Kaposi’s Sarcoma-Associated Herpesvirus-Encoded Viral IL-6 (vIL-6) Enhances Immunoglobulin Class-Switch Recombination

Kaposi’s sarcoma-associated herpesvirus (KSHV) is an oncogenic gamma-herpesvirus that causes AIDS-associated Kaposi sarcoma (KS) and several lymphoproliferative disorders. During the humoral immune response antigen-activated mature B cells acquire functional diversification by immunoglobulin heavy chain (IgH) class-switch recombination (CSR). CSR is initiated by activation-induced cytidine deaminase (AID) which targets highly repetitive switch (S)-regions to mediate DNA double-stranded breaks (DSBs) in the IgH locus facilitating intramolecular recombination. Here we show that in the context of cytokine stimulation, CSR is enhanced in murine B cells exposed only to replication-competent KSHV in an environment of KSHV infection, which coincided with elevated AID transcripts. Using murine splenic B cells and the mouse lymphoma CH12F3-2 CSR system, we identified that vIL-6, but not murine IL-6, increased class-switching, which correlated with upregulated AID expression. Together, these data suggest a regulatory role for KSHV vIL-6 in functionally modulating B cell biology by promoting CSR, which may in part explain how KSHV infection influences humoral immunity and affect KSHV pathogenesis

Prediction of stresses and strains around model tunnels with adjacent embedded walls in overconsolidated clay

This paper presents the results of finite element analyses carried out using different constitutive models for overconsolidated clay: the Modified Cam clay model and the Three-Surface Kinematic Hardening (3-SKH) model. These analyses are evaluated against data from an extensive series of physical model tests examining the influence of an embedded wall placed near a tunnel on ground movements and tunnel stability. It is shown that for heavily overconsolidated soils reasonable predictions of both deformations and failure can be obtained from kinematic hardening models such as the 3-SKH model, which allow plastic deformation inside a Modified Cam clay state boundary surface

Neutrophil-derived microvesicle induced dysfunction of brain microvascular endothelial cells in vitro

The blood-brain barrier (BBB), composed of brain microvascular endothelial cells (BMEC) that are tightly linked by tight junction (TJ) proteins, restricts the movement of molecules between the periphery and the central nervous system. Elevated systemic levels of neutrophils have been detected in patients with altered BBB function, but the role of neutrophils in BMEC dysfunction is unknown. Neutrophils are key players of the immune response and, when activated, produce neutrophil-derived microvesicles (NMV). NMV have been shown to impact the integrity of endothelial cells throughout the body and we hypothesize that NMV released from circulating neutrophils interact with BMEC and induce endothelial cell dysfunction. Therefore, the current study investigated the interaction of NMV with human BMEC and determined whether they altered gene expression and function in vitro. Using flow cytometry and confocal imaging, NMV were shown to be internalized by the human cerebral microvascular endothelial cell line hCMEC/D3 via a variety of energy-dependent mechanisms, including endocytosis and macropinocytosis. The internalization of NMV significantly altered the transcriptomic profile of hCMEC/D3, specifically inducing the dysregulation of genes associated with TJ, ubiquitin-mediated proteolysis and vesicular transport. Functional studies confirmed NMV significantly increased permeability and decreased the transendothelial electrical resistance (TEER) of a confluent monolayer of hCMEC/D3. These findings indicate that NMV interact with and affect gene expression of BMEC as well as impacting their integrity. We conclude that NMV may play an important role in modulating the permeability of BBB during an infection

KSHV-induced ligand mediated activation of PDGF receptor-alpha drives Kaposi's sarcomagenesis

Kaposi’s sarcoma (KS) herpesvirus (KSHV) causes KS, an angiogenic AIDS-associated spindle-cell neoplasm, by activating host oncogenic signaling cascades through autocrine and paracrine mechanisms. Tyrosine kinase receptor (RTK) proteomic arrays, identified PDGF receptor-alpha (PDGFRA) as the predominantly-activated RTK in KSHV-induced mouse KS-tumors. We show that: 1) KSHV lytic replication and the vGPCR can activate PDGFRA through upregulation of its ligands PDGFA/B, which increase c-myc, VEGF and KSHV gene expression in infected cells 2) KSHV infected spindle cells of most AIDS-KS lesions display robust phospho-PDGFRA staining 3) blocking PDGFRA-signaling with N-acetyl-cysteine, RTK-inhibitors Imatinib and Sunitinib, or dominant-negative PDGFRA inhibits tumorigenesis 4) PDGFRA D842V activating-mutation confers resistance to Imatinib in mouse-KS tumorigenesis. Our data show that KSHV usurps sarcomagenic PDGFRA signaling to drive KS. This and the fact that PDGFRA drives non-viral sarcomas highlights the importance for KSHV-induced ligand-mediated activation of PDGFRA in KS sarcomagenesis and shows that this oncogenic axis could be successfully blocked to impede KS tumor growth.Fil: Cavallin, Lucas E.. University of Miami; Estados UnidosFil: Ma, Qi. University of Miami; Estados UnidosFil: Naipauer, Julian. University of Miami; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Medicina Traslacional, Trasplante y Bioingeniería. Fundación Favaloro. Instituto de Medicina Traslacional, Trasplante y Bioingeniería; ArgentinaFil: Gupta, Sachin. University of Miami; Estados UnidosFil: Kurian, Mani. University of Miami; Estados UnidosFil: Locatelli, Paola. University of Miami; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Medicina Traslacional, Trasplante y Bioingeniería. Fundación Favaloro. Instituto de Medicina Traslacional, Trasplante y Bioingeniería; ArgentinaFil: Romanelli, Paolo. University of Miami; Estados UnidosFil: Nadji, Mehrdad. University of Miami; Estados UnidosFil: Goldschmidt Clermont, Pascal J.. University of Miami; Estados UnidosFil: Mesri, Enrique Alfredo. University of Miami; Estados Unido

A large-strain radial consolidation theory for soft clays improved by vertical drains

A system of vertical drains with combined vacuum and surcharge preloading is an effective solution for promoting radial flow, accelerating consolidation. However, when a mixture of soil and water is deposited at a low initial density, a significant amount of deformation or surface settlement occurs. Therefore, it is necessary to introduce large-strain theory, which has been widely used to manage dredged disposal sites in one-dimensional theory, into radial consolidation theory. A governing equation based on Gibson's large-strain theory and Barron's free-strain theory incorporating the radial and vertical flows, the weight of the soil, variable hydraulic conductivity and compressibility during the consolidation process is therefore presented

Kaposi's sarcoma herpesvirus activates the hypoxia response to usurp HIF2α-dependent translation initiation for replication and oncogenesis

Kaposi's sarcoma herpesvirus (KSHV) is an angiogenesis-inducing oncovirus whose ability to usurp the oxygen-sensing machinery is central to its oncogenicity. By upregulating the hypoxia-inducible factors (HIFs), KSHV reprograms infected cells to a hypoxia-like state, triggering angiogenesis. Here we identify a link between KSHV replicative biology and oncogenicity by showing that KSHV's ability to regulate HIF2α levels and localization to the endoplasmic reticulum (ER) in normoxia enables translation of viral lytic mRNAs through the HIF2α-regulated eIF4E2 translation-initiation complex. This mechanism of translation in infected cells is critical for lytic protein synthesis and contributes to KSHV-induced PDGFRA activation and VEGF secretion. Thus, KSHV regulation of the oxygen-sensing machinery allows virally infected cells to initiate translation via the mTOR-dependent eIF4E1 or the HIF2α-dependent, mTOR-independent, eIF4E2. This “translation initiation plasticity” (TRIP) is an oncoviral strategy used to optimize viral protein expression that links molecular strategies of viral replication to angiogenicity and oncogenesis.Fil: Méndez Solís, Omayra. University of Miami; Estados UnidosFil: Bendjennat, Mourad. University of Miami; Estados UnidosFil: Naipauer, Julian. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentina. University of Miami; Estados UnidosFil: Theodoridis, Phaedra R.. University of Miami; Estados UnidosFil: Ho, J.J. David. University of Miami; Estados UnidosFil: Verdun, Ramiro E.. University of Miami; Estados UnidosFil: Hare, Joshua M.. University of Miami; Estados UnidosFil: Cesarman, Ethel. Weill Cornell Medicine; Estados UnidosFil: Lee, Stephen. University of Miami; Estados UnidosFil: Mesri, Enrique Alfredo. University of Miami; Estados Unido

Oxidative stress and its association with ST resolution and clinical outcome measures in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention

Objective: Reperfusion of ischemic myocardium generates oxidative stress, which itself can mediate myocardial injury. So, in this study, we investigated the level of oxidative stress markers and its association with clinical outcomes in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention. Results: As indicated in the results, Post MI (Myocardial Infarction) heart failure was significantly higher in the group A (11 vs 4, p = 0.047). Complete STR (ST-segment resolution) was observed to be significantly higher in the group B (36 vs 17, p = 0.006). The SOD (Superoxide dismutase) and GPX (Glutathione peroxidase) levels were significantly higher in the group B compared to the other group (1547.51 ± 328.29 vs. 1449.97 ± 246.06, p = 0.019 and 60.62 ± 11.95 vs 57.41 ± 10.14, p = 0.042). The levels of GPX and SOD were shown to be directly related with complete STR and post PCI (Percutaneous coronary intervention)TIMI(Thrombolysis in Myocardial Infarction) flow 3 in the group A (p = 0.002 and p < 0.01, p = 0.005 and p < 0.02, respectively). © 2020, The Author(s)

Cytokine Production but Lack of Proliferation in Peripheral Blood Mononuclear Cells from Chronic Chagas' Disease Cardiomyopathy Patients in Response to T. cruzi Ribosomal P Proteins

Background:Trypanosoma cruzi ribosomal P proteins, P2β and P0, induce high levels of antibodies in patients with chronic Chagas' disease Cardiomyopathy (CCC). It is well known that these antibodies alter the beating rate of cardiomyocytes and provoke apoptosis by their interaction with β1-adrenergic and M2-muscarinic cardiac receptors. Based on these findings, we decided to study the cellular immune response to these proteins in CCC patients compared to non-infected individuals.Methodology/Principal findings:We evaluated proliferation, presence of surface activation markers and cytokine production in peripheral blood mononuclear cells (PBMC) stimulated with P2β, the C-terminal portion of P0 (CP0) proteins and T. cruzi lysate from CCC patients predominantly infected with TcVI lineage. PBMC from CCC patients cultured with P2β or CP0 proteins, failed to proliferate and express CD25 and HLA-DR on T cell populations. However, multiplex cytokine assays showed that these antigens triggered higher secretion of IL-10, TNF-α and GM-CSF by PBMC as well as both CD4+ and CD8+ T cells subsets of CCC subjects. Upon T. cruzi lysate stimulation, PBMC from CCC patients not only proliferated but also became activated within the context of Th1 response. Interestingly, T. cruzi lysate was also able to induce the secretion of GM-CSF by CD4+ or CD8+ T cells.Conclusions/Significance:Our results showed that although the lack of PBMC proliferation in CCC patients in response to ribosomal P proteins, the detection of IL-10, TNF-α and GM-CSF suggests that specific T cells could have both immunoregulatory and pro-inflammatory potential, which might modulate the immune response in Chagas' disease. Furthermore, it was possible to demonstrate for the first time that GM-CSF was produced by PBMC of CCC patients in response not only to recombinant ribosomal P proteins but also to parasite lysate, suggesting the value of this cytokine to evaluate T cells responses in T. cruzi infection.Fil: Longhi, Silvia Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Atienza, Augusto. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Ramos Mejía"; ArgentinaFil: Perez Prados, Graciela. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Juan A. Fernández"; ArgentinaFil: Buying, Alcinette. Torrey Pines Institute for Molecular Studies; Estados UnidosFil: Balouz, Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas; ArgentinaFil: Buscaglia, Carlos Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas; ArgentinaFil: Santos, Radleigh. Torrey Pines Institute for Molecular Studies; Estados UnidosFil: Tasso, Laura Mónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Bonato, Ricardo. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Ramos Mejía"; ArgentinaFil: Chiale, Pablo. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Ramos Mejía"; ArgentinaFil: Pinilla, Clemencia. Torrey Pines Institute for Molecular Studies; Estados UnidosFil: Judkowski, Valeria A.. Torrey Pines Institute for Molecular Studies; Estados UnidosFil: Gomez, Karina Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentin

Antitumorigenesis of antioxidants in a transgenic Rac1 model of Kaposi's sarcoma

Kaposi's sarcoma (KS) is the major AIDS-associated malignancy. It is characterized by the proliferation of spindle cells, inflammatory infiltrate, and aberrant angiogenesis caused by Kaposi's sarcoma herpesvirus (KSHV) infection. Small GTPase Rac1, an inflammatory signaling mediator triggering reactive oxygen species (ROS) production by NADPH-oxidases, is implicated in carcinogenesis and tumor angiogenesis. Here, we show that expression of a constitutively active Rac1 (RacCA) driven by the α-smooth muscle actin promoter in transgenic mice is sufficient to cause KS-like tumors through mechanisms involving ROS-driven proliferation, up-regulation of AKT signaling, and hypoxia-inducible factor 1-α–related angiogenesis. RacCA-induced tumors expressed KS phenotypic markers; displayed remarkable transcriptome overlap with KS lesions; and were, like KS, associated with male gender. The ROS scavenging agent N-acetyl-cysteine inhibited angiogenesis and completely abrogated transgenic RacCA tumor formation, indicating a causal role of ROS in tumorigenesis. Consistent with a pathogenic role in KS, immunohistochemical analysis revealed that Rac1 is overexpressed in KSHV+ spindle cells of AIDS-KS biopsies. Our results demonstrate the direct oncogenicity of Rac1 and ROS and their contribution to a KS-like malignant phenotype, further underscoring the carcinogenic potential of oxidative stress in the context of chronic infection and inflammation. They define the RacCA transgenic mouse as a model suitable for studying the role of oxidative stress in the pathogenesis and therapy of KS, with relevance to other inflammation-related malignancies. Our findings suggest host and viral genes triggering Rac1 or ROS production as key determinants of KS onset and potential KS chemopreventive or therapeutic targets