891 research outputs found
Tumor-derived microvesicles modulate antigen cross-processing via reactive oxygen species-mediated alkalinization of phagosomal compartment in dendritic cells
Dendritic cells (DCs) are the only antigen-presenting cells able to prime naĂŻve T cells and
cross-prime antigen-specific CD8+ T cells. Their functionality is a requirement for the
induction and maintenance of long-lasting cancer immunity. Albeit intensively investigated,
the in vivo mechanisms underlying efficient antigen cross-processing and presentation
are not fully understood. Several pieces of evidence indicate that antigen transfer to DCs
mediated by microvesicles (MVs) enhances antigen immunogenicity. This mechanism
is also relevant for cross-presentation of those tumor-associated glycoproteins such as
MUC1 that are blocked in HLA class II compartment when internalized by DCs as soluble
molecules. Here, we present pieces of evidence that the internalization of tumor-derived
MVs modulates antigen-processing machinery of DCs. Employing MVs derived from
ovarian cancer ascites fluid and established tumor cell lines, we show that MV uptake
modifies DC phagosomal microenvironment, triggering reactive oxygen species (ROS)
accumulation and early alkalinization. Indeed, tumor MVs carry radical species and the
MV uptake by DCs counteracts the chemically mediated acidification of the phagosomal
compartment. Further pieces of evidence suggest that efficacious antigen cross-priming
of the MUC1 antigen carried by the tumor MVs results from the early signaling induced by
MV internalization and the function of the antigen-processing machinery of DCs. These
results strongly support the hypothesis that tumor-derived MVs impact antigen immunogenicity
by tuning the antigen-processing machinery of DCs, besides being carrier of
tumor antigens. Furthermore, these findings have important implications for the exploitation
of MVs as antigenic cell-free immunogen for DC-based therapeutic strategies
Association Between Mannose-bindingLectin Gene Polymorphisms and Necrotizing Enterocolitis in Preterm Infants.
Investigation of Ni@CoO core-shell nanoparticle films synthesized by sequential layer deposition
Films of Ni@CoO core-shell nanoparticles (NP Ni core size d â 11 nm) have been grown on Si/SiOx and lacey carbon supports, by a sequential layer deposition method: a first layer of CoO was evaporated on the substrate, followed by the deposition of a layer of pre-formed, mass-selected Ni NPs, and finally an overlayer of CoO was added. The Ni NPs were formed by a magnetron gas aggregation source, and mass selected with a quadrupole mass filter. The morphology of the films was investigated with Scanning Electron Microscopy and Scanning Transmission Electron Microscopy. The Ni NP cores have a shape compatible with McKay icosahedron, caused by multitwinning occurring during their growth in the source, and the Ni NP layer shows the typical random paving growth mode. After the deposition of the CoO overlayer, CoO islands are observed, gradually extending and tending to merge with each other, with the formation of shells that enclose the Ni NP cores. In situ X-ray Photoelectron Spectroscopy showed that a few Ni atomic layers localized at the core-shell interface are oxidized, hinting at the possibility of creating an intermediate NiO shell between Ni and CoO, depending on the deposition conditions. Finally, X-ray Magnetic Circular Dichroism at the Ni L2,3 absorption edge showed the presence of magnetization at room temperature even at remanence, revealing the possibility of magnetic stabilization of the NP film
Monoclonal Antibodies in Gynecological Cancer: A Critical Point of View
During the last decades, several improvements in treating gynecological malignancies have been achieved. In particular, target therapies, mostly monoclonal antibodies, have emerged as an attractive option for the treatment of these malignancies. In fact, various molecular-targeted agents have been developed for a variety of malignancies with the objective to interfere with a precise tumor associated receptor, essential for cancer cell survival or proliferation, blocking its function, of the cancer cells. Alternatively, monoclonal antibodies have been developed to block immune suppression or enhance functions of immune effector cells. So far, several monoclonal antibodies have been tested for clinical efficacy for the treatment of gynecological cancers. Antibodies against Vascular Endothelial Growth Factor (VEGF) and Epidermal Growth Factor Receptor (EGFR) have been used in different neoplasms such as ovarian and cervical cancer. Catumazumab, a bivalent antibody against CD3 and EpCAM, is effective in the treatment of neoplastic ascites. Other antibodies are peculiar for specific cancer-associated antigen such as Oregovomab against CA125 or Farletuzumab against the folate receptor. Here we describe the preclinical and clinical experience gained up to now with monoclonal antibodies in tumors of the female genital tract and trace future therapeutic and research venues
IDO1 involvement in mTOR pathway: A molecular mechanism of resistance to mTOR targeting in medulloblastoma
Medulloblastoma (MB) is the most common malignant brain tumor in children. Despite therapeutic advancements, high-risk groups still present significant mortality. A deeper knowledge of the signaling pathways contributing to MB formation and aggressiveness would help develop new successful therapies. The target of rapamycin, mTOR signaling, is known to be involved in MB and is already targetable in the clinical setting. Furthermore, mTOR is a master metabolic regulator able to control cell growth versus autophagy decisions in conditions of amino-acid deprivation that can be due to IDO1 enzymatic activity. IDO1 has been also implicated in the regulation of inflammation, as well as of T cell-mediated immune responses, in a variety of pathological conditions, including brain tumors. In particular, IDO1 induces expansion of regulatory T-cells (Treg), preventing immune response against tumor cells. Analysis of 27 MB tissue specimens for the expression of both mTOR and IDO1 showed their widespread expression in all samples. Testing their cooperation in vitro, a significant involvement of IDO1 in mTOR immunogenic pathway was found, able to counteract the aim of rapamycin treatment. In MB cell lines, inhibition of mTOR strongly induced IDO1 expression and activity, corroborating its ability to recruit Treg cells in the tumor microenvironment. The mTOR/IDO1 cross talk was found to be strictly specific of MB cells. We demonstrated that mTOR pathway cross talks with IDO1 pathway to promote MB immune escape, possibly contributing to failure of mTOR- targeted therapy
International Postgraduate Course: Summer Stroke School. Healthy Lifestyle and Prevention of Stroke
Selected cohort characteristics. Comparison of baseline characteristics between included and excluded study participants. (DOCX 13 kb
Role of KamutÂź brand khorasan wheat in the counteraction of non-celiac wheat sensitivity and oxidative damage
It has been suggested that ancient grains show lower immunogenic properties and therefore can be introduced in the diet of non-celiac wheat-sensitive people. In the present study we investigated the possible difference in inflammation caused by feeding ancient KamutÂź wheat pasta (KP) compared to modern durum wheat pasta (WP) to rats. The effect of the two experimental diets on the oxidative status was also compared in basal condition and after an exogenous oxidative stress. In rats fed WP the histological evaluation of the duodenum morphology evidenced a flattened mucosa, an unusual shape and shortening of the villi, and a high lymphocyte infiltration, while no modifications were detected in KP fed animals. The fecal metabolite profiling was differently modified by the two diets, suggesting significant changes in the gut microflora. Furthermore, the results confirmed previous data on the antioxidant protection in rats by KamutÂź wheat foods. It is conceivable that KamutÂź components can act through a hormetic effect, eliciting an adaptive response that protects the organism against both oxidative stress and inflammatio
Evaluation of Endoglin (CD105) expression in pediatric rhabdomyosarcoma
BACKGROUND: The Intratumoral Microvessel Density (IMVD) is commonly used to quantify tumoral vascularization and is usually assessed by pan-endothelial markers, such as CD31. Endoglin (CD105) is a protein predominantly expressed in proliferating endothelium and the IMVD determined by this marker measures specifically the neovascularization. In this study, we investigated the CD105 expression in pediatric rhabdomyosarcoma and assessed the neovascularization by using the angiogenic ratio IMVD-CD105 to IMVD-CD31. METHODS: Paraffin-embedded archival tumor specimens were selected from 65 pediatric patients affected by rhabdomyosarcoma. The expression levels of CD105, CD31 and Vascular Endothelial Growth Factor (VEGF) were investigated in 30 cases (18 embryonal and 12 alveolar) available for this study. The IMVD-CD105 to IMVD-CD31 expression ratio was correlated with clinical and pathologic features of these patients. RESULTS: We found a specific expression of endoglin (CD105) in endothelial cells of all the rhabdomyosarcoma specimens analyzed. We observed a significant positive correlation between the IMVD individually measured by CD105 and CD31. The CD105/CD31 expression ratio was significantly higher in patients with lower survival and embryonal histology. Indeed, patients with a CD105/CD31 expression ratioâ<â1.3 had a significantly increased OS (88%, 95%CI, 60%-97%) compared to patients with higher values (40%, 95%CI, 12%-67%). We did not find any statistical correlation among VEGF and EFS, OS and CD105/CD31 expression ratio. CONCLUSION: CD105 is expressed on endothelial cells of rhabdomyosarcoma and represent a useful tool to quantify neovascularization in this tumor. If confirmed by further studies, these results will indicate that CD105 is a potential target for combined therapies in rhabdomyosarcoma.We thank Professor Franco Locatelli for critical reading this paper and for his
suggestions. We would also like to thank the children
â
s parents, who gave
their informed consent for publication and
âIl cuore grande di Flavio
âOnlus.
Dr. Marta Colletti is a post-doctoral fellow of the Umberto Veronesi Founda-
tion. To Valentina Polcini for proofreading.S
Modeling macroalgal forest distribution at Mediterranean scale : present status, drivers of changes and insights for conservation and management
Macroalgal forests are one of the most productive and valuable marine ecosystems, but yet strongly exposed to fragmentation and loss. Detailed large-scale information on their distribution is largely lacking, hindering conservation initiatives. In this study, a systematic effort to combine spatial data on Cystoseira C. Agardh canopies (Fucales, Phaeophyta) was carried out to develop a Habitat Suitability Model (HSM) at Mediterranean scale, providing critical tools to improve site prioritization for their management, restoration and protection. A georeferenced database on the occurrence of 20 Cystoseira species was produced collecting all the available information from published and grey literature, web data portals and co-authors personal data. Data were associated to 55 predictor variable layers in the (ASCII) raster format and were used in order to develop the HSM by means of a Random Forest, a very effective Machine Learning technique. Knowledge about the distribution of Cystoseira canopies was available for about the 14% of the Mediterranean coastline. Absence data were available only for the 2% of the basin. Despite these gaps, our HSM showed high accuracy levels in reproducing Cystoseira distribution so that the first continuous maps of the habitat across the entire basin was produced. Misclassification errors mainly occurred in the eastern and southern part of the basin, where large gaps of knowledge emerged. The most relevant drivers were the geomorphological ones, followed by anthropogenic variables proxies of pollution and urbanization. Our model shows the importance of data sharing to combine a large number of spatial and environmental data, allowing to individuate areas with high probability of Cystoseira occurrence as suitable for its presence. This approach encourages the use of this modeling tool for the prediction of Cystoseira distribution and for supporting and planning conservation and management initiatives. The step forward is to refine the spatial information of presence-absence data about Cystoseira canopies and of environmental predictors in order to address species-specific assessments.peer-reviewe
Pointing in cervical dystonia patients
IntroductionThe normal hemispheric balance can be altered by the asymmetric sensorimotor signal elicited by Cervical Dystonia (CD), leading to motor and cognitive deficits.MethodsDirectional errors, peak velocities, movement and reaction times of pointing towards out-of-reach targets in the horizontal plane were analysed in 18 CD patients and in 11 aged-matched healthy controls.ResultsCD patients displayed a larger scatter of individual trials around the average pointing direction (variable error) than normal subjects, whatever the arm used, and the target pointed. When pointing in the left hemispace, all subjects showed a left deviation (constant error) with respect to the target position, which was significantly larger in CD patients than controls, whatever the direction of the abnormal neck torsion could be. Reaction times were larger and peak velocities lower in CD patients than controls.DiscussionDeficits in the pointing precision of CD patients may arise from a disruption of motor commands related to the sensorimotor imbalance, from a subtle increase in shoulder rigidity or from a reduced agonists activation. Their larger left bias in pointing to left targets could be due to an increased right parietal dominance, independently upon the direction of head roll/jaw rotation which expands the left space representation and/or increases left spatial attention. These deficits may potentially extend to tracking and gazing objects in the left hemispace, leading to reduced skills in spatial-dependent motor and cognitive performance
- âŠ