Molecular Phylogeny of Suid Herpesvirus 1

Pseudorabies is a disease that significantly impacts the swine industry. This disease is caused by Suid Herpesvirus 1 (SuHV-1), which is a double-stranded DNA virus that belongs to the Herpesviridae family and the Alphaherpesvirinae subfamily and exhibits a slow rate of genetic evolution. The aim of this study was to use both full and partial sequences of SuHV-1 genes available in GenBank to examine the evolution and divergence of viruses isolated in different parts of the world. Partial and complete sequences of SuHV-1 genes were obtained either from GenBank (i.e., us6, us7, us8, us9, ul14, ul49.5, and ul44) or from genetic sequencing of Brazilian SuHV-1 samples. The results of this study corroborate previous phylogenetic studies of SuHV-1 that demonstrated different evolutionary profiles of isolates from different parts of the globe, with a rapid genetic dispersion of Chinese isolates. All of the phylogenetic trees generated in this study demonstrated a large genetic distance between SuHV-1 isolates from the Western and Eastern regions of the world.

HIV-1 Tropism Test Evaluation: Assessment and Clinical Implications

CCR5 and CXCR4 chemokines receptors are critical coreceptors for the binding of HIV to specific host cells. Guidelines recommend its assessment in case of virological failure or before prescription of CCR5 inhibitors. Strategies to assess viral tropism may be divided into phenotypic and genotypic assays; registrative trials of CCR5 inhibitors used phenotypic assay, but recently genotypic ones have been used in clinical practice. The presence of CXCR4 is increasing in naïve patients, with both acute and chronic HIV-1 infections; this coreceptor usage is associated with CD4 depletion. The assessment of viral tropism should be considered in every stage of HIV-1 infection.

The Mre11 Cellular Protein Is Modified by Conjugation of Both SUMO-1 and SUMO-2/3 during Adenovirus Infection

The adenovirus type 5 (Ad5) E1B 55 kDa and E4 Orf6 proteins assemble a Cullin 5-E3 ubiquitin (Ub) ligase that targets, among other cellular proteins, p53 and the Mre11-Rad50-Nbs1 (MRN) complex for degradation. The latter is also inhibited by the E4 Orf3 protein, which promotes the recruitment of Mre11 into specific nuclear sites to promote viral DNA replication. The activities associated with the E1B 55 kDa and E4 Orf6 viral proteins depend mostly on the assembly of this E3-Ub ligase. However, E1B 55 kDa can also function as an E3-SUMO ligase, suggesting not only that regulation of cellular proteins by these viral early proteins may depend on polyubiquitination and proteasomal degradation but also that SUMOylation of target proteins may play a key role in their activities. Since Mre11 is a target of both the E1B/E4 Orf6 complex and E4 Orf3, we decided to determine whether Mre11 displayed similar properties to those of other cellular targets, in Ad5-infected cells. We have found that during Ad5-infection, Mre11 is modified by SUMO-1 and SUMO-2/3 conjugation. Unexpectedly, SUMOylation of Mre11 is not exclusively dependent on E1B 55 kDa, E4 Orf6, or E4 Orf3, rather it seems to be influenced by a molecular interplay that involves each of these viral early proteins.

Interaction of Hepatitis C Viral Proteins with Cellular Oncoproteins in the Induction of Liver Cancer

Hepatitis C virus infection is a major health problem all over the world. A large proportion of patients infected by HCV develop liver cirrhosis or cancer. However, the mechanism(s) remain to be elucidated. Since HCV does not carry any known oncogene, it is thought that interaction between virally encoded proteins and host proteins is responsible for carcinogenesis. Many crucial interactions between HCV-encoded proteins and host proteins have been reported. In this review we focus on the interaction of viral proteins with important regulators of cell cycle—oncoproteins YB-1, p53, and cyclin D1—which play a major role in cell proliferation, apoptosis, DNA repair, and genomic stability. Genetic variants of HCV accumulate in patients and alter these interactions of host cell proteins. It is a battle between the virus and host and the final outcome depends on the winner; if the host succeeds in clearing the virus the patient may not develop serious liver diseases. On the other hand, if the virus dominates by evolving quasispecies which code for altered proteins that interact differently with host proteins, or induce mutations in host protooncogenes, then the patient may develop liver cirrhosis and/or liver cancer.

In Silico Studies on Development of Novel Virostatic Agents against Bluetongue Virus

The core of BTV is organized into three concentric structures of which VP7 protein forms the major core protein. The subcore consists of VP3 protein and the innermost part of the core is made of three minor proteins: VP1, VP4, and VP6. Earlier it was reported that core-like particles (CLPs) composed of viral VP7 and VP3 proteins were produced in order to study role of VP7 protein in intermolecular interactions in the BTV assembly process. Site specific mutational studies revealed that substitution of the single lysine residue of VP7 (Lys-255) by leucine abrogated CLP formation, indicating a critical role for this lysine. In the present study, homology modeling, mutagenesis, and docking studies were carried out in order to design potent leads in modulation of VP7 protein in abrogating CLP formation.

The Genomic and Pathogenic Characteristics of the Highly Pathogenic Porcine Reproductive and Respiratory Syndrome Virus Isolate WUH2

To fully understand the extent of genetic diversity and pathogenesis of the highly pathogenic PRRSV found in China, we determined the genomic sequence of PRRSV WUH2; the pathogenicity of WUH2 was compared to the classical PRRSV isolate CH-1a. Our results showed that the WUH2 genome had a discontinuous deletion of 30 aa in Nsp2, a 1 nucleotide deletion located in both the 5′ and 3′ UTRs, and point mutations within GP5. Experimental infection demonstrated that PRRSV WUH2 reproduced the phenotype and symptoms of porcine high fever syndrome. Importantly, we found that there were differences in viral burden in the serum and tissues when comparing infections of the pathogenic isolate WUH2 to those of the classical isolate CH-1a. These data provide insight into the genomic diversity and altered pathogenicity of Chinese PRRSV isolates and help elucidate the evolution and potential pathogenic mechanisms of PRRSV.

Construction and Characterization of Recombinant HSV-1 Expressing Early Growth Response-1

Early Growth response-1 (Egr-1) is a transcription factor that possesses a variety of biological functions. It has been shown to regulate HSV-1 gene expression and replication in different cellular environments through the recruitment of distinct cofactor complexes. Previous studies demonstrated that Egr-1 can be induced by HSV-1 infection in corneal cells but the level was lower compared to other cell types. The primary goal of this report is to generate a recombinant HSV-1 constitutively expressing Egr-1 and to investigate the regulation of viral replication in different cell types or in animals with Egr-1 overexpression. The approach utilized was to introduce Egr-1 into the BAC system containing complete HSV-1 (F) genome. To assist in the insertion of Egr-1, a gene cassette was constructed that contains the Egr-1 gene flanked by loxP sites. In this clone Egr-1 is expressed under control of CMV immediate-early promoter followed by another gene cassette expressing the enhanced green fluorescent protein (EGFP) under the control of the elongation factor 1α (EF-1 α) promoter. The constructed recombinant viruses were completed containing the Egr-1 gene within the viral genome and the expression was characterized by qRT-PCR and Western blot analyses. Our results showed that Egr-1 transcript and protein can be generated and accumulated upon infection of recombinant virus in Vero and rabbit corneal cells SIRC. This unique virus therefore is useful for studying the effects of Egr-1 during HSV-1 replication and gene regulation in epithelial cells and neurons.

Electropherotypes and G-Types of Group A Rotaviruses Detected in Children with Diarrhea in Lagos, Nigeria

Approximately over 500,000 children die annually due to severe dehydrating diarrhea caused by rotaviruses. This work investigated rotavirus infection among children less than 5 years with diarrhea in Lagos and determined the circulating electropherotypes and genotypes of the virus isolates. Three hundred and two (n=302) stool samples from children below 60 months were collected from different hospitals and health care centers in Lagos and subjected to enzyme immunoassay (EIA) to determine the presence of Group A rotavirus, RT-PCR to determine the G-types, and polyacrylamide gel electrophoresis (PAGE) to determine the electropherotypes. The results show that 60.3% of the samples showed distinct rotavirus RNA migration pattern, having long electropherotypes (55.3%) of seven variations dominating over the short electropherotypes (44.5%). Six different G-types were detected (G1, G2, G3, G4, G9, and G12). Serotypes G1 and G12 showed long electropherotypic pattern while G2, G3, and G9 exhibited either short or long electropherotype. All G4 detected show short electropherotypic pattern. In conclusion, information on the genomic diversity and RNA electropherotypes of rotaviruses detected in children with diarrhea in Lagos is reported in this study.

HPV Prevalence and Detection of Rare HPV Genotypes in Hong Kong Women from Southern China with Cytological Abnormalities

Human papillomavirus (HPV) has been identified as the primary cause of cervical squamous intraepithelial lesion and invasive cervical cancer. The emergence of various commercial HPV genotyping kits with different characteristics facilitates the detection of most high-risk and low-risk HPV genotypes, but the rare HPV types are usually underdiagnosed. In the present study, HPV detection was performed using the GenoFlow HPV Array Test kit (DiagCor Bioscience), which can identify 33 HPV subtypes by specific probes. Besides, a HPV consensus probe (universal probe) was designed to capture not only the 33 genotypes but also rare subtypes. Of the 1643 Southern Chinese women tested between 2012 and 2013, the HPV prevalence was 42.3%, with HPV 52 (139/1643, 8.5%), HPV 81 (89/1643, 5.4%), and HPV 16 (63/1643, 3.8%) being the most frequent subtypes detected. Among all 695 HPV-positive cases, 56 (8.1%) cases were only detected by the universal probe, in which 5 were either ASCUS or LSIL cases. Sequencing results confirmed HPV types 30, 91, and 74, and the intratypic variants of HPV 72 and 82 were present in the 5 cases. The result suggests that some rare HPV subtypes might be involved in cervical lesions.