to suppress immune responses. Treg lymphocytes can be divided into two subsets: natural nTreg lymphocytes that are developed in the thymus and inducible iTreg lymphocytes, which originate from conventional T lymphocytes on the periphery.The majority of Treg lymphocytes express high levels of interleukin-2 (IL-2) receptor a chain (CD25) and transcription factor FoxP3 (critical for the development and suppressor activity of iTreg lymphocytes). Cancer cells can modulate anti-tumor immune response indirectly, through the activation of Treg lymphocytes. It has been shown that the loss of regulatory function by depletion of tumor-induced Treg lymphocytes may enhance effectors response, resulting in tumor rejection, while the increased number of Treg lymphocytes effectively prevents tumor destruction. nTreg lymphocytes express increasingly CTLA-4 and membrane-bound TGF-beta, which inhibits cytokine production and responses of effectors lymphocytes.iTreg lymphocytes secrete immunosuppressive cytokines such as ILreg-10 and TGF-beta.Treg lymphocytes represent one of important obstruction in anti-tumor immunity.

Galectin-3 deficiency accelerates high-fat diet-induced obesity and amplifies inflammation in adipose tissue and pancreatic islets.

Obesity-induced diabetes is associated with low-grade inflammation in adipose tissue and macrophage infiltration of islets. We show that ablation of galectin-3 (Gal-3), a galactoside-binding lectin, accelerates high-fat diet-induced obesity and diabetes. Obese LGALS3(-/-) mice have increased body weight, amount of total visceral adipose tissue (VAT), fasting blood glucose and insulin levels, homeostasis model assessment of insulin resistance, and markers of systemic inflammation compared with diet-matched wild-type (WT) animals. VAT of obese LGALS3(-/-) mice exhibited increased incidence of type 1 T and NKT lymphocytes and proinflammatory CD11c(+)CD11b(+) macrophages and decreased CD4(+)CD25(+)FoxP3(+) regulatory T cells and M2 macrophages. Pronounced mononuclear cell infiltrate, increased expression of NLRP3 inflammasome and interleukin-1ß (IL-1ß) in macrophages, and increased accumulation of advanced glycation end products (AGEs) and receptor for AGE (RAGE) expression were present in pancreatic islets of obese LGALS3(-/-) animals accompanied with elevated phosphorylated nuclear factor-κB (NF-κB) p65 and mature caspase-1 protein expression in pancreatic tissue and VAT. In vitro stimulation of LGALS3(-/-) peritoneal macrophages with lipopolysaccharide (LPS) and saturated fatty acid palmitate caused increased caspase-1-dependent IL-1ß production and increased phosphorylation of NF-κB p65 compared with WT cells. Transfection of LGALS3(-/-) macrophages with NLRP3 small interfering RNA attenuated IL-1ß production in response to palmitate and LPS plus palmitate. Obtained results suggest important protective roles for Gal-3 in obesity-induced inflammation and diabetes.

IL-33/ST2 axis in innate and acquired immunity to tumors.

Interleukin-33, a ligand for ST2/T1, has an important role in allergy, autoimmunity and inflammation. The role of IL-33/ST2 axis in cancer is not elucidated. Using metastatic breast cancer model we provide evidence that lack of ST2 signaling led to reduced tumor growth and metastasis and enhanced anti-tumor immunity.