Recombinant adenoviruses are one of the most common vehicles for efficient in vitro and in vivo gene deliveries. Here, we investigate whether exogenous precursor terminal protein (pTP) expression in 293 cells improves the efficiency of adenovirus packaging and amplification. We used a piggyBac transposon-based vector and engineered a stable 293 line that expresses high level of Ad5 pTP, designated as 293pTP. Using the AdBMP6-GLuc that expresses green fluorescent protein (GFP), BMP6 and Gaussia luciferase, we found that the infectivity of AdBMP6-GLuc viral samples packaged in 293pTP cells was titrated up to 19.3 times higher than that packaged in parental 293 cells. AdBMP6-GLuc viral samples packaged in 293pTP cells exhibited significantly higher transduction efficiency in 143B and immortalized mouse embryonic fibroblast (iMEF) cells, as assessed by fluorescence-activated cell sorting analysis of GFP-positive cells, the luciferase activity assay and BMP6-induced osteogenic marker alkaline phosphatase activities in iMEFs. When adenovirus amplification efficiency was analyzed, we found that 293pTP cells infected with AdBMP6-GLuc yielded up to 12.6 times higher titer than that in parental 293 cells, especially at lower multiplicities of infection. These results strongly suggest that exogenous pTP expression may accelerate the packaging and amplification of recombinant adenoviruses. Thus, the engineered 293pTP cells should be a superior packaging line for efficient adenovirus production.

Severe acute respiratory syndrome (SARS) was caused by a novel virus now known as SARS coronavirus (SARS-CoV). The discovery of SARS-CoV-like viruses in masked palm civets (Paguma larvata) raises the possibility that civets play a role in SARS-CoV transmission. To test the susceptibility of civets to experimental infection by different SARS-CoV isolates, 10 civets were inoculated with two human isolates of SARS-CoV, BJ01(with a 29-nucleotide deletion) and GZ01 (without the 29-nucleotide deletion). All inoculated animals displayed clinical symptoms, such as fever, lethargy, and loss of aggressiveness, and the infection was confirmed by virus isolation, detection of viral genomic RNA, and serum-neutralizing antibodies. Our data show that civets were equally susceptible to SARS-CoV isolates GZ01 and BJ01.Severe acute respiratory syndrome (SARS) first appeared in Guangdong, China, in November 2002, and it subsequently spread to many parts of the world, making it the first major infectious disease outbreak of the 21st century (8,13,19). The etiological agent was a newly emerged and previously unrecognized coronavirus, now known as SARS coronavirus (SARSCoV) (2,3,(5)(6)(7)12), which is classified within the order Nidovirales, family Coronaviridae, genus Coronavirus (9,14,15). Epidemiological data obtained from the early stage of the SARS outbreak suggest an animal origin for SARS-CoV, although the reservoir host has yet to be identified (11,(20)(21)(22). The isolation of SARS-CoV-like viruses in masked palm civets and the relationship of their genomic sequences with those of viruses isolated from humans (1, 4) raise the possibility that civets play a role in SARS-CoV transmission to the human population. A striking difference between the vast majority of SARS-CoV genomes from humans and those from civets is the presence in the latter of an additional 29-nucleotide (nt) sequence 246 nt upstream of the start codon of the N gene. Only human SARS-CoV isolated from the earliest stage of the outbreak contains this same 29-nt additional sequence (1). In other words, most human SARS-CoV isolates had a 29-nt deletion in this region of the genome. Thus, while it is clear that SARS-CoV with and without the 29-nt deletion can replicate in humans, the influence of the 29-nt deletion on the capacity of the virus to replicate in civets has not been determined. Here we show that civets are equally susceptible to experimental infection with two different human SARS-CoV isolates, one containing and the other lacking the 29-nt sequence, and that all animals display clinical signs during the early stage of infection.SARS-CoV isolates GZ01 and BJ01 used in this study were originally isolated in Vero E6 cells at the Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Beijing, China, and were propagated in Vero E6 cells for two additional passages at our institute in Harbin to generate virus stocks with titers of 10 6 50% tissue culture infective doses (TCID 50 )/ml. BJ01 has the 29-nt deletion found in most hu...

One hundred and twenty-six blood samples were collected from healthy sheep and goats in Xinjiang, China, during July 2014. Seventy-three samples (57.93%) were bluetongue virus (BTV) serology-positive, and 39 samples (30.95%) were BTV NS1 gene-positive. BTV strain XJ1407 was isolated from the blood of BTV NS1 gene-positive animals and sequenced. Analysis of its genome sequence suggests that XJ1407 is a novel BTV serotype.