Interferon Regulatory Factor 4 (IRF-4) Targets IRF-5 to Regulate Epstein-Barr Virus Transformation

The cellular interferon regulatory factor-4 (IRF-4), which is a member of IRF family, is involved in the development of multiple myeloma and Epstein-Barr virus (EBV)-mediated transformation of B lymphocytes. However, the molecular mechanism of IRF-4 in cellular transformation is unknown. We have found that knockdown of IRF-4 leads to high expression of IRF-5, a pro-apoptotic member in the IRF family. Overexpression of IRF-4 represses IRF-5 expression. Reduction of IRF-4 leads to growth inhibition, and the restoration of IRF-4 by exogenous plasmids correlates with the growth recovery and reduces IRF-5 expression. In addition, IRF-4 negatively regulates IRF-5 promoter reporter activities and binds to IRF-5 promoters in vivo and in vitro. Knockdown of IRF-5 rescues IRF-4 knockdownmediated growth inhibition, and IRF-5 overexpression alone is sufficient to induce cellular growth inhibition of EBV-transformed cells. Therefore, IRF-5 is one of the targets of IRF-4, and IRF-4 regulates the growth of EBV-transformed cells partially through IRF-5. This work provides insight on how IRFs interact with one another to participate in viral pathogenesis and transformation

Interferon Regulatory Factor 4 (IRF-4) Targets IRF-5 to Regulate Epstein-Barr Virus Transformation

The cellular interferon regulatory factor-4 (IRF-4), which is a member of IRF family, is involved in the development of multiple myeloma and Epstein-Barr virus (EBV)-mediated transformation of B lymphocytes. However, the molecular mechanism of IRF-4 in cellular transformation is unknown. We have found that knockdown of IRF-4 leads to high expression of IRF-5, a pro-apoptotic member in the IRF family. Overexpression of IRF-4 represses IRF-5 expression. Reduction of IRF-4 leads to growth inhibition, and the restoration of IRF-4 by exogenous plasmids correlates with the growth recovery and reduces IRF-5 expression. In addition, IRF-4 negatively regulates IRF-5 promoter reporter activities and binds to IRF-5 promoters in vivo and in vitro. Knockdown of IRF-5 rescues IRF-4 knockdownmediated growth inhibition, and IRF-5 overexpression alone is sufficient to induce cellular growth inhibition of EBV-transformed cells. Therefore, IRF-5 is one of the targets of IRF-4, and IRF-4 regulates the growth of EBV-transformed cells partially through IRF-5. This work provides insight on how IRFs interact with one another to participate in viral pathogenesis and transformation

Premature Expression of the Latency-Related RNA Encoded by Bovine Herpesvirus Type 1 Correlates With Higher Levels of Beta Interferon RNA Expression in Productively Infected Cells

Bovine herpesvirus type 1 (BHV-1) is an important pathogen that can initiate bovine respiratory disease complex. Like other members of the subfamily Alphaherpesvirinae, BHV-1 establishes latency in sensory neurons. The latency-related (LR) gene expresses a family of alternatively spliced transcripts in infected sensory neurons that have the potential to encode several LR proteins. An LR mutant virus that contains three stop codons near the 5’ terminus of the first open reading frame in the LR gene does not express two LR proteins or reactivate from latency. In addition, the LR mutant virus induces higher levels of apoptosis in trigeminal ganglionic neurons and grows less efficiently in certain tissues of infected calves. In spite of the reduced pathogenesis, the LR mutant virus, wild-type BHV-1, and the LR rescued virus exhibit identical growth properties in cultured bovine cells. In this study, we demonstrated that during early phases of productive infection the LR mutant virus expressed higher levels of LR-RNA relative to the LR rescued virus or wt BHV-1. Bovine kidney cells infected with the LR mutant virus also induced higher levels of beta interferon RNA and interferon response genes. These results suggest that inappropriate expression of LR-RNA, in the absence of LR protein expression, may influence the latency-reactivation cycle and pathogenic potential of BHV-1

A Protein Encoded by the Bovine Herpesvirus 1 Latency-Related Gene Interacts with Specific Cellular Regulatory Proteins, Including CCAAT Enhancer Binding Protein Alpha

Following acute infection, bovine herpesvirus 1 establishes latency in sensory neurons of trigeminal ganglia (TG). Reactivation from latency occurs periodically, resulting in the shedding of infectious virus. The latency-related (LR) RNA is abundantly expressed in TG of latently infected calves, and the expression of LR proteins is necessary for dexamethasone-induced reactivation from latency. Previously published studies also identified an alternatively spliced LR transcript which is abundantly expressed in TG at 7 days after infection and has the potential to encode a novel LR fusion protein. Seven days after infection is when extensive viral gene expression is extinguished in TG and latency is established, suggesting that LR gene products influence the establishment of latency. In this study, we used a bacterial two-hybrid assay to identify cellular proteins that interact with the novel LR fusion protein. The LR fusion protein interacts with two proteins that can induce apoptosis (Bid and Cdc42) and with CCAAT enhancer binding protein alpha (C/EBP- α). Additional studies confirmed that the LR fusion protein interacts with human or insect C/EBP- α. C/EBP- α protein expression is induced in TG neurons of infected calves and after dexamethasone-induced reactivation from latency. Wildtype C/EBP- α, but not a DNA binding mutant of C/EBP-α, enhances plaque formation in bovine cells. We hypothesize that interactions between the LR fusion protein and C/EBP-α promote the establishment of latency

Cellular and molecular basis of progesterone-induced neuroprotection

Progesterone exerts several effects in the central nervous system not directly involved in reproduction or sex behavior. Non-reproductive effects are better observed under pathological conditions, and include stimulation of myelin formation, neurogenesis and neurosteroidogenesis, preserved mitochondrial function, neuroprotection, anti-inflammatory effects, decreased glutamate excitotoxicity, and regulation of mood, memory and cognition. In addition, the progesterone reduced derivative allopregnanolone shows anxiolytic, sedative and anesthetic properties after binding to GABAa receptors. In the present report we provide examples of [1] progesterone effects on the local synthesis of steroids (“neurosteroids”) in a demyelination model, [2] the requirement of the classical progesterone receptor for the anti- inflammatory effects in mice with spinal cord injury, and [3] the protective role of progesterone and allopregnanolone in a mouse model of neurodegeneration. In conclusion, the beneficial effects observed in different experimental paradigms support the versatile properties of progesterone in animal models of central nervous system disorders.La progesterona produce varios efectos en el sistema nervioso central no relacionados a la reproducción o comportamiento sexual. Estos efectos adicionales se observan preferentemente bajo condiciones patológicas, e incluyen la estimulación de la formación de mielina, la neurogenesis y neuroesteroidogenesis, el mantenimiento de la función mitocondrial, efectos anti-inflamatorios, disminución de la excitotoxicidad del glutamato y regulación del humor, memoria y conocimiento. En agregado, el derivado reducido de progesterona – alopregnanolona muestra propiedades ansiolíticas, sedantes y anestésicas luego de su unión al receptor GABAa. Este Minireview detalla los efectos de progesterona sobre [1] la síntesis local de esteroides (“neuroesteroides”), en un modelo de desmielinizacion, [2] ejemplifica el requerimiento del receptor clásico de progesterona para los efectos anti-inflamatorios en un modelo de injuria espinal en ratón, y finalmente [3] discute el rol protector de la progesterona y de la alopregnanolona en un modelo murino de degeneración de motoneurona. Como conclusión, los efectos beneficiosos mostrados en diferentes paradigmas experimentales apoyan las propiedades versátiles de la progesterona en modelos de patologías del sistema nervioso central.Fil: de Nicola, Alejandro Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Bioquímica Humana; ArgentinaFil: Garay, Laura Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Bioquímica Humana; ArgentinaFil: Meyer, Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Labombarda, Maria Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Bioquímica Humana; ArgentinaFil: Gonzalez Deniselle, Maria Claudia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Fisiología; Argentin

TLR-TRIF Pathway Enhances the Expression of KSHV Replication and Transcription Activator

Background: Host innate immunity is against virus infection and replication. Results: Toll-like receptor 3 activation leads to enhanced expression of a key Kaposi’s sarcoma-associated herpesvirus (KSHV) protein. Conclusion: KSHV uses host Toll-like receptor pathway to augment its critical gene expression. Significance: A virus may usurp host innate immunity for its own benefits

Desenvolvimento de estratégias terapêuticas baseadas em esteroides neuroativos e neuroesteroides para o tratamento de neuropatologias experimentais

Los esteroides activos en el sistema nervioso ("neuroactivos") ejercen actividades neuroprotectoras o neurotóxicas, dependiendo de su estructura química, de las concentraciones circulantes o tisulares, del tipo de receptores intervinientes y de los mecanismos de señalización intracelular empleados. Estas propiedades han sido estudiadas en modelos animales de neuropatologías humanas. Bajo condiciones experimentales que remedan el traumatismo de la médula espinal, dolor neuropático, esclerosis múltiple y esclerosis lateral amiotrófica, el tratamiento con progesterona produjo beneficios terapéuticos relacionados con la neuroprotección, re-mielinización e inhibición de la neuroinflamación. Por otra parte, estudios realizados en animales hipertensos demuestran una pronunciada encefalopatía en cuya etiopatogenia interviene la hiperfunción del sistema mineralocorticoide, ya que similares anormalidades neuroquímicas aparecen en animales normales tratados con mineralocorticoides. Por consiguiente, la neurotoxicidad podría ser consecuencia de la hi-peractividad del sistema mineralocorticoide. La encefalopatía de la hipertensión es similar a la de la diabetes mellitus y a la del cerebro añoso. En los tres casos, los estrógenos actúan como agentes neuroprotectores, promoviendo la neurogéne-sis hipocampal, la expresión de factores neurotróficos y disminuyendo la astrogliosis, confirmándose la plasticidad del sistema nervioso al estímulo estrogénico. Por consiguiente, el empleo de esteroides neuroactivos en modelos animales hace factible la transferencia a corto plazo de los resultados experimentales a la clínica humana.Steroids showing activity on the nervous system are known as "neuroactive steroids". They exert neuroprotective or neu-rotoxic activities, depending on their chemical structure, circulating or tissue concentrations, binding to different receptors and the mechanisms of intracellular signalling employed. In order to elucidate these properties, work was performed on animal models of human neuropathologies, including spinal cord injury, neuropathic pain, multiple sclerosis, and amy-otrophic lateral sclerosis. In these models, treatment with progesterone has shown great therapeutic effectiveness. In another set of studies, it was shown that hypertensive animals bear a pronounced encephalopathy, possibly caused by an overdrive of the mineralocorticoid system. It has been suggested that overdrive of the mineralocorticoid system plays a neurotoxic role, based on the development of similar brain abnormalities following mineralocorticoid treatment of otherwise normal animals. Hypertensive encephalopathy is similar to that developed by diabetes mellitus and aging animals. In the three cases, estrogen treatment provided strong neuroprotection, as shown by enhanced hippocampal neu-rogenesis, increased neurotrophic factor expression and decreased astrogliosis. Thus, the use of estrogens supports the regenerative capacity and plasticity of the nervous system. Therefore, animal models become useful tools to transfer experimental data to the human patient in the short-term.Os esteroides ativos no sistema nervoso ("neuroativos") exercem atividades neuroprotetoras ou neurotóxicas, de-pendendo de sua estrutura química, das concentrações circulantes ou tissulares, do tipo de receptores intervenientes e dos mecanismos de sinalização intracelular utilizados. Estas propriedades têm sido estudadas em modelos animais de neuropatologias humanas. Sob condições experimentais que remedam o traumatismo da medula espinal, dor neuro-pática, esclerose múltipla e esclerose lateral amiotrófica, o tratamento com progesterona produziu benefícios terapêu-ticos relacionados com a neuroproteção, remielinização e ini-bição da neuroinflamação. Por outra parte, estudos realizados em animais hipertensos demonstram uma pronunciada encefalopatia em cuja etiopatogenia intervém a hiperfunção do sistema mineralocorticoide, visto que similares anormalidades neuroquímicas aparecem em animais normais tratados com mineralocorticoides. Por conseguinte, a neuroto-xicidade poderia ser consequência da hiperatividade do sistema mineralocorticoide. A encefalopatia da hipertensão é similar à da diabetes mellitus e à do cérebro idoso. Nos três casos, os estrogênios atuam como agentes neuroprotetores, promovendo a neurogênese hipocampal, a expressão de fa-tores neurotróficos e diminuindo a astrogliose, confirmando-se a plasticidade do sistema nervoso ao estímulo estrogênico. Por conseguinte, o emprego de esteroides neuroativos em modelos animais torna fatível a transferência em curto prazo dos resultados experimentais para a clínica humana.Fil: de Nicola, Alejandro Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); ArgentinaFil: Beauquis, Juan. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); ArgentinaFil: Coronel, Maria Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); ArgentinaFil: Garay, Laura Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); ArgentinaFil: Gonzalez Deniselle, Maria Claudia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); ArgentinaFil: Gonzalez, Susana Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); ArgentinaFil: Labombarda, Maria Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); ArgentinaFil: Pietranera, Luciana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); ArgentinaFil: Saravia, Flavia Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); ArgentinaFil: Meyer, Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); ArgentinaFil: Gargiulo Monachelli, Gisella Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); ArgentinaFil: Brocca, María Elvira. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); ArgentinaFil: Overveld, Lydia Van . Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); ArgentinaFil: Lima, Analia Ethel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); ArgentinaFil: Roig, Paulina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); Argentin

Cellular and molecular basis of progesterone-induced neuroprotection

Progesterone exerts several effects in the central nervous system not directly involved in reproduction or sex behavior. Non-reproductive effects are better observed under pathological conditions, and include stimulation of myelin formation, neurogenesis and neurosteroidogenesis, preserved mitochondrial function, neuroprotection, anti-inflammatory effects, decreased glutamate excitotoxicity, and regulation of mood, memory and cognition. In addition, the progesterone reduced derivative allopregnanolone shows anxiolytic, sedative and anesthetic properties after binding to GABAa receptors. In the present report we provide examples of [1] progesterone effects on the local synthesis of steroids (“neurosteroids”) in a demyelination model, [2] the requirement of the classical progesterone receptor for the antiinflammatory effects in mice with spinal cord injury, and [3] the protective role of progesterone and allopregnanolone in a mouse model of neurodegeneration. In conclusion, the beneficial effects observed in different experimental paradigms support the versatile properties of progesterone in animal models of central nervous system disorders.La progesterona produce varios efectos en el sistema nervioso central no relacionados a la reproducción o comportamiento sexual. Estos efectos adicionales se observan preferentemente bajo condiciones patológicas, e incluyen la estimulación de la formación de mielina, la neurogenesis y neuroesteroidogenesis, el mantenimiento de la función mitocondrial, efectos anti-inflamatorios, disminución de la excitotoxicidad del glutamato y regulación del humor, memoria y conocimiento. En agregado, el derivado reducido de progesterona – alopregnanolona – muestra propiedades ansiolíticas, sedantes y anestésicas luego de su unión al receptor GABAa. Este Minireview detalla los efectos de progesterona sobre [1] la síntesis local de esteroides (“neuroesteroides”), en un modelo de desmielinizacion, [2] ejemplifica el requerimiento del receptor clásico de progesterona para los efectos anti-inflamatorios en un modelo de injuria espinal en ratón, y finalmente [3] discute el rol protector de la progesterona y de la alopregnanolona en un modelo murino de degeneración de motoneurona. Como conclusión, los efectos beneficiosos mostrados en diferentes paradigmas experimentales apoyan las propiedades versátiles de la progesterona en modelos de patologías del sistema nervioso central.Sociedad Argentina de Fisiologí

Blunted Response to Combination Antiretroviral Therapy in HIV Elite Controllers: An International HIV Controller Collaboration

Objective: HIV “elite controllers” (ECs) spontaneously control viral load, but some eventually require combination antiretroviral treatment (cART), due to a loss of viral control or a decline in CD4 T-cell counts. Here we studied the CD4 T-cell count dynamics after cART initiation among 34 ECs followed in U.S. and European cohorts, by comparison with chronically viremic patients (VIRs). Methods: ECs were defined as patients with at least ≥5 viral load (VL) measurements below 400 copies/mL during at least a 5-year period despite never receiving ART and were selected from the French ANRS CO18 cohort, the U.S. SCOPE cohort, the International HIV Controllers study and the European CASCADE collaboration. VIRs were selected from the ANRS COPANA cohort of recently-diagnosed (<1 year) ART-naïve HIV-1-infected adults. CD4 T-cell count dynamics after cART initiation in both groups were modelled with piecewise mixed linear models. Results: After cART initiation, CD4 T-cell counts showed a biphasic rise in VIRs with: an initial rapid increase during the first 3 months (+0.63/month), followed by +0.19/month. This first rapid phase was not observed in ECs, in whom the CD4Tc count increased steadily, at a rate similar to that of the second phase observed in VIRs. After cART initiation at a CD4 T-cell count of 300/mm3, the estimated mean CD4 T-cell gain during the first 12 months was 139/mm3 in VIRs and 80/mm3 in ECs (p = 0.048). Conclusions: cART increases CD4 T-cell counts in elite controllers, albeit less markedly than in other patients

The ocean sampling day consortium.

Ocean Sampling Day was initiated by the EU-funded Micro B3 (Marine Microbial Biodiversity, Bioinformatics, Biotechnology) project to obtain a snapshot of the marine microbial biodiversity and function of the world's oceans. It is a simultaneous global mega-sequencing campaign aiming to generate the largest standardized microbial data set in a single day. This will be achievable only through the coordinated efforts of an Ocean Sampling Day Consortium, supportive partnerships and networks between sites. This commentary outlines the establishment, function and aims of the Consortium and describes our vision for a sustainable study of marine microbial communities and their embedded functional traits