Targeting of tumor associated antigens in renal cell carcinoma using proteome-based analysis and their clinical significance

The suitability of proteome-based strategies for the targeting of tumor-associated markers along with further analysis regarding their clinical significance were investigated in human renal cell carcinoma (RCC). The immunogenic protein expression profile of normal kidney and RCC cell lines was studied by proteome analysis combined with immunoblotting using sera from healthy donors and RCC patients, also termed PROTEOMEX. Employing this approach, a series of proteins reactive with either RCC patient sera and/or reactive with control sera were identified by microanalysis of tryptic peptides. Some of these candidate antigens represent members of the cytoskeletal family, such as cytokeratins, in particular cytokeratin 8, cytoskeletal tropomyosin, F-actin capping protein, gamma-actin, stathmin, tubulin-alpha, tubulin-beta and vimentin. The expression pattern and clinical significance of three of these antigens, namely cytokeratin 8, stathmin and vimentin, were further analyzed in a large series of surgically removed RCC lesions of distinct subtypes. A heterogeneous expression pattern of cytokeratin 8, stathmin and vimentin was demonstrated in the different RCC subtypes. All epithelial cells of the autologous normal kidney showed a strong cytokeratin 8 staining pattern, whereas they totally lack vimentin expression. Stathmin was expressed in 10% of tubule cells. In conclusion, PROTEOMEX could be employed for the identification of tumor-associated antigens of the cytoskeleton which are differentially expressed in RCC of distinct subtypes as well as in normal renal epithelium.     

Osteoprotegerin (OPG) is localized to the Weibel-Palade bodies of human vascular endothelial cells and is physically associated with von Willebrand factor

Recent studies demonstrate roles for osteoprotegerin (OPG) in both skeletal and extra-skeletal tissues. Although its role in preventing osteoclast (OC) formation and activity is well documented, emerging evidence suggests a role of OPG in endothelial cell survival and the prevention of arterial calcification. In this communication, we show that vascular endothelial cells in situ, and human umbilical vein endothelial cells (HUVEC) in vitro, express abundant OPG. In HUVEC, OPG co-localizes with P-selectin and von Willebrand factor (vWF), within the Weibel-Palade bodies (WPB). Treatment of HUVEC with the pro-inflammatory cytokines, tumor necrosis factor (TNF)-alpha and IL-1beta, resulted in mobilization from the WPBs and subsequent secretion of OPG protein into the culture supernatant. Furthermore, TNF-alpha treatment of HUVEC resulted in a sustained increase in OPG mRNA levels and protein secretion over the 24-h treatment period. Reciprocal immunoprecipitation experiments revealed that while not associated with P-Selectin, OPG is physically complexed with vWF both within the WPB and following secretion from endothelial cells. Interestingly, this association was also identified in human peripheral blood plasma. In addition to its interaction with vWF, we show that OPG also binds with high avidity to the vWF reductase, thrombospondin (TSP-1), raising the intriguing possibility that OPG may provide a link between TSP-1 and vWF. In summary, the intracellular localization of OPG in HUVEC, in association with vWF, together with its rapid and sustained secretory response to inflammatory stimuli, strongly support a modulatory role in vascular injury, inflammation and hemostasis.     

Harnessing Case Isolation and Ring Vaccination to Control Ebola

As a devastating Ebola outbreak in West Africa continues, non-pharmaceutical control measures including contact tracing, quarantine, and case isolation are being implemented. In addition, public health agencies are scaling up efforts to test and deploy candidate vaccines. Given the experimental nature and limited initial supplies of vaccines, a mass vaccination campaign might not be feasible. However, ring vaccination of likely case contacts could provide an effective alternative in distributing the vaccine. To evaluate ring vaccination as a strategy for eliminating Ebola, we developed a pair approximation model of Ebola transmission, parameterized by confirmed incidence data from June 2014 to January 2015 in Liberia and Sierra Leone. Our results suggest that if a combined intervention of case isolation and ring vaccination had been initiated in the early fall of 2014, up to an additional 126 cases in Liberia and 560 cases in Sierra Leone could have been averted beyond case isolation alone. The marginal benefit of ring vaccination is predicted to be greatest in settings where there are more contacts per individual, greater clustering among individuals, when contact tracing has low efficacy or vaccination confers post-exposure protection. In such settings, ring vaccination can avert up to an additional 8% of Ebola cases. Accordingly, ring vaccination is predicted to offer a moderately beneficial supplement to ongoing non-pharmaceutical Ebola control efforts.     

Mitochondrial DNA polymorphisms in subterranean mole-rats of the Spalax ehrenbergi superspecies in Israel, and its peripheral isolates

Patterns of mitochondrial DNA (mtDNA) variation were examined in 133 mole-rats constituting all four chromosomal species (2n = 52, 2n = 54, 2n = 58, and 2n = 60) of the Spalax ehrenbergi superspecies in Israel, as well as the peripheral isolates of 2n = 60. In the main range of the complex, a total of 28 mtDNA haplotypes were found in 64 mole-rats, with most haplotypes being unique to either a single chromosomal species or population. mtDNA divergence increased from low to high diploid number in a north-to-south direction in Israel. Overall levels of mtDNA diversity were unexpectedly the highest in the 2n = 60, the youngest species of the complex. The mtDNA haplotypes can be separated into two major groups, 2n = 52-54 and 2n = 58-60, and a phylogenetic analysis for each group revealed evidence of a few haplotypes not sorted by diploid number. The overall patterns of mtDNA divergence seen within and among the four chromosomal species are consistent with the parapatric mode of speciation as suggested from previous studies of allozyme and DNA hybridization. In a separate data set the patterns of mtDNA variation were examined across the main geographic range and across peripheral semi-isolates and isolates of the 2n = 60 chromosomal species. Fifteen haplotypes were found in 69 mole-rats. High levels of mtDNA diversity characterized the main range, semi-isolated, and even some desert isolated populations. The peripheral isolates contain much mtDNA diversity, including novel haplotypes.      

Metabolism and translocation of fixed nitrogen in the nodulated legume

Summary Nitrogen (N₂) fixed by Rhizobium bacteroids in the legume nodule is excreted as ammonia to the surrounding host cell where it is efficiently assimilated into the amide group of glutamine. Generally glutamine is a minor exported solute of nitrogen, being further metabolised to asparagine in temperate species and to the ureides, allantoin and allantoic acid in tropical species. These solutes serve as the principal translocated forms of nitrogen in xylem. Compartmentalisation of the pathways of nitrogen metabolism and the role of ammonia in regulation of their activity is examined in nodules of both asparagine-forming (Lupinus albus L.) and ureide-forming (Vigna unguiculata L. Walp) symbioses.     

Some Bacteriophages Active Against Rhizobium trifolii Strain W19

Fourteen soil bacteriophages active against Rhizobium trifolii W19 have been studied which fall into four structural groups. Group 1 phages have contractile tails. Some particles show double base plates to which at least three spikes are attached, and fibers are attached to the base plates. Group 2 phages also have contractile tails. At least five spikes are attached to the base plate, and there are spherical bodies adjacent to the tail, at the ends of fibers attached to the tail base. Group 3 phages have contractile tails, but are larger than phages of groups 1 and 2. The end of the tail has a complex structure. Group 4 phages have long, noncontractile tails.     

VACCINATION AND REDUCED COHORT DURATION CAN DRIVE VIRULENCE EVOLUTION: MAREK’S DISEASE VIRUS AND INDUSTRIALIZED AGRICULTURE

Marek’s disease virus (MDV), a commercially important disease of poultry, has become substantially more virulent over the last 60 years. This evolution was presumably a consequence of changes in virus ecology associated with the intensification of the poultry industry. Here, we assess whether vaccination or reduced host life span could have generated natural selection, which favored more virulent strains. Using previously published experimental data, we estimated viral fitness under a range of cohort durations and vaccine treatments on broiler farms. We found that viral fitness maximized at intermediate virulence, as a result of a trade‐off between virulence and transmission previously reported. Our results suggest that vaccination, acting on this trade‐off, could have led to the evolution of increased virulence. By keeping the host alive, vaccination prolongs infectious periods of virulent strains. Improvements in host genetics and nutrition, which reduced broiler life spans below 50 days, could have also increased the virulence of the circulating MDV strains because shortened cohort duration reduces the impact of host death on viral fitness. These results illustrate the dramatic impact anthropogenic change can potentially have on pathogen virulence.     

Expression in Streptomyces lividans and Saccharopolyspora erythraea of gene fusions between the eryA promoter region and aph as reporter gene

Fusions between regions upstream of eryAI and the aph reporter gene were studied. In high copy number plasmids, DNA extending 262 bp upstream of the EryAI translation start sufficed for full kanamycin/neomycin phosphotransferase (APH) expression in Streptomyces lividans. Low copy number constructs gave similar APH activities in Saccharopolyspora erythraea and S. lividans, in accord with the idea that there is no pathway-specific regulatory gene in this system. © Rapid Science Ltd. 1998