PMCC PMCC

Search tips
Search criteria

Advanced
Results 1-25 (107)
 

Clipboard (0)
None
Journals
Year of Publication
1.  Detection of Influenza Virus Infection Using Two PCR Methods 
Advances in Virology  2014;2014:274679.
Rapid, accurate, and cost-effective methods to identify the cause of respiratory tract infections are needed to maximize clinical benefit. Outpatients with acute respiratory illness were tested for influenza using a singleplex reverse transcriptase polymerase chain reaction (SRT-PCR) method. A multiplex RT-PCR (MRT-PCR) method tested for influenza and 17 other viruses and was compared with SRT-PCR using chi-square tests. Among 935 patients, 335 (36%) tested positive for influenza A and influenza B using SRT-PCR. Using MRT-PCR, 320 (34.2%) tested positive for influenza A and influenza B. This study supports MRT-PCR as a comparable method for detecting influenza among patients seeking outpatient care for acute respiratory illnesses.
doi:10.1155/2014/274679
PMCID: PMC4276355  PMID: 25574169
2.  Structural Differences Observed in Arboviruses of the Alphavirus and Flavivirus Genera 
Advances in Virology  2014;2014:259382.
Arthropod borne viruses have developed a complex life cycle adapted to alternate between insect and vertebrate hosts. These arthropod-borne viruses belong mainly to the families Togaviridae, Flaviviridae, and Bunyaviridae. This group of viruses contains many pathogens that cause febrile, hemorrhagic, and encephalitic disease or arthritic symptoms which can be persistent. It has been appreciated for many years that these viruses were evolutionarily adapted to function in the highly divergent cellular environments of both insect and mammalian phyla. These viruses are hybrid in nature, containing viral-encoded RNA and proteins which are glycosylated by the host and encapsulate viral nucleocapsids in the context of a host-derived membrane. From a structural perspective, these virus particles are macromolecular machines adapted in design to assemble into a packaging and delivery system for the virus genome and, only when associated with the conditions appropriate for a productive infection, to disassemble and deliver the RNA cargo. It was initially assumed that the structures of the virus from both hosts were equivalent. New evidence that alphaviruses and flaviviruses can exist in more than one conformation postenvelopment will be discussed in this review. The data are limited but should refocus the field of structural biology on the metastable nature of these viruses.
doi:10.1155/2014/259382
PMCID: PMC4182009  PMID: 25309597
3.  Molecular Characterization of Chicken Anemia Virus Circulating in Chicken Flocks in Egypt 
Advances in Virology  2014;2014:797151.
Introduction. Although many previous studies reported detection of chicken anemia virus (CAV) in Egypt since 1990, genomic characterization of this circulating CAV has not been published. In the present study, four nucleotide sequences of detected CAV were genetically characterized. Methods. These nucleotide sequences were obtained from commercial chicken flocks in two different locations of Egypt during 2010. The target region for sequencing was 675 bp nucleotide of partial coding region of VP1 protein. The nucleotide and deduced amino acid sequences of the detected CAV were aligned and compared to worldwide CAV isolates including commonly used vaccine strains. Phylogenetic analysis of these sequences was also carried out. Results. Our results showed that all the Egyptian CAV sequences were grouped in one group with viruses from diverse geographic regions. This group is characterized by amino acids profile 75I, 97L, 139Q, and 144Q in VP1. The phylogenetic and amino acid analyses of deduced amino acid indicated that the detected CAV sequences differ from CAV vaccine strains. Conclusion. This is the first report that describes molecular characterization of circulating CAV in Egypt. The study showed that the detected CAV, in Egypt are field viruses and unrelated to vaccine strains.
doi:10.1155/2014/797151
PMCID: PMC4180199  PMID: 25302064
4.  Appearance of L90I and N205S Mutations in Effector Domain of NS1 Gene of pdm (09) H1N1 Virus from India during 2009–2013 
Advances in Virology  2014;2014:861709.
In the present study, full length sequencing of NS gene was done in 91 samples which were obtained from patients over the time period of five years from 2009 to 2013. The sequencing of NS gene was undertaken in order to determine the changes/mutations taking place in the NS gene of A H1N1 pdm (09) since its emergence in 2009. Analysis has shown that the majority of samples belong to New York (G1 type) strain with valine at position 123. Effector domain of NS1 protein displays the appearance of three mutations L90I, I123V, and N205S in almost all the samples from 2010 onwards. Phylogenetic analysis of available NS1 sequences from India has grouped all the sequences into four clusters with mean genetic distance ranging from 12% to 24% between the clusters. Variability in length of NS1 protein was seen in sequences from these clusters, 230-amino-acid-residue NS1 for all strains from year 2007 to 2008 and for 21 strains from year 2009 and 219-residue products for 37 strains from year 2009 and all strains from year 2010 to 2013. Mutations like K62R, K131Q, L147R, and A202P were observed for the first time in NS1 protein and their function remains to be determined.
doi:10.1155/2014/861709
PMCID: PMC4181907  PMID: 25309598
5.  Influenza Virus Aerosols in the Air and Their Infectiousness 
Advances in Virology  2014;2014:859090.
Influenza is one of the most contagious and rapidly spreading infectious diseases and an important global cause of hospital admissions and mortality. There are some amounts of the virus in the air constantly. These amounts is generally not enough to cause disease in people, due to infection prevention by healthy immune systems. However, at a higher concentration of the airborne virus, the risk of human infection increases dramatically. Early detection of the threshold virus concentration is essential for prevention of the spread of influenza infection. This review discusses different approaches for measuring the amount of influenza A virus particles in the air and assessing their infectiousness. Here we also discuss the data describing the relationship between the influenza virus subtypes and virus air transmission, and distribution of viral particles in aerosol drops of different sizes.
doi:10.1155/2014/859090
PMCID: PMC4147198  PMID: 25197278
6.  Novel Gyroviruses, including Chicken Anaemia Virus, in Clinical and Chicken Samples from South Africa 
Advances in Virology  2014;2014:321284.
Introduction. Chicken anaemia virus, CAV, was until recently the only member of the Gyrovirus genus. 6 novel gyroviruses, AGV2, HGyV1, and GyV3-6, have since been discovered in human and chicken samples. Methods. PCR amplification of the VP2 gene was used to detect AGV2/HGyV1, GyV3, and CAV in a range of clinical samples including stool, respiratory, CSF, and HIV-positive plasma. Screening of fresh local chicken meat was also performed. Results. AGV2/HGyV1 or GyV3 was detected in stools from healthy children (17/49, 34.7%) and patients with diarrhoea (22/149, 14.8%). 1.2% (3/246) nasopharyngeal respiratory samples were positive. No AGV2/HGyV1 or GyV3 was detected in nasal swabs from wheezing patients, in CSF from patients with meningitis, and in HIVpositive plasma. CAV was found in 51% (25/49) of stools from healthy children and 16% (24/149) in diarrhoea samples. Screening of 28 chicken samples showed a higher prevalence of gyrovirus (20/28, 71%) compared to CAV (1/28, 3.6%). Phylogenetic analysis of the CAV VP1 gene showed South African sequences clustering with Brazilian isolates from genotypes D2 and A2. Conclusion. Novel gyroviruses, including CAV, are present in the South African population with diarrhoea and respiratory illness as well as in healthy children. Their presence suggests an origin from chicken meat consumption.
doi:10.1155/2014/321284
PMCID: PMC4022007  PMID: 24876841
7.  Screening of Viral Pathogens from Pediatric Ileal Tissue Samples after Vaccination 
Advances in Virology  2014;2014:720585.
In 2010, researchers reported that the two US-licensed rotavirus vaccines contained DNA or DNA fragments from porcine circovirus (PCV). Although PCV, a common virus among pigs, is not thought to cause illness in humans, these findings raised several safety concerns. In this study, we sought to determine whether viruses, including PCV, could be detected in ileal tissue samples of children vaccinated with one of the two rotavirus vaccines. A broad spectrum, novel DNA detection technology, the Lawrence Livermore Microbial Detection Array (LLMDA), was utilized, and confirmation of viral pathogens using the polymerase chain reaction (PCR) was conducted. The LLMDA technology was recently used to identify PCV from one rotavirus vaccine. Ileal tissue samples were analyzed from 21 subjects, aged 15–62 months. PCV was not detected in any ileal tissue samples by the LLMDA or PCR. LLMDA identified a human rotavirus A from one of the vaccinated subjects, which is likely due to a recent infection from a wild type rotavirus. LLMDA also identified human parechovirus, a common gastroenteritis viral infection, from two subjects. Additionally, LLMDA detected common gastrointestinal bacterial organisms from the Enterobacteriaceae, Bacteroidaceae, and Streptococcaceae families from several subjects. This study provides a survey of viral and bacterial pathogens from pediatric ileal samples, and may shed light on future studies to identify pathogen associations with pediatric vaccinations.
doi:10.1155/2014/720585
PMCID: PMC3980782  PMID: 24778651
8.  Characterization of the Protective HIV-1 CTL Epitopes and the Corresponding HLA Class I Alleles: A Step towards Designing CTL Based HIV-1 Vaccine 
Advances in Virology  2014;2014:321974.
Human immunodeficiency virus (HIV) possesses a major threat to the human life largely due to the unavailability of an efficacious vaccine and poor access to the antiretroviral drugs against this deadly virus. High mutation rate in the viral genome underlying the antigenic variability of the viral proteome is the major hindrance as far as the antibody based vaccine development is concerned. Although the exact mechanism by which CTL epitopes and the restricting HLA alleles mediate their action towards slow disease progression is still not clear, the important CTL restricted epitopes for controlling viral infections can be utilized in future vaccine design. This study was designed for the characterization the HIV-1 optimal CTL epitopes and their corresponding HLA alleles. CTL epitope cluster distribution analysis revealed only two HIV-1 proteins, namely, Nef and Gag, which have significant cluster forming capacity. We have found the role of specific HLA supertypes such as HLA B∗07, HLA B∗58, and HLA A∗03 in selecting the hydrophobic and conserved amino acid positions within Nef and Gag proteins, to be presented as epitopes. The analyses revealed that the clusters of optimal epitopes for Nef and p24 proteins of HIV-1 could potentially serve as a source of vaccine.
doi:10.1155/2014/321974
PMCID: PMC3976937  PMID: 24744786
10.  Genotyping of HCV RNA Reveals That 3a Is the Most Prevalent Genotype in Mardan, Pakistan 
Advances in Virology  2014;2014:606201.
The clinical outcomes of patients infected with hepatitis C virus (HCV) range from acute resolving hepatitis to chronic liver diseases such as liver cirrhosis or hepatocellular carcinoma. Identification of the infecting virus genotype is indispensable for the exploration of many aspects of HCV infection, including epidemiology, pathogenesis, and response to antiviral therapy. 1419 individuals were screened for anti-HCV in this study, of which 166 (11.7%) were found reactive by ICT (Immunochromatographic test). These 166 anti-HCV positive and 26 normal individuals were further analyzed. RNA was extracted from serum and reverse-transcribed to cDNA and the core region of HCV genome was targeted and amplified by multiplex PCR. HCV RNA was detected in 121 individuals, of which 87 were male and 34 were female. Genotype 3a was the most prevalent among all the genotypes observed followed by 3b. Genotypes 1a, 2a, and 2b were found in 10.89%, 13.22%, and 6.61% patients, respectively. 25.41% of the HCV RNA positive samples were not typed. 6.05% of patients were found having mixed genotypes. These findings will not only help the physicians to prescribe more appropriate treatment for the HCV infection but will also draw the attention of health-related policy makers to devise strategies to curb the disease more effectively.
doi:10.1155/2014/606201
PMCID: PMC3955652  PMID: 24715902
11.  Mutations in the H, F, or M Proteins Can Facilitate Resistance of Measles Virus to Neutralizing Human Anti-MV Sera 
Advances in Virology  2014;2014:205617.
Although there is currently no evidence of emerging strains of measles virus (MV) that can resist neutralization by the anti-MV antibodies present in vaccinees, certain mutations in circulating wt MV strains appear to reduce the efficacy of these antibodies. Moreover, it has been hypothesized that resistance to neutralization by such antibodies could allow MV to persist. In this study, we use a novel in vitro system to determine the molecular basis of MV's resistance to neutralization. We find that both wild-type and laboratory strain MV variants that escape neutralization by anti-MV polyclonal sera possess multiple mutations in their H, F, and M proteins. Cytometric analysis of cells expressing viral escape mutants possessing minimal mutations and their plasmid-expressed H, F, and M proteins indicates that immune resistance is due to particular mutations that can occur in any of these three proteins that affect at distance, rather than directly, the native conformation of the MV-H globular head and hence its epitopes. A high percentage of the escape mutants contain mutations found in cases of Subacute Sclerosing Panencephalitis (SSPE) and our results could potentially shed light on the pathogenesis of this rare fatal disease.
doi:10.1155/2014/205617
PMCID: PMC3932291  PMID: 24648840
12.  Recent Advances in Diagnosis, Prevention, and Treatment of Human Respiratory Syncytial Virus 
Advances in Virology  2013;2013:595768.
Human respiratory syncytial virus (RSV) is a common cause of respiratory infection in infants and the elderly, leading to significant morbidity and mortality. The interdisciplinary fields, especially biotechnology and nanotechnology, have facilitated the development of modern detection systems for RSV. Many anti-RSV compounds like fusion inhibitors and RNAi molecules have been successful in laboratory and clinical trials. But, currently, there are no effective drugs for RSV infection even after decades of research. Effective diagnosis can result in effective treatment, but the progress in both of these facets must be concurrent. The development in prevention and treatment measures for RSV is at appreciable pace, but the implementation into clinical practice still seems a challenge. This review attempts to present the promising diverse research approaches and advancements in the area of diagnosis, prevention, and treatment that contribute to RSV management.
doi:10.1155/2013/595768
PMCID: PMC3872095  PMID: 24382964
13.  Emergence of Hepatitis B Virus Genotype F in Aligarh Region of North India 
Advances in Virology  2013;2013:846849.
Introduction. HBV genotypes and subtypes are useful clinical and epidemiological markers. In this study prevalent HBV genotypes were assessed in relation to serological profile and clinical status. Material & Methods. 107 cases of HBV were genotyped. Detailed clinical history was elicited from them. HBsAg, HBeAg, anti-HBs, anti-HBe, and anti-HBc-IgM were assessed. HBV genotyping was performed using Kirschberg's type specific primers (TSP-PCR), heminested PCR, and Naito's monoplex PCR. Nucleotide sequencing was performed. Results. A total of 97 (91%) were genotyped following the methods of Kirschberg et al./Naito et al. Genotype D was by far the most prevalent genotype 91 (85.04%) in this region. A surprising finding was the detection of genotype F in 5 (4.67%) of our patients. Genotype A strangely was observed only in one case. In 85.7% genotype D was associated with moderate to severe liver disease, 43.9% HBeAg, and 18.7% anti-HBc-IgM positivity. Majority of genotype F (80%) was seen in mild to moderate liver disease. It was strongly associated with HBeAg 60% and 20% anti-HBc-IgM positivity. Conclusion. Emergence of genotype F in India merits further study regarding its clinical implications and treatment modalities. Knowledge about HBV genotypes can direct a clinician towards more informed management of HBV patients.
doi:10.1155/2013/846849
PMCID: PMC3870090  PMID: 24381592
14.  Elucidating the Interacting Domains of Chandipura Virus Nucleocapsid Protein 
Advances in Virology  2013;2013:594319.
The nucleocapsid (N) protein of Chandipura virus (CHPV) plays a crucial role in viral life cycle, besides being an important structural component of the virion through proper organization of its interactions with other viral proteins. In a recent study, the authors had mapped the associations among CHPV proteins and shown that N protein interacts with four of the viral proteins: N, phosphoprotein (P), matrix protein (M), and glycoprotein (G). The present study aimed to distinguish the regions of CHPV N protein responsible for its interactions with other viral proteins. In this direction, we have generated the structure of CHPV N protein by homology modeling using SWISS-MODEL workspace and Accelrys Discovery Studio client 2.55 and mapped the domains of N protein using PiSQRD. The interactions of N protein fragments with other proteins were determined by ZDOCK rigid-body docking method and validated by yeast two-hybrid and ELISA. The study revealed a unique binding site, comprising of amino acids 1–30 at the N terminus of the nucleocapsid protein (N1) that is instrumental in its interactions with N, P, M, and G proteins. It was also observed that N2 associates with N and G proteins while N3 interacts with N, P, and M proteins.
doi:10.1155/2013/594319
PMCID: PMC3830837  PMID: 24288532
15.  Viruses as Modulators of Mitochondrial Functions 
Advances in Virology  2013;2013:738794.
Mitochondria are multifunctional organelles with diverse roles including energy production and distribution, apoptosis, eliciting host immune response, and causing diseases and aging. Mitochondria-mediated immune responses might be an evolutionary adaptation by which mitochondria might have prevented the entry of invading microorganisms thus establishing them as an integral part of the cell. This makes them a target for all the invading pathogens including viruses. Viruses either induce or inhibit various mitochondrial processes in a highly specific manner so that they can replicate and produce progeny. Some viruses encode the Bcl2 homologues to counter the proapoptotic functions of the cellular and mitochondrial proteins. Others modulate the permeability transition pore and either prevent or induce the release of the apoptotic proteins from the mitochondria. Viruses like Herpes simplex virus 1 deplete the host mitochondrial DNA and some, like human immunodeficiency virus, hijack the host mitochondrial proteins to function fully inside the host cell. All these processes involve the participation of cellular proteins, mitochondrial proteins, and virus specific proteins. This review will summarize the strategies employed by viruses to utilize cellular mitochondria for successful multiplication and production of progeny virus.
doi:10.1155/2013/738794
PMCID: PMC3821892  PMID: 24260034
16.  Hepatitis Delta Virus: A Peculiar Virus 
Advances in Virology  2013;2013:560105.
The hepatitis delta virus (HDV) is distributed worldwide and related to the most severe form of viral hepatitis. HDV is a satellite RNA virus dependent on hepatitis B surface antigens to assemble its envelope and thus form new virions and propagate infection. HDV has a small 1.7 Kb genome making it the smallest known human virus. This deceivingly simple virus has unique biological features and many aspects of its life cycle remain elusive. The present review endeavors to gather the available information on HDV epidemiology and clinical features as well as HDV biology.
doi:10.1155/2013/560105
PMCID: PMC3807834  PMID: 24198831
17.  The Possible Role of TLR2 in Chronic Hepatitis B Patients with Precore Mutation 
Advances in Virology  2013;2013:780319.
Recognition mechanisms of innate immune response help to improve immunotherapeutic strategies in HBeAg-negative chronic hepatitis B (CHB). Toll-like receptor 2 (TLR2) is an important component of innate immunity. In this study, the frequency of precore mutations of the hepatitis B virus (HBV) and serum TLR2 were evaluated in CHB patients. Fifty-one patients with chronic hepatitis B, negative for HBeAg and detectable HBV DNA, were examined for the presence of mutations in pre-core region of HBV genome by direct sequencing. Serum TLR2 was measured by enzyme-linked immunosorbent assay. Interactions of truncated HBeAg and TLR2 proteins were evaluated with molecular docking software. The G1896A pre-core mutation were detected in 29 (57%) which was significantly associated with higher concentration of serum TLR2 in comparison with patients without this mutation (4.8 ± 2.9 versus 3.4 ± 2.2 ng/mL, P = 0.03). There was also a significant correlation between serum ALT and TLR-2 (r = 0.46; P = 0.01). Docking results illustrated residues within the N-terminus of truncated HBeAg and TLR2, which might facilitate the interaction of these proteins. These findings showed the dominance of G1896A pre-core mutation of HBV variants in this community which was correlated with serum TLR2. Moreover TLR2 is critical for induction of inflammatory cytokines and therefore ALT elevation.
doi:10.1155/2013/780319
PMCID: PMC3800624  PMID: 24187552
18.  Production of Platinum Atom Nanoclusters at One End of Helical Plant Viruses 
Advances in Virology  2013;2013:746796.
Platinum atom clusters (Pt nanoparticles, Pt-NPs) were produced selectively at one end of helical plant viruses, tobacco mosaic virus (TMV) and potato virus X (PVX), when platinum coordinate compounds were reduced chemically by borohydrides. Size of the platinum NPs depends on conditions of the electroless deposition of platinum atoms on the virus. Results suggest that the Pt-NPs are bound concurrently to the terminal protein subunits and the 5′ end of encapsidated TMV RNA. Thus, a special structure of tobacco mosaic virus and potato X virus particles with nanoparticles of platinum, which looks like a push-pin with platinum head and virus needle, was obtained. Similar results were obtained with ultrasonically fragmented TMV particles. By contrast, the Pt-NPs fully filled the central axial hole of in vitro assembled RNA-free TMV-like particles. We believe that the results presented here will be valuable in the fundamental understanding of interaction of viral platforms with ionic metals and in a mechanism of nanoparticles formation.
doi:10.1155/2013/746796
PMCID: PMC3800660  PMID: 24187551
19.  Recombinant Varicella-Zoster Virus Vaccines as Platforms for Expression of Foreign Antigens 
Advances in Virology  2013;2013:219439.
Varicella-zoster virus (VZV) vaccines induce immunity against childhood chickenpox and against shingles in older adults. The safety, efficacy, and widespread use of VZV vaccines suggest that they may also be effective as recombinant vaccines against other infectious diseases that affect the young and the elderly. The generation of recombinant VZV vaccines and their evaluation in animal models are reviewed. The potential advantages and limitations of recombinant VZV vaccines are addressed.
doi:10.1155/2013/219439
PMCID: PMC3697282  PMID: 23843791
20.  Safety and Efficacy of Hepatitis B Vaccination in Cirrhosis of Liver 
Advances in Virology  2013;2013:196704.
Introduction. Patients with chronic liver disease (CLD) are more likely to have severe morbidity and fatality rate due to superimposed acute or chronic hepatitis B (HBV) infection. The literature has shown that hepatitis B vaccines are safe and effective in patients with CLD, but the data in cirrhosis liver is lacking. We assessed the safety and immunogenicity of HBV vaccine in patients with cirrhosis liver. Methods. CTP classes A and B CLD patients negative for hepatitis B surface antigen and antibody to hepatitis B core antigen were included. All patients received three doses of hepatitis B vaccine 20 mcg intramuscularly at 0, 30, and 60 days. Anti-HBs antibody was measured after 120 days. Results. 52 patients with mean age 47.48 ± 9.37 years were studied. Response rates in CTP classes A and B were 88% and 33.3%. We observed that the alcoholic chronic liver disease had less antibody response (44%) than other causes of chronic liver disease such as cryptogenic 69% and HCV 75%. Conclusions. Patients with cirrhosis liver will have low antibody hepatitis B titers compared to general population. As the age and liver disease progress, the response rate for hepatitis B vaccination will still remain to be weaker.
doi:10.1155/2013/196704
PMCID: PMC3690205  PMID: 23840211
21.  Virus Entry by Endocytosis 
Advances in Virology  2013;2013:469538.
doi:10.1155/2013/469538
PMCID: PMC3654661  PMID: 23710180
22.  Transmitted Drug Resistance among People Living with HIV/Aids at Major Cities of Sao Paulo State, Brazil 
Advances in Virology  2013;2013:878237.
Human immunodeficiency virus type 1 (HIV-1) transmitted drug resistance (TDR) is an important public health issue. In Brazil, low to intermediate resistance levels have been described. We assessed 225 HIV-1 infected, antiretroviral naïve individuals, from HIV Reference Centers at two major metropolitan areas of Sao Paulo (Sao Paulo and Campinas), the state that concentrates most of the Brazilian Aids cases. TDR was analyzed by Stanford Calibrated Population Resistance criteria (CPR), and mutations were observed in 17 individuals (7.6%, 95% CI: 4.5%–11.9%). Seventy-six percent of genomes (13/17) with TDR carried a nonnucleoside reverse transcriptase inhibitor (NNRTI) resistance mutation, mostly K103N/S (9/13, 69%), potentially compromising the preferential first-line therapy suggested by the Brazilian HIV Treatment Guideline that recommends efavirenz-based combinations. Moreover, 6/17 (35%) had multiple mutations associated with resistance to one or more classes. HIV-1 B was the prevalent subtype (80%); other subtypes include HIV-1 F and C, mosaics BC, BF, and single cases of subtype A1 and CRF02_AG. The HIV Reference Center of Campinas presented more cases with TDR, with a significant association of TDR with clade B infection (P < 0.05).
doi:10.1155/2013/878237
PMCID: PMC3562575  PMID: 23401688
23.  Cellular Factors Implicated in Filovirus Entry 
Advances in Virology  2013;2013:487585.
Although filoviral infections are still occurring in different parts of the world, there are no effective preventive or treatment strategies currently available against them. Not only do filoviruses cause a deadly infection, but they also have the potential of being used as biological weapons. This makes it imperative to comprehensively study these viruses in order to devise effective strategies to prevent the occurrence of these infections. Entry is the foremost step in the filoviral replication cycle and different studies have reported the involvement of a myriad of cellular factors including plasma membrane components, cytoskeletal proteins, endosomal components, and cytosolic factors in this process. Signaling molecules such as the TAM family of receptor tyrosine kinases comprising of Tyro3, Axl, and Mer have also been implicated as putative entry factors. Additionally, filoviruses are suggested to bind to a common receptor and recent studies have proposed T-cell immunoglobulin and mucin domain 1 (TIM-1) and Niemann-Pick C1 (NPC1) as potential receptor candidates. This paper summarizes the existing literature on filoviral entry with a special focus on cellular factors involved in this process and also highlights some fundamental questions. Future research aimed at answering these questions could be very useful in designing novel antiviral therapeutics.
doi:10.1155/2013/487585
PMCID: PMC3556833  PMID: 23365575
24.  Influenza A Virus Entry: Implications in Virulence and Future Therapeutics 
Advances in Virology  2013;2013:121924.
Influenza A viruses have broad host tropism, being able to infect a range of hosts from wild fowl to swine to humans. This broad tropism makes highly pathogenic influenza A strains, such as H5N1, potentially dangerous to humans if they gain the ability to jump from an animal reservoir to humans. How influenza A viruses are able to jump the species barrier is incompletely understood due to the complex genetic nature of the viral surface glycoprotein, hemagglutinin, which mediates entry, combined with the virus's ability to use various receptor linkages. Current therapeutics against influenza A include those that target the uncoating process after entry as well as those that prevent viral budding. While there are therapeutics in development that target entry, currently there are none clinically available. We review here the genetics of influenza A viruses that contribute to entry tropism, how these genetic alterations may contribute to receptor usage and species tropism, as well as how novel therapeutics can be developed that target the major surface glycoprotein, hemagglutinin.
doi:10.1155/2013/121924
PMCID: PMC3556402  PMID: 23365574

Results 1-25 (107)