105 research outputs found
Karst geomorphology of the “Canale di Pirro” polje, Apulia (Southern Italy).
In karst environment, a geomorphological map is a powerful instrument, which play a crucial role in understanding earth surface processes and landscape evolution. Furthermore, it could be very useful for speleological perspectives, natural resources exploitation and geo-hazards management (flood, sinkhole, subsidence, etc.), providing useful information that enhance the knowledge of the territory. In this work, we present a geomorphological map of the polje of “Canale di Pirro”, sited in the central part of Apulia Region, in Southern Italy, among the most interesting karst lands in the Mediterranean area. The map covers150km2withanelevationrangeof100-450ma.s.l.Thisareaisoneofthemostremarkablekarstlandforms in the region, characterized underground by a very interesting system of caves, that reaches the water table at a depth of -264 meters. The karst system, known as “Inghiottitoio di Masseria Rotolo”, following scuba-diving exploration below the watertable, has become with a depth of 324m, the deepest known cave in Apulia. The polje is bounded on both sides by tectonically-controlled ridges, showing an overall length of some 12 km. In ancient maps, dating back to the 16th century, the area is represented as crossed by a long river, called Cana. The map obtained derives from the integration of interpretation of aerial photographs, analysis of a digital elevation model and field surveys in order to obtain a correct distribution of landforms and fluvial processes, such as different varieties of karst depressions, conical hills, erosional gullies, alluvial fans and tectonic structures. It provides relevant information about the surface drainage processes, and for understanding, among other things, the groundwater circulation and the related recharge processes. This geomorphological map is part of a wider project, that combined geological, hydrogeological research and chemical analyses of the groundwater. It provides support to the ongoing studies of this part of Apulia region aimedto betterunderstand thegeological processes that originatedthe polje and its later evolution, and the related underground cave system. Further, it might also suggest possible improvements in land management and in the future choice of useful tools for the control of the quality and quantity of karst groundwater
Wnt3a neutralization enhances T-cell responses through indirect mechanisms and restrains tumor growth
The Wnt/beta-catenin pathway regulates T-cell functions, including the repression of effector functions to the advantage of memory development via Tcf1. In a companion study, we demonstrate that, in human cancers, Wnt3a/beta-catenin signaling maintains tumor-infiltrating T cells in a partially exhausted status. Here, we have investigated the effects of Wnt3a neutralization in vivo in a mouse tumor model. Abundant Wnt3a was released, mostly by stromal cells, in the tumor microenvironment. We tested whether Wnt3a neutralization in vivo could rescue the effector capacity of tumor-infiltrating T cells, by administering an antibody to Wnt3a to tumor-bearing mice. This therapy restrained tumor growth and favored the expansion of tumor antigen-specific CD8(+) effector memory T cells with increased expression of Tbet and IFN gamma and reduced expression of Tcf1. However, the effect was not attributable to the interruption of T-cell-intrinsic beta-catenin signaling, because Wnt3a/beta-catenin activation correlated with enhanced, not reduced, T-cell effector functions both ex vivo and in vitro. Adoptively transferred CD8(+) T cells, not directly exposed to the anti-Wnt3a antibody but infiltrating previously Wnt3a-neutralized tumors, also showed improved functions. The rescue of T-cell response was thus secondary to T-cell-extrinsic changes that likely involved dendritic cells. Indeed, tumor-derived Wnt3a strongly suppressed dendritic cell maturation in vitro, and anti-Wnt3a treatment rescued dendritic cell activities in vivo. Our results clarify the function of the Wnt3a/beta-catenin pathway in antitumor effector T cells and suggest that Wnt3a neutralization might be a promising immunotherapy for rescuing dendritic cell activities. (C) 2018 AACR
A Compact Solid State Detector for Small Angle Particle Tracking
MIDAS (MIcrostrip Detector Array System) is a compact silicon tracking
telescope for charged particles emitted at small angles in intermediate energy
photonuclear reactions. It was realized to increase the angular acceptance of
the DAPHNE detector and used in an experimental program to check the
Gerasimov-Drell-Hearn sum rule at the Mainz electron microtron, MAMI. MIDAS
provides a trigger for charged hadrons, p/pi identification and particle
tracking in the region 7 deg < theta < 16 deg. In this paper we present the
main characteristics of MIDAS and its measured performances.Comment: 13 pages (9 figures). Submitted to NIM
CD8+ T cells specific for cryptic apoptosis-associated epitopes exacerbate experimental autoimmune encephalomyelitis
The autoimmune immunopathology occurring in multiple sclerosis (MS) is sustained by myelin-specific and -nonspecific CD8(+) T cells. We have previously shown that, in MS, activated T cells undergoing apoptosis induce a CD8(+) T cell response directed against antigens that are unveiled during the apoptotic process, namely caspase-cleaved structural proteins such as non-muscle myosin and vimentin. Here, we have explored in vivo the development and the function of the immune responses to cryptic apoptosis-associated epitopes (AEs) in a well-established mouse model of MS, experimental autoimmune encephalomyelitis (EAE), through a combination of immunization approaches, multiparametric flow cytometry, and functional assays. First, we confirmed that this model recapitulated the main findings observed in MS patients, namely that apoptotic T cells and effector/memory AE-specific CD8(+) T cells accumulate in the central nervous system of mice with EAE, positively correlating with disease severity. Interestingly, we found that AE-specific CD8(+) T cells were present also in the lymphoid organs of unprimed mice, proliferated under peptide stimulation in vitro, but failed to respond to peptide immunization in vivo, suggesting a physiological control of this response. However, when mice were immunized with AEs along with EAE induction, AE-specific CD8(+) T cells with an effector/memory phenotype accumulated in the central nervous system, and the disease severity was exacerbated. In conclusion, we demonstrate that AE-specific autoimmunity may contribute to immunopathology in neuroinflammation
Regulatory T cells with multiple suppressive and potentially pro-tumor activities accumulate in human colorectal cancer
Tregs can contribute to tumor progression by suppressing antitumor immunity. Exceptionally, in human colorectal cancer (CRC), Tregs are thought to exert beneficial roles in controlling pro-tumor chronic inflammation. The goal of our study was to characterize CRC-infiltrating Tregs at multiple levels, by phenotypical, molecular and functional evaluation of Tregs from the tumor site, compared to non-tumoral mucosa and peripheral blood of CRC patients. The frequency of Tregs was higher in mucosa than in blood, and further significantly increased in tumor. Ex vivo, those Tregs suppressed the proliferation of tumor-infiltrating CD8(+) and CD4(+) T cells. A differential compartmentalization was detected between Helioshigh and Helios(low) Treg subsets (thymus-derived versus peripherally induced): while Helios(low) Tregs were enriched in both sites, only Helios(high) Tregs accumulated significantly and specifically in tumors, displayed a highly demethylated TSDR region and contained high proportions of cells expressing CD39 and OX40, markers of activation and suppression. Besides the suppression of T cells, Tregs may contribute to CRC progression also through releasing IL-17, or differentiating into Tfr cells that potentially antagonize a protective Tfh response, events that were both detected in tumor-associated Tregs. Overall, our data indicate that Treg accumulation may contribute through multiple mechanisms to CRC establishment and progression
ISG15 protects human Tregs from interferon alpha-induced contraction in a cell-intrinsic fashion
Objectives: Type I interferons (IFNs) inhibit regulatory T-cell (Treg) expansion and activation, making them beneficial in antiviral responses, but detrimental in autoimmune diseases. Herein, we investigate the role of ISG15 in human Tregs in the context of refractoriness to type I IFN stimulation. Methods: ISG15 expression and Treg dynamics were analysed in vitro and ex vivo from patients with chronic hepatitis C, with lupus and ISG15 deficiency. Results: ISG15 is expressed at high levels in human Tregs, renders them refractory to the IFN-STAT1 signal, and protects them from IFN-driven contraction. In vitro, Tregs from healthy controls upregulate ISG15 upon activation to higher levels than conventional CD4 T cells, and ISG15-silenced Tregs are more susceptible to IFNα-induced contraction. In human ISG15 deficiency, patient Tregs display an elevated IFN signature relative to Tregs from healthy control. In vivo, in patients with chronic hepatitis C, 2 days after starting pegIFN/ribavirin therapy, a stronger ISG15 inducibility correlates with a milder Treg depletion. Ex vivo, in systemic lupus erythematosus patients, higher levels of ISG15 are associated to reduced STAT1 phosphorylation in response to IFNα, and also to increased frequencies of Tregs, characterising active disease. Conclusion: Our results reveal a Treg-intrinsic role of ISG15 in dictating their refractoriness to the IFN signal, thus preserving the Treg population under inflammatory conditions
Combination of chemotherapy and PD-1 blockade induces T cell responses to tumor non-mutated neoantigens
Grimaldi and Cammarata et al. develop a proteomics-based, target discovery platform to identify immunogenic proteins specific to apoptotic tumor cells. This study highlights the importance of protein modifications in apoptotic tumor cells as a mechanism of generating immunogenic neoantigens that can be targeted for T cell-based immunotherapy.Here, we developed an unbiased, functional target-discovery platform to identify immunogenic proteins from primary non-small cell lung cancer (NSCLC) cells that had been induced to apoptosis by cisplatin (CDDP) treatment in vitro, as compared with their live counterparts. Among the multitude of proteins identified, some of them were represented as fragmented proteins in apoptotic tumor cells, and acted as non-mutated neoantigens (NM-neoAgs). Indeed, only the fragmented proteins elicited effective multi-specific CD4(+) and CD8(+) T cell responses, upon a chemotherapy protocol including CDDP. Importantly, these responses further increased upon anti-PD-1 therapy, and correlated with patients' survival and decreased PD-1 expression. Cross-presentation assays showed that NM-neoAgs were unveiled in apoptotic tumor cells as the result of caspase-dependent proteolytic activity of cellular proteins. Our study demonstrates that apoptotic tumor cells generate a repertoire of immunogenic NM-neoAgs that could be potentially used for developing effective T cell-based immunotherapy across multiple cancer patients
Polyfunctional Type-1, -2, and -17 CD8+ T Cell Responses to Apoptotic Self-Antigens Correlate with the Chronic Evolution of Hepatitis C Virus Infection
Caspase-dependent cleavage of antigens associated with apoptotic cells plays a prominent role in the generation of CD8+ T cell responses in various infectious diseases. We found that the emergence of a large population of autoreactive CD8+ T effector cells specific for apoptotic T cell-associated self-epitopes exceeds the antiviral responses in patients with acute hepatitis C virus infection. Importantly, they endow mixed polyfunctional type-1, type-2 and type-17 responses and correlate with the chronic progression of infection. This evolution is related to the selection of autoreactive CD8+ T cells with higher T cell receptor avidity, whereas those with lower avidity undergo prompt contraction in patients who clear infection. These findings demonstrate a previously undescribed strict link between the emergence of high frequencies of mixed autoreactive CD8+ T cells producing a broad array of cytokines (IFN-γ, IL-17, IL-4, IL-2…) and the progression toward chronic disease in a human model of acute infection
Transport of Po Valley aerosol pollution to the northwestern Alps – Part 1: Phenomenology
Mountainous regions are often considered pristine environments;
however they can be affected by pollutants emitted in more populated and
industrialised areas, transported by regional winds. Based on experimental
evidence, further supported by modelling tools, here we demonstrate and quantify
the impact of air masses transported from the Po Valley, a European
atmospheric pollution hotspot, to the northwestern Alps. This is achieved
through a detailed investigation of the phenomenology of near-range (a few
hundred kilometres), trans-regional transport, exploiting synergies of
multi-sensor observations mainly focussed on particulate matter. The explored
dataset includes vertically resolved data from atmospheric profiling
techniques (automated lidar ceilometers, ALCs), vertically integrated aerosol
properties from ground (sun photometer) and space, and in situ measurements
(PM10 and PM2.5, relevant chemical analyses, and aerosol
size distribution). During the frequent advection episodes from the Po basin,
all the physical quantities observed by the instrumental setup are found to
significantly increase: the scattering ratio from ALC reaches values >30,
aerosol optical depth (AOD) triples, surface PM10 reaches
concentrations >100 µg m−3 even in rural areas, and
contributions to PM10 by secondary inorganic compounds such as
nitrate, ammonium, and sulfate increase up to 28 %, 8 %, and 17 %,
respectively. Results also indicate that the aerosol advected from the Po
Valley is hygroscopic, smaller in size, and less light-absorbing compared to
the aerosol type locally emitted in the northwestern Italian Alps. In this
work, the phenomenon is exemplified through detailed analysis and discussion
of three case studies, selected for their clarity and relevance within the
wider dataset, the latter being fully exploited in a companion paper
quantifying the impact of this phenomenology over the long-term
(Diémoz et al., 2019). For the three case studies investigated, a high-resolution
numerical weather prediction model (COSMO) and a Lagrangian tool (LAGRANTO)
are employed to understand the meteorological mechanisms favouring
transport and to demonstrate the Po Valley origin of the air masses. In
addition, a chemical transport model (FARM) is used to further support the
observations and to partition the contributions of local and non-local
sources. Results show that the simulations are important to the understanding
of the phenomenon under investigation. However, in quantitative terms,
modelled PM10 concentrations are 4–5 times lower than the ones
retrieved from the ALC and maxima are anticipated in time by 6–7 h.
Underestimated concentrations are likely mainly due to deficiencies in the
emission inventory and to water uptake of the advected particles not fully
reproduced by FARM, while timing mismatches are likely an effect of
suboptimal simulation of up-valley and down-valley winds by COSMO. The
advected aerosol is shown to remarkably degrade the air quality of the Alpine
region, with potential negative effects on human health, climate, and
ecosystems, as well as on the touristic development of the investigated area.
The findings of the present study could also help design mitigation
strategies at the trans-regional scale in the Po basin and suggest an
observation-based approach to evaluate the outcome of their implementation.</p
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