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There is an urgent need to identify efficient antiviral compounds to combat existing and emerging RNA virus infections, particularly those related to seasonal and pandemic influenza outbreaks. While inhibitors of the influenza viral integral membrane proton channel protein (M2), neuraminidase (NA), and cap-dependent endonuclease are available, circulating influenza viruses acquire resistance over time. Thus, the need for the development of additional anti-influenza drugs with novel mechanisms of action exists. In the present study, a cell-based screening assay and a small molecule library were used to screen for activities that antagonized influenza A non-structural protein 1 (NS1), a highly conserved, multifunctional accessory protein that inhibits the type I interferon response against influenza. Two potential anti-influenza agents, compounds 157 and 164, were identified with anti-NS1 activity, resulting in the reduction of A/PR/8/34(H1N1) influenza A virus replication and the restoration of IFN-β expression in human lung epithelial A549 cells. A 3D pharmacophore modeling study of the active compounds provided a glimpse of the structural motifs that may contribute to anti-influenza virus activity. This screening approach is amenable to a broader analysis of small molecule compounds to inhibit other viral targets.

Il contributo riesamina in maniera critica i cicli iconografici musivi ravennati, conservati o noti da fonti, che raffigurano figure femminili di diversa estrazione sociale, esaminando il complesso sistema di simboli tramite cui la manifestazione dello status veniva codificata all'interno della società di riferimento

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We report the molecular evidence of dengue virus (DENV) and chikungunya virus (CHIKV) infection in symptomatic individuals in Cameroon and Gabon, respectively. Arthropod-borne viruses (arboviruses) are distributed in the tropical or subtropical regions, with DENV having the highest burden. The morbidity and mortality related to arboviral diseases raise the concern of timely and efficient surveillance and care. Our aim was to assess the circulation of arboviruses [DENV, CHIKV, Zika virus (ZIKV)] among febrile patients in Dschang (West Cameroon) and Kyé-ossi (South Cameroon, border with Gabon and Equatorial Guinea). Dried blood spots were collected from 601 consenting febrile patients, and 194 Plasmodium spp.-negative samples were tested for the molecular detection of cases of DENV, CHIKV and ZIKV infection. Overall, no case of ZIKV infection was found, whereas one case of DENV infection and one case of CHIKV infection were detected in Dschang and Kyé-ossi, respectively, with the CHIKV-infected patient being resident in Gabon. Our findings suggest the need to establish an active surveillance of arbovirus transmission in Cameroon and bordering countries.

Interferon Regulatory Factors (IRFs) are key regulators of immunity, cell survival and apoptosis. IRF transcriptional activity and subcellular localization are tightly regulated by posttranscriptional modifications including phosphorylation. The IκB kinase family member IKK-ε is essential in regulating antiviral innate immunity mediated by IRFs but is now also recognized as an oncoprotein amplified and overexpressed in breast cancer cell lines and patient-derived tumors. In the present study, we report that the tumor suppressor IRF-1 is a specific target of IKK-ε in breast cancer cells. IKK-ε-mediated phosphorylation of IRF-1 dramatically decreases IRF-1 protein stability, accelerating IRF-1 degradation and quenching IRF-1 transcriptional activity. Chemical inhibition of IKK-ε activity, fully restores IRF-1 levels and function and positively correlates with inhibition of cell growth and proliferation of breast cancer cells. By using a breast cancer cell line stably expressing a dominant negative version of IRF-1 we were able to demonstrate that IKK-ε preferentially exerts its oncogenic potential in breast cancer through the regulation of IRF-1 and point to the IKK-ε-mediated phosphorylation of IRF-1 as a therapeutic target to overcome IKK-ε-mediated tumorigenesis.

The RNA purification is the gold standard for the detection of SARS-CoV-2 in swab samples, but it is dependent on the availability of chemical reagents. In this study, we evaluated the heat treatment method without RNA extraction as a reliable option to nucleic acid purification.

The archaeological excavations carried out in 1993-1994 in Ravenna, via d’Azeglio, unearthed a large residential sector of the ancient city. The huge amount of materials recovered during the fieldwork has been recently reconsidered thanks to a collaboration between the University of Bologna and the Superintendence for Fine Arts and Landscapes for the provinces of Ravenna, Forlì-Cesena and Rimini. The paper aims at presenting some preliminary results about the examination of specific categories of archaeological items, such as stone furniture, marble revetments, amphorae, lamps and painted plaster. The material culture under scrutiny covers a long time span with reference to the different settlement phases and mirrors the social and economic status of the owners. New reconstructions about the opus sectile and painted plaster decoration are proposed, as well as an overall analysis of transport, storage and lighting pottery items, with specific focus on the Late Antique materials.

Il contributo analizza sotto il profilo archeologico ed epigrafico alcuni contenitori anforari bollati di età tardo repubblicana e alto imperiale provenienti dallo scavo della domus di via d'Azeglio a Ravenna

Catalogo degli elementi lapidei del complesso di S. Stefano a Kos

ll contributo prende in esame gli elementi lapidei pertinenti all'ordine architettonico degli edifici del complesso di S. Stefano, esaminandone aspetti materiali, tecnologici, stilistici al fine di ricostruire la morfologia degli elevati dei contesti in esame e le scelte economico-stilistiche operate dai committenti

ll contributo prende in esame gli elementi lapidei pertinenti al ciborio della basilica sud del complesso di S. Stefano, esaminandone aspetti materiali, tecnologici, stilistici al fine di ricostruire la morfologia degli elevati e le scelte economico-stilistiche operate dai committenti

Il contributo analizza il principale luogo di culto (basilica sud) del complesso di S. Stefano a Kos nella sua evoluzione storico-architettonica dalla fondazione alla defunzionalizzazione

Catalogo delle strutture murarie del complesso di S. Stefano a Kos

Il contributo presenta tre sarcofagi marmorei esposti nella Raccolta Lercaro di Bologna. Il primo manufatto, un sarcofago a fregio continuo con episodi neo e veterotestamentari, è riconducibile ad una nota tipologia diffusa nel primo trentennio del IV secolo. Oltre ad un’analisi stilistico-iconografica del tessuto narrativo, si propone una lettura degli interventi integrativi post-antichi, che trovano riscontro nella prassi di restauro diffusa durante il XVIII secolo in ambito romano. Negli altri due sarcofagi è invece possibile riconoscere pregevoli copie di originali romani di età medio e tardo-imperiale. Di essi si identificano i modelli e si propone una lettura che mira a ricostruire la genesi di eventuali anomalie iconografiche. La produzione di questi manufatti ben si colloca nella temperie artistico-culturale del primo ventennio del XX secolo, documentando un fenomeno ancora poco indagato di riproduzione e contraffazione dell’antico, che tra il XVIII e il XX secolo assunse forme e dinamiche del tutto inedite. The paper presents three marble sarcophagi currently exhibited in the Lercaro Collection in Bologna. The first example can be traced back to the “continuous frieze” typology with scenes from the Old and the New Testament, dating from the first three decades of the 4th century. The analysis focuses on its stylistic and iconographic features, as well as on the identification of later integrations. The latter ones reflect the approach in the restoration of antiquities that developed during the Eighteenth century in Rome. The other two sarcophagi are fine copies of Roman artworks dating back to the mid and late Imperial times. The paper examines their models and seeks to trace the development of iconographic discrepancies. The creation of these products fits into the artistic activity of the beginning of the 20th century. They record a phenomenon of counterfeit and imitation artworks that was substantially widespread between the 18th and the 19th century but is still little known.

Background On 11 March 2020, the World Health Organisation (WHO) declared the coronavirus disease 2019 (COVID-19) outbreak to be a pandemic. As the mosquito season progressed, the understandable concern that mosquitoes could transmit the virus began to increase among the general public and public health organisations. We have investigated the vector competence of Culex pipiens and Aedes albopictus, the two most common species of vector mosquitoes in Europe, for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Due to the very unusual feeding behaviour of Ae. albopictus, we also evaluated the role of this mosquito in a potential mechanical transmission of the virus. Methods For the vector competence study, mosquitoes were allowed to take several infectious blood meals. The mosquitoes were then collected and analysed at 0, 3, 7 and 10 days post-feeding. For the mechanical transmission test, Ae. albopictus females were allowed to feed for a short time on a feeder containing infectious blood and then on a feeder containing virus-free blood. Both mosquitoes and blood were tested for viral presence. Results Culex pipiens and Ae. albopictus were found not be competent vectors for SARS-CoV-2, and Ae. albopictus was unable to mechanically transmit the virus. Conclusions This is the first study to show that the most common species of vector mosquitoes in Europe do not transmit SARS-CoV-2 and that Ae. albopictus is unable to mechanically transmit the virus from a positive host to a healthy host through host-feeding. Graphical Abstract

The paper presents the main activities and outcomes of the Byzart - Byzantine Art and Archaeology on Europeana - project

Lo studio dei processi di cantiere in relazione all’architettura antica rappresenta un ambito di indagine solo recentemente approfondito nella letteratura scientifica. Esso offre dati di grande interesse circa la molteplicità di azioni che contribuirono alla nascita di grandi opere edilizie, con riguardo per le strutture e le tecniche costruttive e produttive, ma anche per la componente umana e professionale coinvolta nelle diverse fasi del lavoro. Il volume riguarda il cantiere edilizio di età tardoantica e bizantina e ne prende in esame un aspetto particolare, quello del ciclo di lavorazione del marmo e il segmento del mondo del lavoro a esso correlato. La prospettiva inedita da cui i processi produttivi e manifatturieri sono indagati è quella dei marchi di lavorazione, sigle tracciate sugli arredi da maestranze e funzionari in diverse fasi del ciclo di produzione e distribuzione. Si raccolgono qui 3393 evidenze epigrafiche, apposte su un totale di 2951 manufatti, alcuni dei quali siglati più volte. Per esse si propone una classificazione tipologica basata su un criterio crono-contestuale, finalizzata a comprendere la funzione dei segni all’interno della filiera costruttiva e mettere in luce il ruolo svolto dalle differenti figure professionali nell’ambito della fabbrica edilizia. La possibilità di fare convergere sullo stesso tema di ricerca fonti complementari – archeologiche, epigrafiche, storiografiche, agiografiche, legislative – consente la ricostruzione di un segmento del lavoro del mondo antico estremamente articolato, in cui entravano in gioco numerosi attori, operanti a diversi livelli della società. In quest’ottica, le notae lapicidarum offrono un ampio spaccato sulla vita del cantiere, le istanze tecniche ed economiche in atto e le relazioni tra i gruppi sociali coinvolti. Esse testimoniano l’orizzonte culturale in cui le maestranze si collocavano e gettano luce su una categoria di lavoratori che per tradizione era solita scomparire dietro la propria opera, senza lasciare memoria di sé e della propria individualità.

The development of Information Technology and Digital Humanities has brought numerous significant changes to the Cultural Heritage domain. The Digital Humanities has become a dynamic and fertile research field, and new projects and opportunities are constantly flourishing. The BYZART project perfectly fits this context. This project is coordinated by the Department of History and Cultures of the University of Bologna, embracing a wide consortium of partners from Bulgaria, Greece and Italy. It aims at enhancing Byzantine and Post-Byzantine artistic and cultural heritage within the Europeana platform. This project will enrich the existing Europeanacollections with about 75,000 new cultural and artistic multimedia objects relevant to Byzantine history and culture, including collections of digitized photos, video and audio content, and 3-D surveys and reconstructions. We have also established a liaison between the new materials and Byzantine-related content already existing on Europeana. The archival material collected and digitized by the BYZART consortium is of the greatest cultural and art-historical importance, but until now, it has not been properly evaluated or published. For this reason, BYZART aims to guarantee the preservation and evaluation of significant cultural heritage objects from a wide range of contexts, while also making them accessible to scholarly and general audiences alike.

Il contributo presenta alcune sigle marmorarie reperite sulla superficie di mense marmoree provenienti da diversi contesti archeologici del Mediterraneo orientale e occidentale. Si tratta di iscrizioni disposte in forma monogrammatica ed incise sul recto di manufatti tipologicamente affini. L’interpretazione tradizionalmente proposta per i singoli documenti epigrafici fa riferimento a generiche indicazioni di committenza, talora correlate all’autorità episcopale locale. Una revisione sistematica della documentazione esistente consente tuttavia di avanzare nuove ipotesi a riguardo, ponendo in relazione i singoli monogrammi con le maestranze responsabili della manifattura degli elementi d’arredo. Vengono presentati i principali nuclei epigrafici riconosciuti, proponendone l’attribuzione ad officine marmorarie specializzate localizzate nei pressi della capitale costantinopolitana e cercando di verificarne la relazione con ambiti territoriali e culturali specifici.

Il contributo descrive gli apprestamenti produttivi di età bizantina intercettati dallo scavo della cella del tempio presso il Caput Aquae del Pretorio di Gortina

Current combination antiretroviral therapies (cART) are unable to eradicate HIV-1 from infected individuals because of the establishment of proviral latency in long-lived cellular reservoirs. The shock-and-kill approach aims to reactivate viral replication from the latent state (shock) using latency-reversing agents (LRAs), followed by the elimination of reactivated virus-producing cells (kill) by specific therapeutics. The NF-κB RelA/p50 heterodimer has been characterized as an essential component of reactivation of the latent HIV-1 long terminal repeat (LTR). Nevertheless, prolonged NF-κB activation contributes to the development of various autoimmune, inflammatory, and malignant disorders. In the present study, we established a cellular model of HIV-1 latency in J-Lat CD4(+) T cells that stably expressed the NF-κB superrepressor IκB-α 2NΔ4 and demonstrate that conventional treatments with bryostatin-1 and hexamethylenebisacetamide (HMBA) or ionomycin synergistically reactivated HIV-1 from latency, even under conditions where NF-κB activation was repressed. Using specific calcineurin phosphatase, p38, and MEK1/MEK2 kinase inhibitors or specific short hairpin RNAs, c-Jun was identified to be an essential factor binding to the LTR enhancer κB sites and mediating the combined synergistic reactivation effect. Furthermore, acetylsalicylic acid (ASA), a potent inhibitor of the NF-κB activator kinase IκB kinase β (IKK-β), did not significantly diminish reactivation in a primary CD4(+) T central memory (T(CM)) cell latency model. The present work demonstrates that the shock phase of the shock-and-kill approach to reverse HIV-1 latency may be achieved in the absence of NF-κB, with the potential to avoid unwanted autoimmune- and or inflammation-related side effects associated with latency-reversing strategies. IMPORTANCE The shock-and-kill approach consists of the reactivation of HIV-1 replication from latency using latency-reversing agents (LRAs), followed by the elimination of reactivated virus-producing cells. The cellular transcription factor NF-κB is considered a master mediator of HIV-1 escape from latency induced by LRAs. Nevertheless, a systemic activation of NF-κB in HIV-1-infected patients resulting from the combined administration of different LRAs could represent a potential risk, especially in the case of a prolonged treatment. We demonstrate here that conventional treatments with bryostatin-1 and hexamethylenebisacetamide (HMBA) or ionomycin synergistically reactivate HIV-1 from latency, even under conditions where NF-κB activation is repressed. Our study provides a molecular proof of concept for the use of anti-inflammatory drugs, like aspirin, capable of inhibiting NF-κB in patients under combination antiretroviral therapy during the shock-and-kill approach, to avoid potential autoimmune and inflammatory disorders that can be elicited by combinations of LRAs.

Interferon responsive factor 1 (IRF-1) is a pleiotropic transcription factor, possessing non-redundant biological activities that depend on its interaction with different protein partners and multiple post-translational modifications including phosphorylation. In particular, a 5′-SXXXSXS-3′ motif of the protein represents the target of the IκB-related kinases, TANK-binding kinase (TBK)-1 and inhibitor of nuclear factor kappa-B kinase (IKK)-ε. Here, a 3D model of human IRF-1 was determined by using multi-template comparative modeling and molecular dynamics approaches. Models obtained through either phosphorylation or aspartate mutation of residues 215, 219 and 221 were also calculated and compared to the wild type. Calculations indicated that each of these modifications mainly induces a rigidification of the protein structure and only slightly changes in electrostatics and hydrophobicity of IRF-1 surface, resulting in the impairment of the capacity of IRF-1 containing as partate mutations (S221D and S215D/S219D/S221D) to synergize with tumour necrosis factor (TNF)-α stimulation in inducing interferon (IFN) promoter-mediated reporter gene activation. Therefore, these changes are qualitatively correlated to the amount of negative charge located on the 215–221 segments of IRF-1 by phosphorylation or aspartate mutation. Hypotheses on the structural mechanism that governs the phosphorylation-related damping of IRF-1 activity were also drawn. Communicated by Ramaswamy H. Sarma

In 2017, a chikungunya outbreak in central Italy later evolved into a secondary cluster in southern Italy, providing evidence of disease emergence in new areas. Officials have taken action to raise awareness among clinicians and the general population, increase timely case detection, reduce mosquito breeding sites, and promote mosquito bite prevention.

Background Chikungunya virus is an emerging mosquito-borne pathogen with a wide global distribution. With the severe morbidity that it causes, chikungunya virus is a major public health problem in the affected areas and poses a considerable risk for unaffected areas hosting competent vector populations. In the summer of 2017, Italy experienced a chikungunya virus outbreak that spread in the Lazio region and caused a secondary outbreak in the Calabrian village of Guardavalle, with a final case number of 436. The causative strain was recognized as an Indian Ocean lineage (IOL) virus. Methods To understand the underlying genetic and molecular features of the outbreak virus, viruses from mosquito pools and clinical samples were isolated in cell culture and subjected to whole-genome sequencing and genetic analyses. Results All 8 characterized genomes shared a high sequence identity. A distinct substitution pattern in the Italian 2017 viruses (including mutations in E1, E2, and nsP4) was partly shared with the Pakistani 2016 outbreak viruses. Evolutionary analyses indicate that these 2 recent outbreaks and several geographically widely distributed, travel-associated viruses form a cluster of rapidly emerging Indian-origin IOL viruses. Conclusions Our analyses show that the 2017 Italian outbreak virus belongs to a cluster of novel IOL chikungunya viruses originating in India. Their emergence calls for enhanced monitoring and strengthened preparedness measures, including vector control programs and raised awareness among general practitioners in countries potentially at risk.

Contestualizzazione storico-topografica della prima cerchia muraria bolognese (le cosidette "mura di selenite"), in relazione con le vicende delle "4 croci".

Since 2007 the University of Bologna has started new archaeological research in the island of Kos. The article offers a description of the results of researches in the episcopal complex of the city, dating from the VIth to the Xth century.

The interferon regulatory factor (IRF) family consists of transcriptional regulators that exert multifaceted and versatile functions in multiple biological processes. Their crucial role as central mediators in the establishment and execution of host immunity in response to pathogen-derived signals downstream pattern recognition receptors (PRRs) makes IRFs a hallmark of the host antiviral response. They function as hub molecules at the crossroad of different signaling pathways for the induction of interferon (IFN) and inflammatory cytokines, as well as of antiviral and immunomodulatory genes even in an IFN-independent manner. By regulating the development and activity of immune cells, IRFs also function as a bridge between innate and adaptive responses. As such, IRFs represent attractive and compulsive targets in viral strategies to subvert antiviral signaling. In this study, we discuss current knowledge on the wide array of strategies put in place by pathogenic viruses to evade, subvert, and/or hijack these essential components of host antiviral immunity.

Many passages from ancient literary sources notice the theoretical and practical training process requested for architects and engineers in Late Antiquity and Early Byzantium. In this paper, firstly we try to explain how Anthemius of Tralles and Isidore of Miletus the Elder, the famous architects of Saint Sofia in Constantinople, fully embody the pattern outlined by the sources. Furthermore, through the case of the two Isidores, we verify in which terms family relationships affect the transmission of technical and artisanal skills. KeyworDs – Byzantine architects, Isidore of Miletus, Saint Sophia of Constantinople, training, transmission of skills. Architetti bizantini, formazione, Isidoro di Mileto, Santa Sofia di Costantinopoli, trasmissione di saperi. Contraddicendo la tradizionale reticenza delle fonti antiche circa i nomi degli artefici di imprese architettoniche, Procopio di Cesarea nel primo libro del De Aedificiis suggella l’incipit della descrizione di S. Sofia con il nome dei suoi costruttori, Antemio di Tralle ed Isidoro di Mileto (Procop. Aed. I 1, 24). L’eccezionalita dell’impresa, considerata come il «simbolo dell’edificazione giustinianea» 1, motivava in certa misura l’uscita dall’anonimato e la menzione esplicita dei due μηχανοποιοί chiamati a corte per espressa volonta imperiale come responsabili del cantiere della Μeγάλη ’Eκκλη σία (Fig. 1). Insieme al sovrano, che occupava il vertice gerarchico non solo della societa ma anche della stessa impresa edilizia, i due personaggi rappresentano infatti i protagonisti dell’opera, che e stata definita come un’ekphrasis del τρόπος, ovvero una descrizione del modo in cui si attuo il grandioso progetto edilizio 2. Essi sono connotati come i piu alti consiglieri palatini per problemi di ordine edilizio, responsabili della soluzione di numerosi imprevisti tecnici occorsi durante lo svolgimento della fabbrica 1 Cesaretti 2011, 7. 2 Fobelli 2011, 68-70. La famiglia tardoantica. Societa, diritto, religione A cura di V. Neri e B. Girotti Milano, LED, 2016 http://www.ledonline.it/index.php/Erga-Logoi/pages/view/qel-5-famiglia-tardoantica

This review will summarize main characteristics and functions of IRF-7. IRF-7 and the highly homologous IRF-3 are two members of the IRF family of transcription factors that have emerged as crucial regulators of type I interferon (IFN) in response to pathogenic infections downstream pathogen recognition receptors. IRF-7 is also part of a positive-feedback regulatory loop essential for sustained IFN responses. Thus, tight regulation of its expression and activity is necessary to balance IFN-mediated beneficial effects and unwanted pathological consequences of IFN overproduction. Its role as an antiviral factor independent of IFN expression, and its involvement in other cellular functions beyond antiviral functions, including regulation of oncogenesis and metabolism, underscore its important role in the regulation of cellular homeostasis.

In addition to its ability to regulate HIV-1 promoter activation, the viral transactivator Tat also functions as a determinant of pathogenesis and disease progression by directly and indirectly modulating the host anti-HIV response, largely through the capacity of Tat to interact with and modulate the activities of multiple host proteins. We previously demonstrated that Tat modulated both viral and host transcriptional machinery by interacting with the cellular transcription factor interferon regulatory factor 1 (IRF-1). In the present study, we investigated the mechanistic basis and functional significance of Tat−IRF-1 interaction and demonstrate that Tat dramatically decreased IRF-1 protein stability. To accomplish this, Tat exploited the cellular HDM2 (human double minute 2 protein) ubiquitin ligase to accelerate IRF-1 proteasome-mediated degradation, resulting in a quenching of IRF-1 transcriptional activity during HIV-1 infection. These data identify IRF-1 as a new target of Tat-induced modulation of the cellular protein machinery and reveal a new strategy developed by HIV-1 to evade host immune responses., IMPORTANCE Current therapies have dramatically reduced morbidity and mortality associated with HIV infection and have converted infection from a fatal pathology to a chronic disease that is manageable via antiretroviral therapy. Nevertheless, HIV-1 infection remains a challenge, and the identification of useful cellular targets for therapeutic intervention remains a major goal. The cellular transcription factor IRF-1 impacts various physiological functions, including the immune response to viral infection. In this study, we have identified a unique mechanism by which HIV-1 evades IRF-1-mediated host immune responses and show that the viral protein Tat accelerates IRF-1 proteasome-mediated degradation and inactivates IRF-1 function. Restoration of IRF-1 functionality may thus be regarded as a potential strategy to reinstate both a direct antiviral response and a more broadly acting immune regulatory circuit.

Antiretroviral therapy (ART) has proved highly effective in suppressing HIV-1 replication and disease progression. Nevertheless, ART has failed to eliminate the virus from infected individuals. The main obstacle to HIV-1 eradication is the persistence of cellular viral reservoirs. Therefore, the "shock-and-kill" strategy was proposed consisting of inducing HIV-1 escape from latency, in the presence of ART. This is followed by the elimination of reactivated, virus-producing cells. Immune modulators, including protein kinase C (PKC) activators, anti-leukemic drugs and histone deacetylase inhibitors (HDACis) have all demonstrated efficacy in the reactivation of latent virus replication. This review will focus on the potential use of these small molecules in the "shock and kill" strategy, the molecular basis for their action and the potential advantages of their immune-modulating activities.

Genetic vaccines are safe cost-effective approaches to immunization but DNA immunization is an inefficient process. There is, therefore, a pressing need for adjuvants capable of enhancing the immunogenicity and effectiveness of these vaccines. This is particularly important for diseases for which successful vaccines are still lacking, such as cancer and infectious diseases including HIV-1/AIDS. Here we report an approach to enhance the immunogenicity of DNA vaccines involving the use of transcription factors of the Interferon regulatory factor (IRF) family, specifically IRF-1, IRF-3, and IRF-7 using the tat gene as model antigen. Balb/c mice were immunized by three intramuscular inoculations, using a DNA prime-protein boost protocol, with a DNA encoding tat of HIV-1 and the indicated IRFs and immune responses were compared to those induced by vaccination with tat DNA alone. In vivo administration of plasmid DNA encoding IRF-1, or a mutated version of IRF-1 deleted of the DNA-binding domain, enhanced Tat-specific immune responses and shifted them towards a predominant T helper 1-type immune response with increased IFN-gamma production and cytotoxic T lymphocytes responses. Conversely, the use of IRF-3 or IRF-7 did not affect the tat-induced responses. These findings define IRF-1 and its mutated form as efficacious T helper 1-inducing adjuvants in the context of tat-based vaccination and also providing a new promising candidate for genetic vaccine development.

Hepatitis C virus (HCV) proteins are known to interfere at several levels with both innate and adaptive responses of the host. A key target in these effects is the interferon (IFN) signaling pathway. While the effects of nonstructural proteins are well established, the role of structural proteins remains controversial. We investigated the effect of HCV structural proteins on the expression of interferon regulatory factor 1 (IRF-1), a secondary transcription factor of the IFN system responsible for inducing several key antiviral and immunomodulatory genes. We found substantial inhibition of IRF-1 expression in cells expressing the entire HCV replicon. Suppression of IRF-1 synthesis was mainly mediated by the core structural protein and occurred at the transcriptional level. The core protein in turn exerted a transcriptional repression of several interferon-stimulated genes, targets of IRF-1, including interleukin-15 (IL-15), IL-12, and low-molecular-mass polypeptide 2. These data recapitulate in a unifying mechanism, i.e., repression of IRF-1 expression, many previously described pathogenetic effects of HCV core protein and suggest that HCV core-induced IRF-1 repression may play a pivotal role in establishing persistent infection by dampening an effective immune response.