187 research outputs found

    On the eigenstate equivalent circuit for lossy asymmetric two-ports and its applications

    Get PDF
    An equivalent-circuit topology for two-port lossy non-symmetric reciprocal networks is presented [1]. The circuit topology is based on the eigenstate decomposition. The proposed circuit consists of two immittances and two transformers with a single complex turns ratio, as shown in Fig. 1. The only three complex parameters of the circuit are obtained from the eigenvalues and eigenvectors of the admittance or impedance matrix of the network in a straightforward way. The real parts of its immittances are always positive. Thus, the circuit is a powerful candidate for modeling asymmetric structures since it preserves some of the valuable properties of the symmetric lattice network: ability to separate the eigenstates and realizability of the real parts of the immittances. Indeed, it degenerates in the classic lattice network if the structure is symmetric. Two direct applications of the circuit are proposed. The first one is the design of asymmetric unit cells of leaky-wave antennas. A model can be found for the behavior of the two-port as a function of the degree of asymmetry using the proposed equivalent circuit topology. The new design methodology is simple and general, unlike the one proposed in [2]. The second application is the analysis and modeling of lossless and lossy bi-periodic scatterers [3]. It significantly simplifies their design, since it reduces the number of elements with respect to other equivalent circuits. Due to the capability of decomposition into the eigen excitations of the structure, the circuit provides an important physical insight. For different structures, the admittances have been successfully modeled using a few positive and frequency-independent RLC elements.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    PKC-omerga and HIV-1 transcriptional regulator Tat co-exist at the LTR promoter in CD4<sup>+</sup> T cells

    Get PDF
    PKCtheta is essential for the activation of CD4+ T cells. Upon TCR/CD28 stimulation, PKCtheta is phosphorylated and migrates to the immunological synapse, inducing the activation of cellular transcription factors such as NF-kB and kinases as ERK that are critical for HIV-1 replication. We previously demonstrated that PKCtheta is also necessary for HIV-1 replication but the precise mechanism is unknown. Efficient HIV-1 transcription and elongation is absolutely dependent on the synergy between NF-kB and the viral regulator Tat. Tat exerts its function by binding a RNA stem-loop structure proximal to the viral mRNA cap site termed TAR. Besides, due to its effect on cellular metabolic pathways, Tat causes profound changes in infected CD4+ T cells such as the activation of NF-kB and ERK. We hypothesized that the aberrant up-regulation of Tat-mediated activation of NF-kB and ERK occurred through PKCtheta signaling. In fact, Jurkat TetOff cells with stable and doxycycline-repressible expression of Tat (Jurkat-Tat) expressed high levels of mRNA for PKCtheta. In these cells, PKCtheta located at the plasma membrane was phosphorylated at T538 residue in undivided cells, in the absence of stimulation. Treatment with doxycycline inhibited PKCtheta phosphorylation in Jurkat-Tat, suggesting that Tat expression was directly related to the activation of PKCtheta. Both NF-kB and Ras/Raf/MEK/ERK signaling pathway were significantly activated in Jurkat-Tat cells, and this correlated with high transactivation of HIV-1 LTR promoter. RNA interference for PKCtheta inhibited NF-kB and ERK activity, as well as LTR-mediated transactivation even in the presence of Tat. In addition to Tat-mediated activation of PKCtheta in the cytosol, we demonstrated by sequential ChIP that Tat and PKCtheta coexisted in the same complex bound at the HIV-1 LTR promoter, specifically at the region containing TAR loop. In conclusion, PKCtheta-Tat interaction seemed to be essential for HIV-1 replication in CD4+ T cells and could be used as a therapeutic target

    Transcriptomic Evidence of the Immune Response Activation in Individuals With Limb Girdle Muscular Dystrophy Dominant 2 (LGMDD2) Contributes to Resistance to HIV-1 Infection

    Get PDF
    LGMDD2 is a rare form of muscular dystrophy characterized by one of the three heterozygous deletions described within the TNPO3 gene that result in the addition of a 15-amino acid tail in the C-terminus.TNPO3 is involved in the nuclear import of splicing factors and acts as a host cofactor for HIV-1 infection by mechanisms not yet deciphered. Further characterization of the crosstalk between HIV-1 infection and LGMDD2 disease may contribute to a better understanding of both the cellular alterations occurring in LGMDD2 patients and the role of TNPO3 in the HIV-1 cycle. To this regard, transcriptome profiling of PBMCs from LGMDD2 patients carrying the deletion c.2771delA in the TNPO3 gene was compared to healthy controls. A total of 545 differentially expressed genes were detected between LGMDD2 patients and healthy controls, with a high representation of G protein-coupled receptor binding chemokines and metallopeptidases among the most upregulated genes in LGMDD2 patients. Plasma levels of IFN-β and IFN-γ were 4.7- and 2.7-fold higher in LGMDD2 patients, respectively. An increase of 2.3-fold in the expression of the interferon-stimulated gene MxA was observed in activated PBMCs from LGMDD2 patients after ex vivo HIV-1 pseudovirus infection. Thus, the analysis suggests a pro-inflammatory state in LGMDD2 patients also described for other muscular dystrophies, that is characterized by the alteration of IL-17 signaling pathway and the consequent increase of metallopeptidases activity and TNF response. In summary, the increase in interferons and inflammatory mediators suggests an antiviral environment and resistance to HIV-1 infection but that could also impair muscular function in LGMDD2 patients, worsening disease evolution. Biomarkers of disease progression and therapeutic strategies based on these genes and mechanisms should be further investigated for this type of muscular dystrophy.This study was funded by Asociación Conquistando Escalones, French Agency for Research on AIDS and Viral Hepatitis (ANRS grant ECTZ107263), Instituto de Salud Carlos III (PI19CIII/00004), NIH grant R01AI143567, the Spanish Ministry of Science and Innovation (PID2019-110275RB I00) and Fundación Isabel Gemio. It has been conducted within the Spanish AIDS Research Network (RIS) and Centro de Investigación Biomédica en Red de Enfermedades Infecciosas, funded by Instituto de Salud Carlos 640 III (Plan Estatal de I+D+I 2013-2016) and co-funded by European Regional Development Fund (ERDF) “A way to build Europe” (RD16CIII/0002/0001).S

    Persistent Overactive Cytotoxic Immune Response in a Spanish Cohort of Individuals With Long-COVID: Identification of Diagnostic Biomarkers

    Get PDF
    Long-COVID is a new emerging syndrome worldwide that is characterized by the persistence of unresolved signs and symptoms of COVID-19 more than 4 weeks after the infection and even after more than 12 weeks. The underlying mechanisms for Long-COVID are still undefined, but a sustained inflammatory response caused by the persistence of SARS-CoV-2 in organ and tissue sanctuaries or resemblance with an autoimmune disease are within the most considered hypotheses. In this study, we analyzed the usefulness of several demographic, clinical, and immunological parameters as diagnostic biomarkers of Long-COVID in one cohort of Spanish individuals who presented signs and symptoms of this syndrome after 49 weeks post-infection, in comparison with individuals who recovered completely in the first 12 weeks after the infection. We determined that individuals with Long-COVID showed significantly increased levels of functional memory cells with high antiviral cytotoxic activity such as CD8+ TEMRA cells, CD8±TCRγδ+ cells, and NK cells with CD56+CD57+NKG2C+ phenotype. The persistence of these long-lasting cytotoxic populations was supported by enhanced levels of CD4+ Tregs and the expression of the exhaustion marker PD-1 on the surface of CD3+ T lymphocytes. With the use of these immune parameters and significant clinical features such as lethargy, pleuritic chest pain, and dermatological injuries, as well as demographic factors such as female gender and O+ blood type, a Random Forest algorithm predicted the assignment of the participants in the Long-COVID group with 100% accuracy. The definition of the most accurate diagnostic biomarkers could be helpful to detect the development of Long-COVID and to improve the clinical management of these patients.This work was supported by the Coordinated Research Activities at the National Center of Microbiology (CNM, Instituto de Salud Carlos III) (COV20_00679) to promote an integrated response against SARS-CoV-2 in Spain (Spanish Ministry of Science and Innovation), which is coordinated by Dr Inmaculada Casas (WHO National Influenza Center of the CNM); a generous donation provided by Chiesi España, S.A.U. (Barcelona, Spain); the Spanish Ministry of Science and Innovation (PID2019-110275RB-I00); and the Spanish AIDS Research Network RD16CIII/0002/0001 that is included in Acción Estratégica en Salud, Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica 2016-2020, Instituto de Salud Carlos III, European Region Development Fund (ERDF). The work of ML-H and SR-M is financed by NIH grant R01AI143567. The work of MT is supported by Instituto de Salud Carlos III (COV20_00679). The work of LV is supported by a pre-doctoral grant from Instituto de Salud Carlos III (FIS PI16CIII/00034-ISCIII-FEDER). The work of FR-M is financed by the Spanish Ministry of Science and Innovation (PID2019-110275RB-I00).S

    Tacrolimus CYP3A Single-Nucleotide Polymorphisms and Preformed T- and B-Cell Alloimmune Memory Improve Current Pretransplant Rejection-Risk Stratification in Kidney Transplantation

    Get PDF
    Rechazo agudo; Genética; InmunobiologíaRebuig agut; Genètica; ImmunobiologiaAcute rejection; Genetics; ImmunobiologyAchieving fast immunosuppression blood exposure after kidney transplantation is key to abrogating both preformed and de novo anti-donor humoral and cellular alloresponses. However, while tacrolimus (TAC) is the cornerstone immunosuppressant inhibiting adaptive alloimmunity, its blood exposure is directly impacted by different single-nucleotide polymorphisms (SNPs) in CYP3A TAC-metabolizing enzymes. Here, we investigated how functional TAC-CYP3A genetic variants (CYP3A4*22/CYP3A5*3) influence the main baseline clinical and immunological risk factors of biopsy-proven acute rejection (BPAR) by means of preformed donor-specific antibodies (DSAs) and donor-specific alloreactive T cells (DSTs) in a large European cohort of 447 kidney transplants receiving TAC-based immunosuppression. A total of 70 (15.7%) patients developed BPAR. Preformed DSAs and DSTs were observed in 12 (2.7%) and 227 (50.8%) patients, respectively. According to the different CYP3A4*22 and CYP3A5*3 functional allele variants, we found 4 differential new clusters impacting fasting TAC exposure after transplantation; 7 (1.6%) were classified as high metabolizers 1 (HM1), 71 (15.9%) as HM2, 324 (72.5%) as intermediate (IM), and 45 (10.1%) as poor metabolizers (PM1). HM1/2 showed significantly lower TAC trough levels and higher dose requirements than IM and PM (p < 0.001) and more frequently showed TAC underexposure (<5 ng/ml). Multivariate Cox regression analyses revealed that CYP3A HM1 and IM pharmacogenetic phenotypes (hazard ratio (HR) 12.566, 95% CI 1.99-79.36, p = 0.007, and HR 4.532, 95% CI 1.10-18.60, p = 0.036, respectively), preformed DSTs (HR 3.482, 95% CI 1.99-6.08, p < 0.001), DSAs (HR 4.421, 95% CI 1.63-11.98, p = 0.003), and delayed graft function (DGF) (HR 2.023, 95% CI 1.22-3.36, p = 0.006) independently predicted BPAR. Notably, a significant interaction between T-cell depletion and TAC underexposure was observed, showing a reduction of the BPAR risk (HR 0.264, 95% CI 0.08-0.92, p = 0.037). Such variables except for DSAs displayed a higher predictive risk for the development of T cell-mediated rejection (TCMR). Refinement of pretransplant monitoring by incorporating TAC CYP3A SNPs with preformed DSAs as well as DSTs may improve current rejection-risk stratification and help induction treatment decision-making.This work was supported by the Instituto de Salud Carlos III (ISCIII) (grant numbers PI16/01321, PI19/01710, and PI18/P1740) (co-funded by European Regional Development Fund, ERDF, a way to build Europe). Also, this work was partly supported by the SLT002/16/00183 grant, from the Department of Health of the Generalitat de Catalunya by the call “Acció instrumental de programes de recerca orientats en l’àmbit de la recerca i la innovació en salut.” The authors thank the Research Centers of Catalonia (CERCA) Programme/Generalitat de Catalunya for institutional support. OB was awarded an intensification grant from the “Instituto de Salud Carlos III” [NT19/00051]

    The Effect of Exclusive Olive Oil Consumption on Successful Aging: A Combined Analysis of the ATTICA and MEDIS Epidemiological Studies

    Get PDF
    The consumption of dietary fats, which occur naturally in various foods, poses important impacts on health. The aim of this study was to elucidate the association of exclusive use of olive oil for culinary purposes with successful aging in adults aged >50 years old and residing in Greece. Use of olive oil in food preparation and bio-clinical characteristics of the Greek participants enrolled in the ATTICA (n = 1128 adults from Athens metropolitan area) and the MEDiterranean Islands Study (MEDIS) (n = 2221 adults from various Greek islands and Mani) studies, were investigated in relation to successful aging (SA). Participants were divided into the following three categories: (a) no olive oil consumption; (b) combined consumption of olive oil and other dietary fats; and (c) exclusive olive oil consumption. The SA was measured using the previously validated successful aging index (SAI). After adjusting for age, sex, and smoking habits, combined consumption of olive oil and other fats (vs. no olive oil use) was not significantly associated with SAI levels (p = 0.114). However, exclusive olive oil intake (vs. no use of olive oil) was significantly associated with SAI (p = 0.001), particularly among those aged older than 70 years. Therefore, the exclusive consumption of olive oil, as opposed to either combined or no olive oil consumption, beneficially impacts successful aging, particularly among individuals over 70 years of age. Primary public health prevention strategies should seek to encourage the enhanced adoption of such dietary practices in order to promote healthy aging and longevity

    Recommendations by the Spanish Society of Epidemiology and Oral Public Health (SESPO) for the healthcare adaptation of public health dental clinics in Spain during the COVID-19 pandemic

    Get PDF
    In March 2020, the World Health Organization (WHO) declared the COVID-19 pandemic and, a few days later, the Spanish Government declared a State of Emergency and the population lockdown. This crisis situation crisis forced deep changes in health care. A

    The mutation of Transportin 3 gene that causes limb girdle muscular dystrophy 1F induces protection against HIV-1 infection

    Get PDF
    The causative mutation responsible for limb girdle muscular dystrophy 1F (LGMD1F) is one heterozygous single nucleotide deletion in the stop codon of the nuclear import factor Transportin 3 gene (TNPO3). This mutation causes a carboxy-terminal extension of 15 amino acids, producing a protein of unknown function (TNPO3_mut) that is co-expressed with wild-type TNPO3 (TNPO3_wt). TNPO3 has been involved in the nuclear transport of serine/arginine-rich proteins such as splicing factors and also in HIV-1 infection through interaction with the viral integrase and capsid. We analyzed the effect of TNPO3_mut on HIV-1 infection using PBMCs from patients with LGMD1F infected ex vivo. HIV-1 infection was drastically impaired in these cells and viral integration was reduced 16-fold. No significant effects on viral reverse transcription and episomal 2-LTR circles were observed suggesting that the integration of HIV-1 genome was restricted. This is the second genetic defect described after CCR5Δ32 that shows strong resistance against HIV-1 infection.This work was supported by crowfunding site PRECIPITA from FECYT, the MERCKSALUD Foundation, the Spanish Ministry of Science (FIS PI12/00969; PI16CIII/00034; SAF2016-78480-R); the Spanish AIDS Research Network RD16CIII/0002/0001 that is included in Acción Estratégica en Salud, Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica 2016-2020, Instituto de Salud Carlos III, European Region Development Fund (FEDER); CIBERer-ISCIII (FIS PI16/00316) co-financed by the European Regional Development Founds (FEDER), IIS La Fe (2016-0388; 2018-0200), and Fundación Isabel Gemio (http://www.fundacionisabelgemio.com). The work of Dra. Sara Rodríguez-Mora is supported by the Asociación Conquistando Escalones, funded by Spanish LGMD1F patients and Sara Borrell grant from Instituto de Salud Carlos III. The work of Dra. María Rosa López-Huertas is financed by ISCIII-Subdirección General de Evaluación and European Funding for Regional Development (FEDER) and by Spanish Ministry of Economy and Competitiveness (PIE13/00040). The work of Elena Mateos is supported by the Spanish Ministry of Economy and Competitiveness SAF2016-78480-R. The work of Lorena Vigón is supported by a pre-doctoral grant from Instituto de Salud Carlos III. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.S

    Surface Modified β-Ti-18Mo-6Nb-5Ta (wt%) Alloy for Bone Implant Applications : Composite Characterization and Cytocompatibility Assessment

    Get PDF
    Commercially available titanium alloys such as Ti-6Al-4V are established in clinical use as load-bearing bone implant materials. However, concerns about the toxic effects of vanadium and aluminum have prompted the development of Al- and V-free β-Ti alloys. Herein, a new alloy composed of non-toxic elements, namely Ti-18Mo-6Nb-5Ta (wt%), has been fabricated by arc melting. The resulting single β-phase alloy shows improved mechanical properties (Young's modulus and hardness) and similar corrosion behavior in simulated body fluid when compared with commercial Ti-6Al-4V. To increase the cell proliferation capability of the new biomaterial, the surface of Ti-18Mo-6Nb-5Ta was modified by electrodepositing calcium phosphate (CaP) ceramic layers. Coatings with a Ca/P ratio of 1.47 were obtained at pulse current densities, −j, of 1.8-8.2 mA/cm 2, followed by 48 h of NaOH post-treatment. The thickness of the coatings has been measured by scanning electron microscopy from an ion beam cut, resulting in an average thickness of about 5 μm. Finally, cytocompatibility and cell adhesion have been evaluated using the osteosarcoma cell line Saos-2, demonstrating good biocompatibility and enhanced cell proliferation on the CaP-modified Ti-18Mo-6Nb-5Ta material compared with the bare alloy, even outperforming their CaP-modified Ti-6-Al-4V counterparts

    A new regulatory mechanism of protein phosphatase 2A activity via SET in acute myeloid leukemia

    Get PDF
    Acute myeloid leukemia (AML) is an aggressive hematologic malignancy. Although novel emerging drugs are available, the overall prognosis remains poor and new therapeutic approaches are required. PP2A phosphatase is a key regulator of cell homeostasis and is recurrently inactivated in AML. The anticancer activity of several PP2A-activating drugs (e.g., FTY720) depends on their interaction with the SET oncoprotein, an endogenous PP2A inhibitor that is overexpressed in 30% of AML cases. Elucidation of SET regulatory mechanisms may therefore provide novel targeted therapies for SET-overexpressing AMLs. Here, we show that upregulation of protein kinase p38 beta is a common event in AML. We provide evidence that p38 beta potentiates SET-mediated PP2A inactivation by two mechanisms: facilitating SET cytoplasmic translocation through CK2 phosphorylation, and directly binding to and stabilizing the SET protein. We demonstrate the importance of this new regulatory mechanism in primary AML cells from patients and in zebrafish xenograft models. Accordingly, combination of the CK2 inhibitor CX-4945, which retains SET in the nucleus, and FTY720, which disrupts the SET-PP2A binding in the cytoplasm, significantly reduces the viability and migration of AML cells. In conclusion, we show that the p38 beta/CK2/SET axis represents a new potential therapeutic pathway in AML patients with SET-dependent PP2A inactivation
    corecore