Developments in biologicals最新文献

Many factors play into the complexity of viral pathogenesis. Understanding viral pathogenesis is key to developing vaccines and treatments for viral diseases. One emerging area of research is proteomics, which is the study of the protein complement and functions of the genome. Many different proteomic approaches have been utilized by researchers worldwide to further elucidate viral pathogenesis. For example, a high throughput MALDI-MS approach was recently employed to study the antigenicity of the influenza virus. Another study utilized MALDI-TOF MS and liquid chromatography MS/MS of proteins present in lipid droplets of hepatoma cell lines to identify proteins involved in the pathogenesis of hepatitis C virus that contribute to its carcinogenic properties. In conjugation with MS, yeast two-hybrid systems have also been shown to be useful in identifying potential host receptors of various viruses as well as revealing the interaction of viral proteins with other host proteins and viral proteins. In this review, the focus is on various proteomic approaches to dissecting the mechanisms of viral pathogenesis.

The first International Symposium on Animal Genomics for Animal Health (AGAH) provided an excellent venue for scientists working in the field of genomics to interact with animal health experts. This paper provides an introduction to genome-enabled tools and highlights some of the research projects in the AGAH proceedings. A brief review of animal genomes, the next generation of genetic markers, and the versatility of genome-enabled technologies and their many applications are discussed.

This analysis of the present rabies situation in Western Europe is based on completed questionnaires from 16 countries. The questionnaire focuses on the years 2005 and 2006. Additional information was obtained from the Rabies Bulletin Europe, and from the OIE's publication on "Historical Perspective of Rabies in Europe and the Mediterranean Basin". Rabies in domestic animals and wild carnivores has become very rare in Western Europe. Only Germany reported a low number of rabid foxes for 2005. Bat rabies was observed in four countries. One imported human case was seen in the UK, while Germany reported four cases in transplant recipients. Wildlife vaccination campaigns were conducted by Austria, Germany and France. Reporting of human post-exposure prophylaxis is inconsistent due the lack of information. Similarly, data on domestic animal rabies prophylaxis seem to be difficult to collect.

This study aimed at analyzing a ten-day observation period of rabies suspected dogs and cats according to six criteria. Dogs and cats suspected of being rabid were brought for observation when they had either bitten a person or another animal or when abnormal behaviour or unusual illness was observed. Between 1985 and 2005, retrospective and prospective data from 1,222 dogs and 303 cats was collected during the ten-day observation period. If an animal had died, brain examination using fluorescent antibody testing was routinely performed. If an animal had survived for > or =10 days, it was released to its owner or transferred to the municipal dog shelter. A total of 644 dogs and 58 cats found rabid died within 10 days of observation. In addition, for 208 dogs confirmed rabid with laboratory tests between 1997 and 2005, six criteria were analysed from the day of submission. This experience with the implemented 10-day observation period confirms the WHO recommendation on identifying suspected rabid dogs or cats under veterinary supervision following a human exposure.

Experimental studies have been undertaken to assess the susceptibility of silver foxes to bat variants of rabies virus, namely European Bat Lyssaviruses (EBLVs). Both EBLV-1 and EBLV-2 have been isolated in European bats since 1954, in Eptesicus serotinus and Myotis species, respectively. Since 2000, the number of reported cases has increased largely due to the improvement of the surveillance of bat rabies virus throughout Europe. Although over >800 EBLVs cases have been reported in bats in Europe, EBLV-1 and -2 viruses are rarely reported to infect humans and terrestrial animals. The study presented here shows that the sensitivity of silver foxes is low when infected with EBLVs via the intramuscular route; in contrast all animals infected via intracranial inoculation succumbed to the experimental challenge. The mortality rate was 100% for both EBLV-1 (approximately 4.5 log) and EBLV-2 (approximately 3.0 log). This data suggests that the susceptibility of foxes to EBLV-1 and EBLV-2 is low and that the transmission (spillover) and adaptation of EBLVs from a bat to a fox may be theoretically possible but unlikely.

The Finnish-Russian collaboration on rabies control began in 2000. This data summarizes the results of the scientific part of the programme, including rabies monitoring in Russia and the molecular epidemiological studies with field viruses.

The possibility of genetically engineering poultry to make them resistant to avian influenza is attracting attention and has now become a real possibility with improved methods for genetic modification and the emergence of RNAi as an antiviral strategy. In order to test this possibility, we have generated transgenic mice that express RNAi molecules targeting a conserved region of the influenza A NP gene and are testing these mice for resistance to influenza infection. Transgenes were initially developed that express short hairpin RNAs (shRNAs) targeting multiple influenza A viral genes. The shRNAs were tested for inhibition of H1N1 PR8 virus in vitro. Two potent shRNAs that target the NP and PA genes were chosen for lentiviral mediated generation of transgenic mice. Transgenic founders for the NP shRNA construct and also a negative control shRNAtargeting EGFP were generated. The constitutive expression of the shRNA molecules in a range of tissue types including lung, was confirmed and so far stable transmission of the RNAi transgenes from the F0 to F3 generation has been observed. Resistance to influenza infection in these transgenic mice is now being confirmed.

Bovine viral diarrhoea viruses (BVDV) are significant pathogens of cattle worldwide. These viruses exist in both non-cytopathic and cytopathic biotypes. Non-cytopathic BVDV can establish persistent lifelong infections in cattle and are a frequent contaminant of biological reagents such as cell cultures and foetal bovine serum. We identified commercially available bovine aortic endothelial cells (BAECs) contaminated with BVDV. In this study, to determine if BVDV alters endothelial gene transcription patterns, serial analysis of gene expression (SAGE) was used to compare gene expression profiles from uninfected and BVDV contaminated BAEC. SAGE is an open ended, quantitative method for characterizing global patterns of transcription. Comparison of expression profiles of BVDV-contaminated and noninfected cells revealed significant increases in the transcription of many genes including P-selectin, tryptophan tRNA synthetase and prostaglandin D2 synthase. These changes were validated by real-time PCR. Additionally, real-time PCR demonstrated that the response to LPS and dsRNA by contaminated cells, as well as cells acutely infected with noncytopathic BVDV, is altered. The altered response may be through the high level of expression of A20 and inhibition of activation of NF-kappaB. BAECs are commonly used as a model to study endothelial cell function in many different systems. As shown here, transcriptional and probable protein changes resulting from BVDV infection significantly alter cellular responses and may have a profound impact on experimental outcome. Transcriptomic analysis provided the initial clues leading to the characterization of this altered function.

The very early in vivo response to immune stimuli was studied using tetanus toxoid as a model antigen known to induce Th1 and Th2 responses. Eighteen weaning piglets were vaccinated subcutaneously with tetanus toxoid. Leukocyte RNAs were isolated from samplings before and 2, 4, 8, and 24 hours after vaccination. After competitive hybridization of a 13297 porcine 70-mer oligo microarray (Qiagen-Operon NRSP8), subsequent image analysis and normalization, the data was analysed using analyses of variance (ANOVA) to identify genes regulated due to vaccination (ANOVA, p < or = 0.05; corresponding to false discovery q < or = 0.12). Of 8240 probes representing genes expressed in leukocytes, 1289 genes showed differential expression. Results were exemplarily confirmed by real-time PCR. Holistic expression data was clustered to six prominent groups of genes with similar changes in expression patterns using a k-means algorithm. To get more insight into functional and structural components and impact of the genes represented in each cluster, the EASE score was used to identify Gene Ontology functional categories. The results showed that in vivo significant changes of expression profiles of peripheral blood mononuclear cells (PBMCs) occurred very early after immune stimuli. These alterations concerned genes of pathways related to immune response as well as other metabolic and regulatory pathways including ATP/energy metabolism, transcription, structural molecule activity, biosynthesis, and metabolism. The analysis reveals new functional candidate genes for traits related to immune responsiveness and also provides new insight into the interaction of immune response, and metabolic and endocrine status. This will facilitate a better understanding of the relationship between immune and performance traits.

Two novel methods for genome wide selection (GWS) were examined for predicting the genetic merit of animals using SNP information alone. A panel of 1,546 dairy bulls with reliable EBVs was genotyped for 15,380 SNPs that spanned the whole bovine genome. Two complexity reduction methods were used, partial least squares (PLS) and regression using a genetic algorithm (GAR), to find optimal solutions of EBVs against SNP information. Extensive internal cross-validation was used tofind the best predictive models followed by external validation (without direct use of the pedigree or SNP location). Both PLS and GAR provided both accurate fit to the training data set for somatic cell count (SCC) (max r = 0.83) and fertility (max r = 0.88) and showed an accuracy of prediction of r = 0.47 for SCC, and r = 0.72 for fertility. This is the first empirical demonstration that genome wide selection can account for a very high proportion of additive genetic variation in fitness traits whilst exploiting only a small percentage of available SNP information, without use of pedigree or QTL mapping. PLS was computationally more efficient than GAR.