Abstract
Mast cells (MCs) are multifaceted innate immune cells often present in the tumor microenvironment (TME). Several recent findings support their contribution to the transition from chronic ...inflammation to cancer. However, MC-derived mediators can either favor tumor progression, inducing the spread of the tumor, or exert anti-tumorigenic functions, limiting tumor growth. This apparent controversial role likely depends on the plastic nature of MCs that under different microenvironmental stimuli can rapidly change their phenotype and functions. Thus, the exact effect of unique MC subset(s) during tumor progression is far from being understood. Using a murine model of colitis-associated colorectal cancer, we initially characterized the MC population within the TME and in non-lesional colonic areas, by multicolor flow cytometry and confocal microscopy. Our results demonstrated that tumor-associated MCs harbor a main connective tissue phenotype and release high amounts of Interleukin (IL)-6 and Tumor Necrosis Factor (TNF)-α. This MC phenotype correlates with the presence of high levels of Stem Cell Factor (SCF) and IL-33 inside the tumor. Thus, we investigated the effect of SCF and IL-33 on primary MC cultures and underscored their ability to shape MC phenotype eliciting the production of pro-inflammatory cytokines. Our findings support the conclusion that during colonic transformation a sustained stimulation by SCF and IL-33 promotes the accumulation of a prevalent connective tissue-like MC subset that through the secretion of IL-6 and TNF-α maintains a pro-inflammatory microenvironment.
Nanoconjugated antibiotics can be regarded as next-generation drugs as they possess remarkable potential to overcome multidrug resistance in pathogenic bacteria. Iron oxide nanoparticles (IONPs) have ...been extensively used in the biomedical field because of their biocompatibility and magnetic properties. More recently, IONPs have been investigated as potential nanocarriers for antibiotics to be magnetically directed to/recovered from infection sites. Here, we conjugated the "last-resort" glycopeptide antibiotic teicoplanin to IONPs after surface functionalization with (3-aminopropyl) triethoxysilane (APTES). Classical microbiological methods and fluorescence and electron microscopy analysis were used to compare antimicrobial activity and surface interactions of naked IONPs, amino-functionalized NPs (NP-APTES), and nanoconjugated teicoplanin (NP-TEICO) with non-conjugated teicoplanin. As bacterial models, differently resistant strains of three Gram-positive bacteria (
,
, and
) and a Gram-negative representative (
) were used. The results indicated that teicoplanin conjugation conferred a valuable and prolonged antimicrobial activity to IONPs toward Gram-positive bacteria. No antimicrobial activity was detected using NP-TEICO toward the Gram-negative
Although IONPs and NP-APTES showed only insignificant antimicrobial activity in comparison to NP-TEICO, our data indicate that they might establish diverse interaction patterns at bacterial surfaces. Sensitivity of bacteria to NPs varied according to the surface provided by the bacteria and it was species specific. In addition, conjugation of teicoplanin improved the cytocompatibility of IONPs toward two human cell lines. Finally, NP-TEICO inhibited the formation of
biofilm, conserving the activity of non-conjugated teicoplanin versus planktonic cells and improving it toward adherent cells.
Several types of cancer grow differently depending on the environmental stimuli they receive. In glioma, exposure to an enriched environment (EE) increases the overall survival rate of tumor-bearing ...mice, acting on the cells that participate to define the tumor microenvironment. In particular, environmental cues increase the microglial production of interleukin (IL)-15 which promotes a pro-inflammatory (antitumor) phenotype of microglia and the cytotoxic activity of natural killer (NK) cells, counteracting glioma growth, thus representing a virtuous mechanism of interaction between NK cells and microglia. To mimic the effect of EE on glioma, we investigated the potential of creating engineered microglia as the source of IL-15 in glioma. We demonstrated that microglia modified with recombinant adeno-associated virus serotype 2 (rAAV2) carrying IL-15 (rAAV2-IL-15), to force the production of IL-15, are able to increase the NK cells viability in coculture. Furthermore, the intranasal delivery of rAAV2-IL-15 microglia triggered the interplay with NK cells
, enhancing NK cell recruitment and pro-inflammatory microglial phenotype in tumor mass of glioma-bearing mice, and ultimately counteracted tumor growth. This approach has a high potential for clinical translatability, highlighting the therapeutic efficacy of forced IL-15 production in microglia: the delivery of engineered rAAV2-IL-15 microglia to boost the immune response paves the way to design a new perspective therapy for glioma patients.
In the era of antimicrobial resistance, the use of nanoconjugated antibiotics is regarded as a promising approach for preventing and fighting infections caused by resistant bacteria, including those ...exacerbated by the formation of difficult-to-treat bacterial biofilms. Thanks to their biocompatibility and magnetic properties, iron oxide nanoparticles (IONPs) are particularly attractive as antibiotic carriers for the targeting therapy. IONPs can direct conjugated antibiotics to infection sites by the use of an external magnet, facilitating tissue penetration and disturbing biofilm formation. As a consequence of antibiotic localization, a decrease in its administration dosage might be possible, reducing the side effects to non-targeted organs and the risk of antibiotic resistance spread in the commensal microbiota. Here, we prepared nanoformulations of the 'last-resort' glycopeptides teicoplanin and vancomycin by conjugating them to IONPs
surface functionalization with (3-aminopropyl) triethoxysilane (APTES). These superparamagnetic NP-TEICO and NP-VANCO were chemically stable and NP-TEICO (better than NP-VANCO) conserved the typical spectrum of antimicrobial activity of glycopeptide antibiotics, being effective against a panel of staphylococci and enterococci, including clinical isolates and resistant strains. By a combination of different methodological approaches, we proved that NP-TEICO and, although to a lesser extent, NP-VANCO were effective in reducing biofilm formation by three methicillin-sensitive or resistant
strains. Moreover, when attracted and concentrated by the action of an external magnet, NP-TEICO exerted a localized inhibitory effect on
biofilm formation at low antibiotic concentration. Finally, we proved that the conjugation of glycopeptide antibiotics to IONPs reduced their intrinsic cytotoxicity toward a human cell line.
Herein we have analyzed chemokine involvement in the trafficking of developing and mature mouse natural killer (NK) cells in the bone marrow (BM). We observed drastic changes of CCR1, CXCR3, and ...CXCR4 expression and function during progression from precursor NK (pNK) cells to immature DX5− NK (iNK) and mature DX5+ NK (mNK) cells. pNK and mNK cells expressed the 3 receptors, while only CXCR4 was detected on iNK cells. Correspondingly, mNK cells migrated to CXCL12, CXCL10, and CCL3, and pNK and iNK cells to CXCL12, whereas pNK cells migrated to CCL3 and CXCL10 only after CXCL12 stimulation. Comparison of BM, peripheral blood, and spleen mNK cell populations revealed that CXCL12, CXCL10, and CCL3 preferentially affected BM mNK cell migration. Administration of the CXCR4 antagonist, AMD-3100, to C57BL/6 mice induced strong reduction of mNK and iNK cells in the BM and increased their number in blood and spleen. Conversely, CCL3 administration selectively mobilized mNK cells from the BM and this effect correlated with its ability to inhibit CXCL12-mediated mNK cell responses in vitro. Our results suggest that the combined action of chemokines selectively regulates localization of NK cell subsets in the BM and direct their maturation and migration to the periphery.
Glioblastoma is associated with a poor overall survival despite new treatment advances. Antiangiogenic strategies targeting VEGF based on tyrosine kinase inhibitors (TKIs) are currently undergoing ...extensive research for the treatment of glioma.Herein we demonstrated that the TKI axitinib induces DNA damage response (DDR) characterized by γ-H2AX phosphorylation and Chk1 kinase activation leading to G2/M cell cycle arrest and mitotic catastrophe in U87, T98 and U251 glioma cell lines. Moreover, we found that p21(Waf1/Cip1) increased levels correlates with induction of ROS and senescence-associated cell death in U87 and T98 cell lines, which are reverted by N-acetyl cysteine pretreatment. Conversely, U251 cell line showed a resistant phenotype in response to axitinib treatment, as evidenced by cell cycle arrest but no sign of cell death.The combinatorial use of axitinib with other therapies, with the aim of inhibiting multiple signaling pathways involved in tumor growth, can increase the efficiency of this TKI. Thus, we addressed the combined effects of axitinib with no toxic doses of the proteasome inhibitor bortezomib on the growth of U87 and T98 axitinib-sensitive and axitinib-resistant U251 cell lines. Compared to single treatments, combined exposure was more effective in inhibiting cell viability of all glioma cell lines, although with different cell death modalities. The regulation of key DDR and cell cycle proteins, including Chk1, γ-H2AX and p21(Waf1/Cip1) was also studied in glioma cell lines.Collectively, these findings provide new perspectives for the use of axitinib in combination with Bortezomib to overcome the therapy resistance in gliomas.
CCRL2 is a nonsignaling seven-transmembrane domain receptor. CCRL2 binds chemerin, a protein that promotes chemotaxis of leukocytes, including macrophages and natural killer (NK) cells. In addition, ...CCRL2 controls the inflammatory response in different pathologic settings, such as hypersensitivity, inflammatory arthritis, and experimental autoimmune encephalitis. Here, we investigated the role of CCRL2 in the regulation of lung cancer-related inflammation. The genetic deletion of
promoted tumor progression in urethane-induced and in
/
lung tumor mouse models. Similarly, a
-mutant lung tumor displayed enhanced growth in
-deficient mice. This phenotype was associated with a reduced inflammatory infiltrate characterized by the impaired recruitment of several leukocyte populations including NK cells. Bone marrow chimeras showed that CCRL2 expression by the nonhematopoietic cell compartment was responsible for the increased tumor formation observed in
-mutant
-deficient mice. In human and mouse lungs, CCRL2 was expressed by a fraction of CD31
endothelial cells, where it could control NK infiltration. Elevated CCRL2 expression in biopsies from human lung adenocarcinoma positively correlated with clinical outcome. These results provide evidence for a crucial role of CCRL2 in shaping an anti-lung tumor immune response.
The expression and regulation of oligopeptide transporter (PepT)-1 in relation to dietary treatments has not yet been explored in fish. In the present study, as part of our ongoing work on ...elucidating genes involved in compensatory growth induced by refeeding, we have now isolated a full-length cDNA representing the PepT1 in the European sea bass (
Dicentrarchus labrax). A total of 3014 bases including a 5′-untranslated region (101
bp), an open reading frame (ORF) (2184
bp), and a 3′-untranslated region (729
bp) were detected. The predicted 12 transmembrane domains of the protein (728 amino acids) are presented. A phylogenetic tree was constructed on the PepT1 sequences of sea bass and those of other teleost, avian, and mammalian species.
We also analyzed fasting- and refeeding-induced changes in the expression of PepT1 mRNA, using a one-tube two-temperature real-time RT-PCR with which the gene expression can be absolutely quantified using the standard curve method. Our results revealed that PepT1 was highly expressed in the proximal intestine with much lower levels of expression in the gill, brain, heart, liver and spleen. Nutritional status significantly influenced PepT1 mRNA copy number in the proximal intestine, inducing a down-regulation during prolonged fasting (35
days) and an up-regulation during the recovery from fasting. These findings offer new information about the dietary regulation of PepT1 mRNA level in sea bass, and support a role of this membrane transporter protein in promoting sea bass compensatory growth induced by refeeding.
This paper presents an investigation of the aerodynamic and aeroacoustic interaction of propellers for distributed electric propulsion applications. The rationale underlying the research is related ...to the key role that aeroacoustics plays in the establishment of the future commercial aviation scenario. The sustainable development of airborne transportation system is currently constrained by community noise, which limits the operations of existing airports and prevents the building of new ones. In addition, the substantial saturation of the existing noise abatement technologies inhibits the further development of the existing fleet, and imposes the adoption of disruptive configurations in terms of airframe layout and propulsion technology. Simulation-based data may help in clarifying many aspects related to the acoustic impact of such innovative concepts. Blended-wing-body equipped with distributed electric propulsion is one of the most promising, due to the beneficial effect of the substantial shielding induced by its geometry. Nevertheless, the novelty of the layout requires a thorough investigation of specific aspect for which no previous experience is available. Herein, the interaction between propellers is analysed for a fixed propeller geometry, as a function of their mutual distance and compared to the acoustic pattern of the isolated one. The aerodynamic results have been obtained using a boundary integral formulation for unsteady, incompressible, potential flows which accounts for the interaction between free wakes and propellers. For the aeroacoustic analyses, the Farassat 1A boundary integral formulation for the solution of the Ffowcs Williams and Hawkings equation has been used. These results provide an insight into the minimum distance between propellers to avoid aerodynamic/aeroacoustic interaction effects, which is an important starting point for the development of distributed propulsion systems.
The research presented here was conducted to ascertain the effectiveness of recovery technologies in remediating a compromised marine environment. The multidisciplinary approach aims to integrate ...traditional chemical-physical analysis and to assess the biological parameters of
Mytilus galloprovincialis
within different experimental mesocosms (W, G, and B). In particular, this system was designed to reproduce sediment resuspension in a marine environment, which is thought to be one cause of contaminant release. The study combined morphological and ultrastructural observations with DNA damage assessment and mRNA expression of those genes involved in cellular stress responses. The tissues of mussels maintained in the polluted mesocosm showed a higher accumulation of Pb and Hg than in those maintained in restored mesocosm. This observation correlates well with mRNA expression of
MT10
and data on DNA damage. The outcome of the biological evaluation consolidates the chemical characterization and supports the concept that the remediation method should be evaluated at an early stage, both to analytically determine the reduction of toxic components and to assess its ultimate impact on the biological system.
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