To make full use of research data, the bioscience community needs to adopt technologies and reward mechanisms that support interoperability and promote the growth of an open ‘data commoning’ culture. Here we describe the prerequisites for data commoning and present an established and growing ecosystem of solutions using the shared ‘Investigation-Study-Assay’ framework to support that vision.
Although the virus yield reduction assay is a powerful technique for evaluating the efficacy of antiviral compounds, it is not routinely utilized due to its labor-intensive nature. This procedure was modified, developed, thereby reducing greatly the time and effort required to perform yield reduction assays. Monolayer cultures of mammalian cells were grown in 96-well microtiter tissue culture plates and infected with virus. Test compounds were added and serially diluted directly with the plates. Following a cycle of virus replication, culture lysates were made and serially diluted in a separate set of uninfected cultures grown in microtiter plates. The cultures were incubated, plaques were enumerated in wells containing 5 to 20 plaques, and virus titers were calculated. To illustrate the use of the assay the known antiviral drugs acyclovir and ganciclovir were evaluated using this procedure. Ninety percent inhibitory concentrations for the respective drugs were 3 microM and 0.7 microM against herpes simplex virus type 1 and 60 microM and 1 microM against human cytomegalovirus.
The correlation of plasmid profiles with infectivity was investigated by using five clones of Borrelia burgdorferi sensu stricto strain B31 (ATCC 35210). Plasmid profiles were determined by pulsed-field and two-dimensional gel electrophoresis. The 50% infectious dose (ID 50) in hamsters was determined. The ID 50 of the clone that possessed a full complement of eight linear and three circular plasmids was 10 3 cells. The loss of the 27.5-and 40-kb linear plasmids did not decrease the infectivity of these cells. Rather, the loss of the 27.5-kb linear plasmid was associated with a more disseminated infection. A moderate decrease of the ID 50 from 10 3 to 10 5 cells correlated with the loss of the 9.0-kb circular plasmid and the 27.5-kb linear plasmid. A major loss of infectivity (ID 50 > 10 8 cells) occurred with cells that lost the 24.7-and 27.5-kb linear plasmids and the 9.0-kb circular plasmid. A 3.0-kb HindIII fragment of the 24.7-kb linear plasmid was used as a probe to determine the presence of the homologous sequences in the three genospecies of Lyme disease spirochetes. An analysis of 21 infectious strains of B. burgdorferi sensu stricto, B. garinii, and B. afzelii revealed a consistent association of infectivity with strains possessing a linear plasmid (size range, 24 to 36 kb) that hybridized with the HindIII fragment. Western immunoblotting with hamster antisera against infectious B31 clone C-3 revealed two proteins with molecular masses of 28 and 43 kDa that were absent in the noninfectious B31 clone C-1. Additionally, a 14-kDa protein was absent in C-1 but present in infectious clone C-9 as shown by twodimensional polyacrylamide gel electrophoresis. Lyme disease is a multisystem disorder caused by three closely related Borrelia genospecies: Borrelia burgdorferi sensu stricto, B. afzelii, and B. garinii (1, 10, 12, 26, 37). B. burgdorferi sensu stricto will be referred to as B. burgdorferi hereafter in this work. The Borrelia genome is composed of one linear chromosome of about 950 kb with multiple linear and circular plasmids (3-5, 18, 24, 43, 45). Considerable diversity in plasmid profile among Lyme disease spirochetes obtained from different biological sources and geographical locations has been observed (3, 23, 45, 46). The function of plasmids in the virulence of B. burgdorferi is unknown. Genes specifying the outer surface lipoproteins (OspA,-B,-C,-D,-E, and-F) are located on plasmids. The genes ospAB, ospEF, and ospD are present on 49-, 45-, and 38-kb linear plasmids, respectively (7, 28, 32), while ospC is located on a 26-to 27-kb circular plasmid (19, 29, 38). Recently, the gene coding for exported plasmid protein A (EppA) was cloned from a 9-kb circular plasmid (15). The functions of these proteins in the virulence of B. burgdorferi remain to be elucidated. Serial in vitro cultivation of B. burgdorferi results in plasmid profile changes which are accompanied by the loss of infectivity in experimental animals (25, 31, 42). Previous reports (25, 31, 42) suggested a potential role for plasmids in ...
A mutant of virulent Borrelia burgdorferi 297 was apparently selected for by long-term storage at 5°C. This mutant was found to lack the plasmid which encodes outer surface protein A (OspA) and OspB. In addition to the loss of the OspA and OspB proteins, the mutant lacked two lipoproteins, of 20 and 7.5 kDa, that were observed in the wild type. Since the mutant was not recovered from the tissues or blood of hamsters injected with the mutant, the mutant was determined to be noninfectious. Hamsters vaccinated with noninfectious mutant 297 were protected completely from challenge with virulent wild-type 297 spirochetes. Prechallenge sera from hamsters vaccinated with mutant 297 lacked antibodies to OspA and OspB, while those from hamsters vaccinated with virulent wild-type 297 or avirulent 297 exhibited antibodies to these proteins. Hamsters vaccinated with virulent wild-type 297 or mutant 297 elicited antibodies to OspC and a 39-kDa protein (P39), whereas hamsters vaccinated with avirulent 297 lacked these antibodies. These results suggest that OspC and/or P39 are important for the development of a protective immune response. Study of this mutant may elucidate factors important to the development of a Lyme disease vaccine.
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