实验动物技术

Small interfering RNAs (siRNAs) and short hairpin RNAs (shRNAs) have been reported to suppress gene expression significantly. HCV seems a suitable candidate for targets of siRNAs, as HCV is a positive single-strand RNA virus and replicates in the cytoplasm. Efficient inhibition by siRNAs ...

NS5A phosphorylation can be studied in two ways: in living cells and in vitro. The former has several advantages: NS5A phosphorylation takes place in a cellular background and therefore might mimic more closely the real in vivo situation. Viral proteins and cellular kinases are in the correct ce ...

The NS5A protein of HCV is an essential component of the viral RNA replication machinery and may also function in modulation of the host cell environment. The exact function of NS5A in these processes remains unknown. NS5A is a large hydrophilic phosphoprotein protein consisting of three doma ...

HCV is a small positive-strand RNA virus responsible for a considerable proportion of acute and chronic hepatitis in humans. Although all HCV enzymes are, in theory, equally appropriate for therapeutic intervention, the NS3-NS4A serine protease and the NS5B RNA-dependent RNA polymer ...

After attachment to specific receptors on the surfaces of target cells, hepatitis C virus (HCV) particles are thought to be internalized to endosomes, where low pH induces fusion between the viral and cellular membranes, delivering the HCV genome into the cytoplasm. Here, we describe methods ...

HCV infection leads in 50 to 80% of cases to chronic hepatitis, liver cirrhosis, or hepatocellular carcinoma. Interferons and the nucleoside analog ribavirin form the basis for treatment but are not sufficiently effective and have numerous side effects. Although about 300 million people ...

This provides a brief introduction into the mechanism of DNA replication by the E1 and E2 proteins and describes the traditional Southern blotting technique that is used to monitor E1- and E2-mediated DNA replication. It also includes a novel real-time polymerase chain reaction (PCR) appro ...

Heterologous gene expression is often treated empirically and a number of host organisms are systematically tested. Early successes in the expression of recombinant proteins were achieved using the well-studied bacterium Escherichia coli (1). This prokaryotic expression sys ...

In addition to its involvement in clinical disease, Shiga toxin (Stx) is being appreciated as a useful tool in various aspects of cell physiology. These include defining signal transduction pathways (1–5), intracellular monitors of homeostatic processes (6–8), inducers of apoptosis (9 ...

Estimates of the risk of infection by the parasites that cause malaria govern decisions regarding vector control, chemoprophylaxis, therapeutic management, and clinical classifications of immunological susceptibility to infection. Gauging the risk of malaria represents a ...

Publication of the complete 1.83-Mb genome sequence of the bacterium Haemophilus influenzae strain Rd in 1995 (1) heralded a revolution in the study of microorganisms. The availability of a complete microbial genome sequence enormously facilitates computer-based and experimen ...

It has recently become possible to generate high-titer papillomavirus-based gene-transfer vectors. The vectors, also known as papillomavirus pseudoviruses (PsV), have been useful for studying papillomavirus assembly, entry, and neutralization, and may have future utility as ...

The major route of transmission of the human immunodeficiency virus type 1 (HIV-1) worldwide, like other agents of sexually transmitted disease, is via mucosal surfaces of the genital tract through sexual exposures (1–4). It has been hypothesized that immune responses at these sites may be im ...

Human papillomavirus (HPV) transcription is a complex process using multiple promoters, splices, and polyadenylation sites to create polycistronic transcripts capable of encoding the known and putative viral genes at the correct time and place throughout the differentiation ...

Despite the small genomes and number of genes of papillomaviruses, regulation of their transcription is very complex and governed by numerous transcription factors, cis-responsive elements, and epigenetic phenomena. This chapter describes the strategies of how one can approach a ...

The identification of papillomavirus DNA sequences in tissue samples using polymerase chain reaction (PCR) amplification, has led to the association of these infections to a multiplicity of clinical manifestations. The cloning and sequencing of PCR-amplified products has, to da ...

Improvements in methodologies to recapitulate and study particular biological functions of the papillomavirus life cycle have led to great advances in our knowledge of these viruses. Described in this chapter are techniques that allow low-copy and high-copy replication of full-le ...

The genomes of human and animal papillomaviruses amplify in keratinocytes undergoing terminal squamous differentiation. Two approaches have been developed to facilitate the investigation into the requirement for viral DNA replication and its regulation outside the conte ...

Human papillomaviruses (HPVs) are etiologic for the development of cervical cancer and its precursor lesions, cervical intraepithelial neoplasia (CIN). Nearly all cervical carcinomas (CaCx) harbor HPV DNA, but the presence of HPV alone is not indicative of the future development of ne ...

Papillomavirus late gene expression is highly dependent on host epithelial cell differentiation, such that capsid proteins are produced only in differentiating cells. Several papillomaviruses contain negative regulatory elements (NREs), that is, short regions of late tran ...