Pathogenesis of Human Papillomavirus – Immunological Responses to HPV Infection

Papillomavirus is an oncogenic virus which infects mucosal and cutaneous epithelia where it induces benign hyperproliferative lesions. Few studies have been conducted on the causative factors associated with the development of cancer. Infections by high-risk human papillomaviruses (HPVs) have been implicated as causative agents in a variety of cancers such as anogenital, and head and neck cancers. HPVs appear to have evolved mechanisms resulting in escape from host immune surveillance and delay of resolution of infection. The HPV E5 oncoprotein is one of the possible effectors that allows the virus to escape from host immune system through the downregulation of surface classical major histocompatibility complex class I (MHC I) and not the nonclassical MHC I. Lack of classical MHC I in infected cells expressing E5 would allow evasion of cytotoxic T lymphocytes (CTLs) killing and thus establishment and persistence of viral infection

Similarities and differences between the E5 oncoproteins of bovine papillomaviruses type 1 and type 4: Cytoskeleton, motility and invasiveness in E5-transformed bovine and mouse cells

Bovine papillomaviruses (BPVs) are oncogenic viruses. In cattle, BPV-1/2 is associated with urinary bladder cancer and BPV-4 with upper GI tract cancer. BPV E5 is a small hydrophobic protein localised in the endoplasmic reticulum (ER) and Golgi apparatus (GA). E5 is the major transforming protein of BPVs, capable of inducing cell transformation in cultured mouse fibroblasts and, in cooperation with E7, in primary bovine cells. E5-induced cell transformation is accompanied by activation of several cellular protein kinases, including growth factor receptors, and alkalinisation of endosomes and GA. We have reported that BPV E5 causes swelling and fragmentation of the GA and extensive vacuolisation of the cytoplasm. We now show that E5 from both BPV-1 and BPV-4 disturbs the actin cytoskeleton and focal adhesions in transformed bovine cells, where these morphological and behavioural characteristics are accompanied by hyperphosphorylation of the cellular phosphotyrosine kinase c-src. Both BPV-1 and BPV-4 E5 increase the motility of transformed mouse cells, but only BPV-1 E5 causes transformed mouse cells to penetrate a matrigel matrix. BPV-1 transformed mouse cells, but not BPV-4 transformed mouse cells, have hyperhpsphorylated c-src

Review

Mitochondria are the main suppliers of neuronal adenosine triphosphate and play a critical role in brain energy metabolism. Mitochondria also serve as Ca2+ sinks and anabolic factories and are therefore essential for neuronal function and survival. Dysregulation of neuronal bioenergetics is increasingly implicated in neurodegenerative disorders, particularly Parkinson's disease. This review describes the role of mitochondria in energy metabolism under resting conditions and during synaptic transmission, and presents evidence for the contribution of neuronal mitochondrial dysfunction to Parkinson's disease

Mutational Analysis of the Transforming Protein E8 of Bovine Papillomavirus Type-4 (BPV-4)

The transforming genes of bovine papillomavirus type 4 (BPV-4) are encoded by the E7 and E8 open reading frames (ORFs). E7 is the transforming gene of BPV-4, in that, in co-operation with activated ras, it induces morphological transformation of primary bovine fibroblasts (PalF) in the absence of other viral genes, but the acquisition of anchorage independent growth requires the additional presence of E8. The BPV-4 E8 is a small transforming protein localized to cellular membrane. It consists of two domains: a very hydro'phobic region encompassing the first 30 amino acids of the protein, and a second region of mainly hydrophilic amino acids comprising the C terminal 12 residues. The results in this thesis demonstrated that in addition to the ability of E8 to grow independently of anchorage, PalF cells expressing E8 lose gap junction intercellular communication (GJIC), can grow in low serum, and are not contact inhibited. E8 also transactivates the cyclin A promoter in PalF cells. Mutant forms of E8 were generated to establish if the transforming functions of the protein could be segregated and therefore to define its functional domains. Mutations were introduced both in the hydrophobic domain and in the hydrophilic C-terminal tail, and chimeras with BPV-1 E5 were constructed. Cells expressing either E8 wild type or its mutants were analysed for their ability to: morphological transformation, anchorage independent growth, focus formation, cell population growth in low serum, tumorigenicity in nude mice, trans-activation of the cyclin A promoter, binding to ductin and down regulation of GJIC. The analysis of E8 mutants and chimeras constructed with BPV-1 E5 show that the multiple transforming function of E8 can be segregated and that both the hydrophobic domain and the hydrophilic C-terminal tail of E8 are critical for its functions and for the transactivation of the cyclin A promoter. These results support the hypothesis that the different aspects of cellular transformation produced by E8 might be due to interaction with different cellular targets. The observation from the analysis of the transformation parameters of E8 and BPV-1 E5 expressing cells suggest that E8 acts differently from E5. This study also demonstrates that the separate domains of E5 and E8 are not functionally interchangeable. The short term co-transfection analysis of E8 mutants suggest that substitution of alanine with proline, which is expected to alter the conformation of the hydrophobic domain, may have an effect on cell transformation. Also the short-term co-transfection experiments of E8 mutants in the putative casein kinase II site support the possibility that BPV-4 E8 might be phosphorylated by CKII and that this phosphorylation could have an effect on the biological activities of this protein

The quality of life in boys with Duchenne muscular dystrophy

We conducted a study to evaluate the quality of life in boys with Duchenne muscular dystrophy aged 8–18 years, compared with that in matched healthy controls. A total of 85 boys with Duchenne muscular dystrophy aged 8–18 years and 136 age, sex and living place matched healthy controls were included in this study. Patients and one of their parents separately completed the 27-item Persian version of KIDSCREEN questionnaire (child and adolescent version and parent version). From the children's perspective, the quality of life in patients was found to be lower in two subclasses: “physical activities and health” (p < 0.001) and “friends” (p = 0.005). Parental estimation of their sick child's quality of life was significantly lower than children's own assessment in two subclasses: “physical activities and health” (p < 0.001) and “general mood and feelings” (p < 0.001). Our results indicate that boys with Duchenne muscular dystrophy have quite a satisfactory quality of life. A happier and more hopeful life can be promoted through increasing social support and improving the parental knowledge regarding their child's more positive life perspective. © 2016 Elsevier B.V

Three rare cases of anthrax arising from the same source

Anthrax is an acute bacterial infection caused by Bacillus anthracis. Humans become infected under natural conditions by contact with infected animals or contaminated animal products. About 95% of human anthrax is cutaneous and 5% respiratory. Gastrointestinal anthrax is very rare, and has been reported in less than 1% of all cases. Anthrax meningitis is a rare complication of any of the other three forms of disease. We report three rare cases of anthrax (gastrointestinal, oropharyngeal and meningitis) arising from the same source. The three patients were from a single family and were admitted with different clinical pictures after the ingestion of half-cooked meat from a sick sheep. These cases emphasize the need for awareness of anthrax in the differential diagnosis in areas where the disease remains endemic

Two new root endophyte and nematode cyst parasite species of the widely distributed genus Laburnicola

Fungal root endophytes, including the common form group of dark septate endophytes (DSEs), represent different taxonomic groups with potentially diverse life strategies. During surveys of DSE communities and of nematode cysts colonizing fungi, isolates representing Laburnicola ( Didymosphaeriaceae , Pleosporales ) lineages were discovered. Here we carried out a comprehensive study of the phylogenetic relationships and taxonomy of fungi collected from plant roots in Hungary, Mongolia, and Kazakhstan and from eggs of the cereal cyst nematode Heterodera filipjevi in Turkey. In addition to the study of the morphology and culture characteristics of the strains, four loci (internal transcribed spacer, partial large and small subunit regions of nuclear ribosomal DNA and partial translation elongation factor 1-alpha) were used to infer the molecular phylogenetic relationships of the strains within Laburnicola . The isolates were found to represent two distinct lineages, which are described here as novel species, Laburnicola nematophila and L. radiciphila . The interaction of the strains with plants and nematodes was examined using in vitro bioassays, which revealed endophytic interactions with the plant roots and parasitic interactions with the nematode eggs. Analyses of similar ITS sequences found in public databases revealed that members of the genus Laburnicola are widely distributed characteristic members of the plant microbiome, and they are reported as parasites of plant parasitic cyst nematodes here for the first time

Varicella-Zoster viruses associated with post-herpetic neuralgia induce sodium current density increases in the ND7-23 Nav-1.8 neuroblastoma cell line

Post-herpetic neuralgia (PHN) is the most significant complication of herpes zoster caused by reactivation of latent Varicella-Zoster virus (VZV). We undertook a heterologous infection in vitro study to determine whether PHN-associated VZV isolates induce changes in sodium ion channel currents known to be associated with neuropathic pain. Twenty VZV isolates were studied blind from 11 PHN and 9 non-PHN subjects. Viruses were propagated in the MeWo cell line from which cell-free virus was harvested and applied to the ND7/23-Nav1.8 rat DRG x mouse neuroblastoma hybrid cell line which showed constitutive expression of the exogenous Nav 1.8, and endogenous expression of Nav 1.6 and Nav 1.7 genes all encoding sodium ion channels the dysregulation of which is associated with a range of neuropathic pain syndromes. After 72 hrs all three classes of VZV gene transcripts were detected in the absence of infectious virus. Single cell sodium ion channel recording was performed after 72 hr by voltage-clamping. PHN-associated VZV significantly increased sodium current amplitude in the cell line when compared with non-PHN VZV, wild-type (Dumas) or vaccine VZV strains ((POka, Merck and GSK). These sodium current increases were unaffected by acyclovir pre-treatment but were abolished by exposure to Tetrodotoxin (TTX) which blocks the TTX-sensitive fast Nav 1.6 and Nav 1.7 channels but not the TTX-resistant slow Nav 1.8 channel. PHN-associated VZV sodium current increases were therefore mediated in part by the Nav 1.6 and Nav 1.7 sodium ion channels. An additional observation was a modest increase in message levels of both Nav1.6 and Nav1.7 mRNA but not Nav 1.8 in PHN virally infected cells

Genome-Wide RNAi of C. elegans Using the Hypersensitive rrf-3 Strain Reveals Novel Gene Functions

RNA-mediated interference (RNAi) is a method to inhibit gene function by introduction of double-stranded RNA (dsRNA). Recently, an RNAi library was constructed that consists of bacterial clones expressing dsRNA, corresponding to nearly 90% of the 19,427 predicted genes of C. elegans. Feeding of this RNAi library to the standard wild-type laboratory strain Bristol N2 detected phenotypes for approximately 10% of the corresponding genes. To increase the number of genes for which a loss-of-function phenotype can be detected, we undertook a genome-wide RNAi screen using the rrf-3 mutant strain, which we found to be hypersensitive to RNAi. Feeding of the RNAi library to rrf-3 mutants resulted in additional loss-of-function phenotypes for 393 genes, increasing the number of genes with a phenotype by 23%. These additional phenotypes are distributed over different phenotypic classes. We also studied interexperimental variability in RNAi results and found persistent levels of false negatives. In addition, we used the RNAi phenotypes obtained with the genome-wide screens to systematically clone seven existing genetic mutants with visible phenotypes. The genome-wide RNAi screen using rrf-3 significantly increased the functional data on the C. elegans genome. The resulting dataset will be valuable in conjunction with other functional genomics approaches, as well as in other model organisms