http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2013 , Hindawi Publishing Corporation . All rights reserved. Sat, 18 May 2013 09:50:47 +0000 http://www.hindawi.com/isrn/virology/2013/609348/ Infection with HIV-1 continues to be a threat to public health. Successful antiretroviral therapy has reduced the risk of developing AIDS but cannot fully eradicate the virus due to latent proviral sequences remaining in infected cells. The 5′-long terminal repeat (LTR) of HIV-1 is critical for the regulation of transcription of the viral RNA and subsequent production of new viral particles. Indeed, the regulation of transcription relies upon the binding of host cell transcription factors and associated regulatory proteins to the LTR. Recently, it has been found that the treatment of cells with ligands of a number of nuclear receptors (NRs) resulted in inhibition of HIV-1 replication. This inhibition likely occurs via effects on other proteins that bind to the 5′-LTR, notably NF-κB. Here, the possible binding site of one NR, the peroxisome proliferator-activated receptor (PPAR), in the HIV-1 5′-LTR is analysed within isolates of the virus. Given the high mutation rate of HIV-1, it is striking that this region remains conserved in more recent isolates from geographically distinct regions. This work provides a rationale for further study of the binding site recognised by PPAR in the HIV-1 5′-LTR. Tara Hurst Copyright © 2013 Tara Hurst. All rights reserved. Mon, 29 Apr 2013 14:51:46 +0000 http://www.hindawi.com/isrn/virology/2013/898730/ Parvovirus B19 is a widespread human pathogenic virus, member of the Erythrovirus genus in the Parvoviridae family. Infection can be associated with an ample range of pathologies and clinical manifestations, whose characteristics and outcomes depend on the interplay between the pathogenetic potential of the virus, its adaptation to different cellular environments, and the physiological and immune status of the infected individuals. The scope of this review is the advances in knowledge on the biological characteristics of the virus and of virus-host relationships; in particular, the interactions of the virus with different cellular environments in terms of tropism and ability to achieve a productive replicative cycle, or, on the contrary, to establish persistence; the consequences of infection in terms of interference with the cell physiology; the process of recognition of the virus by the innate or adaptive immune system, hence the role of the immune system in controlling the infection or in the development of clinical manifestations. Linked to these issues is the continuous effort to develop better diagnostic algorithms and methods and the need for development of prophylactic and therapeutic options for B19V infections. Giorgio Gallinella Copyright © 2013 Giorgio Gallinella. All rights reserved. Thu, 14 Mar 2013 09:43:26 +0000 http://www.hindawi.com/isrn/virology/2013/834890/ Human herpesvirus (HHV-) 6A and HHV-6B are two distinct β-herpesviruses which have been associated with various neurological diseases, including encephalitis, meningitis, epilepsy, and multiple sclerosis. Although the reactivation of both viruses is recognized as the cause of some neurological complications in conditions of immunosuppression, their involvement in neuroinflammatory diseases in immunocompetent people is still unclear, and the mechanisms involved have not been completely elucidated. Here, we review the available data providing evidence for the capacity of HHV-6A and -6B to infect the central nervous system and to induce proinflammatory responses by infected cells. We discuss the potential role of both viruses in neuroinflammatory pathologies and the mechanisms which could explain virus-induced neuropathogenesis. Joséphine M. Reynaud and Branka Horvat Copyright © 2013 Joséphine M. Reynaud and Branka Horvat. All rights reserved. Sun, 09 Dec 2012 10:42:30 +0000 http://www.hindawi.com/isrn/virology/2013/709734/ Human enteric adenoviruses of species F, HAdV-40 and HAdV-41 (Ad40 and Ad41), are associated with gastroenteritis in children. Ad attachment to the primary receptor on the cell surface is mediated by the distal head domain of the fiber protein, an antenna-like component of the adenovirus capsid. Differently from the majority of human Ads that possess one type of fiber on their capsid, the Ad40 and 41 have two distinct fibers. The long fiber recognizes the host membrane protein CAR, which permits virus attachment, but nothing is known about the role of the short fiber. Using the head domain of the Ad41 short fiber, we fished out a putative membrane protein that has never been previously described. This partner of the short fiber of enteric Ad41 (ParAd41) is a small, hydrophobic protein with three putative trans membrane domains, which interacts with the Ad41 short fiber but not with the Ad41 long fiber or with the fiber of respiratory Ad2 serotype. ParAd41 is localized in intracellular membranes including the nuclear membrane. Saturation of the short fiber with ParAd41 inhibits virus infectivity, which substantiates the putative role of ParAd41 in enteric Ads tropism. It is conceivable that the interaction of the short fiber with ParAd41 mediates virus postattachment endocytosis step as well as interaction with the nuclear membrane prior to the injection of viral DNA into the nucleus, thus enabling enteric adenovirus infection. This study is the first one to probe the molecular nature of enteric Ad41 tropism. Anne-Laure Favier, Renata Grzela, Siergiej Tcherniuk, Marianna Charlotte Harsi, and Jadwiga Chroboczek Copyright © 2013 Anne-Laure Favier et al. All rights reserved. Tue, 04 Dec 2012 11:27:36 +0000 http://www.hindawi.com/isrn/virology/2013/861912/ Alphaviruses are enveloped single-stranded positive sense RNA viruses of the family Togaviridae. The genus alphavirus contains nine viruses, which are of medical, theoretical, or economic importance, and which will be considered. Sindbis virus (SINV) and Semliki Forest (SFV), although of some medical importance, have largely been studied as models of viral pathogenicity. In mice, SINV and SFV infect neurons in the central nervous system and virulent strains induce lethal encephalitis, whereas avirulent strains of SFV induce demyelination. SFV infects the developing foetus and can be teratogenic. Venezuelan Equine Encephalitis virus, Eastern Equine Encephalitis virus, and Western Equine Encephalitis virus can induce encephalitis in horses and humans. They are prevalent in the Americas and are mosquito transmitted. Ross River virus, Chikungunya virus (CHIKV), and O’nyong-nyong virus (ONNV) are prevalent in Australasia, Africa and Asia, and Africa, respectively. ONNV virus is transmitted by Anopheles mosquitoes, while the other alphaviruses are transmitted by culicine mosquitoes. CHIKV has undergone adaptation to a new mosquito host which has increased its host range beyond Africa. Salmonid alphavirus is of economic importance in the farmed salmon and trout industry. It is postulated that future advances in research on alphavirus pathogenicity will come in the field of innate immunity. Gregory J. Atkins Copyright © 2013 Gregory J. Atkins. All rights reserved. Tue, 04 Dec 2012 08:35:20 +0000 http://www.hindawi.com/isrn/virology/2013/306595/ The cell signaling plays a pivotal role in regulating cellular processes and is often manipulated by viruses as they rely on the functions offered by cells for their propagation. The first stage of their host life is to pass the genetic materials into the cell. Although some viruses can directly penetrate into cytosol, in fact, most virus entry into their host cells is through endocytosis. This machinery initiates with cell type specific cellular signaling pathways, and the signaling compounds can be proteins, lipids, and carbohydrates. The activation can be triggered in a very short time after virus binds on target cells, such as receptors. The signaling pathways involved in regulation of viral entry are wide diversity that often cross-talk between different endocytosis results. Furthermore, some viruses have the ability to use the multiple internalization pathways which leads to the regulation being even more complex. In this paper, we discuss some recent advances in our understanding of cellular pathways for virus entry, molecular signaling during virus entry, formation of endocytic vesicles, and the traffic. Pei-I Chi and Hung-Jen Liu Copyright © 2013 Pei-I Chi and Hung-Jen Liu. All rights reserved. Thu, 13 Sep 2012 14:04:11 +0000 http://www.hindawi.com/isrn/virology/2013/425831/ The Dominican Republic (DR) and Haiti share the island of Hispaniola, and reportable transboundary animal diseases have been introduced between the two countries historically. Outbreaks of severe teschovirus encephalomyelitis in pigs began occurring in Haiti in February 2009, and a field and laboratort study in April 2010 indicated that the teschovirus disease is prevalent in many regions in Haiti including areas near the border with DR and that other viral disease agents, including CSF virus (CSFV), porcine circovirus type 2 (PCV-2), porcine reproductive and respiratory syndrome virus (PRRSV), and swine influenza virus (SIV), are present in the swine population in these regions. The purpose of this study was to evaluate the introduction of teschovirus encephalomyelitis from Haiti to DR and to identify the other viral disease agents present in the swine population in regions of DR near the border with Haiti. Six of 7 brains and 6 of 7 spinal cords collected from pigs with central nervous system (CNS) signs were positive in reverse transcription-polymerase chain reaction for PTV. Genome sequencing on the Dominican PTV and phylogenetic analysis on the polyprotein of PTV strains indicate that the sequence of the Dominican PTV is 99.1% identical to the Haitian isolate and closely related to other PTV-1 strains in the world. Among 109 serum samples tested, 65 (59.6%) were positive for antibodies to PCV-2, and 51 (46.8%) were positive for antibodies to CSFV. Fifty-four of the 109 serum samples were tested for antibodies to other agents. Among the 54 samples, 20 (37.0%) were seropositive to PTV-1, 17 (31.5%) tested seropositive to SIV H3N2, 12 (22.2%) were seropositive to SIV H1N1, and 1 (1.9%) was seropositive to PRRSV. A. Ventura, W. Gonzalez, R. Barrette, S. Swenson, A. Bracht, J. Rowland, A. Fabian, K. Moran, F. Mohamed, E. O'Hearn, M. Jenkins-Moore, D. Toms, J. Shaw, P. Morales, D. Pyburn, C. Carrillo, G. Mayr, M. McIntosh, and M. Deng Copyright © 2013 A. Ventura et al. All rights reserved.