A novel isophorone-derived fluorescent probe for detecting sulfite and the application in monitoring the state of hybridoma cells.

In this work, a novel isophorone-derived fluorescent probe, ISOP-SFT, was developed for the detection of sulfite, and, for the first time, it was applied into monitoring the state of hybridoma cells. ISOP-SFT could exhibit a red-emission response to sulfite with the excitation at 455 nm. It also indicated practical advantages such as wide pH tolerance within 6.0-9.0 and high storage steadiness within at least one week. The linear range was relatively long (0-20 Eq) and reliable (Pearson's correlation coefficient: 0.9989), while Limit of Detection was determined as 0.0095 Eq (95 nM). For the selectivity, ISOP-SFT could distinguish sulfite from other analytes, and the response of ISOP-SFT towards sulfite was not seriously interfered in co-existence system. With low cytotoxicity, ISOP-SFT achieved monitoring both the exogenous and endogenous sulfite in living MCF-7 cells. As a novel attempt, ISOP-SFT was applied into monitoring the state of hybridoma cells, and associated with the quality control of producing antibodies. The result preliminarily inferred the positive correlation between the production efficiency of antibodies in hybridoma cells and the intracellular sulfite level, including the conditions of serum starvation, oxidative stress, severe hypoxia and endogenous induction. We hope that the information in this work could lead to new applications of fluorescent probes in biological industry in future.

Pathogenicity and horizontal transmission studies of caprine parainfluenza virus type 3 JS2013 strain in goats.

Parainfluenza virus type 3 (PIV3) is one of the most important viral respiratory pathogens for humans and for many animals, but goat infection has been rarely reported. In 2014, one novel PIV3 strain was first isolated from goats suffered respiratory diseases in Jiangsu and Anhui provinces of eastern China and named as caprine PIV3 (CPIV3) JS2013. In order to systematically evaluate the pathogenicity and horizontal transmission ability of this new virus, experimental infection of goats with the CPIV3 strain was done. The virus-inoculated goats (challenge control (CC) group) displayed coughing and nasal discharges from 3days post infection (dpi) and lasted for about 2 weeks. Two goats in group CC showed fever between 7 and 12dpi. As detected by a TaqMan real time quantitative RT-PCR (qRT-PCR), viremia was detected during 3-11dpi, peaked at 6dpi; and virus shedding from nasal discharge and faeces were confirmed during 3-21dpi and 4-21dpi, respectively. Virus-specific HI antibodies and neutralizing antibodies (NAs) became positive since 7dpi and 14dpi; peaked at 14dpi and 28dpi, respectively; and lasted at least 70days. Pathological lesions were mainly found on the lungs and tracheas. In addition, viruses were also detected in part of the tracheal secretion and lung samples, and the viral load in tracheal secretion was higher than that in lungs. Goats in horizontal infected group (hCC, kept in different cages in the same house with CC group) showed to be horizontally infected, with slightly milder clinical signs and pathological changes; and slightly shorter period of viremia and virus shedding. This was the first report of the detailed pathogenicity characterization of the novel CPIV3 and demonstrated its horizontal transmission ability. The results would be helpful for further studies on the preventive and control strategies for CPIV3 infections.

Analysis on the complete genome of a novel caprine parainfluenza virus 3.

Parainfluenza virus type 3 (PIV3) is one of the most important viral respiratory pathogens for humans and for many animals. One unique caprine PIV3 (CPIV3) strain named JS2013 was isolated in Chinese goat flocks with respiratory diseases in 2013. Now, the complete genome sequence of the strain JS2013 had been determined. A total of 15 overlapping DNA clones, covering the entire genome of the virus, were obtained by primer walking RT-PCR. The sequences of the 3' and 5' termini of the viral genome were amplified by 3' and 5' RACE. The viral genome was 15,618 nucleotides (nt) in length, which was consisted of six genes in the order 5'-leader-N-P/C/V-M-F-HN-L-tailer-3'. The junction sequences between two genes were highly conserved gene start and stop signal sequences, and trinucleotide intergenic regions (IGR) similar to those of other reported PIV3 strains. Phylogenetic analysis based on the complete genomes of JS2013 with other strains of genus Respirovirus demonstrated that the JS2013 obviously differed from HPIV1, Sendai virus, HPIV3 and other reported BPIV3 genotypes. Further analysis of HN genes of JS2013 along with two more CPIV3 strains isolated later indicated that CPIV3 strains formed a separate cluster. The results presented here suggested that CPIV3 is a new member of the genus Respirovirus.

Chinese border disease virus strain JSLS12-01 infects piglets and down-regulates the antibody responses of classical swine fever virus C strain vaccination.

During 2012 and 2013, several border disease virus (BDV) strains were identified from Chinese goat and sheep herds. At the same time, pigs from the same areas were found to be seropositive to BDV by ELISA, without showing clinical signs (unpublished data). To examine the susceptibility of pigs to the Chinese BDV strains, BDV isolate JSLS12-01, isolated from naturally infected sheep, was used to infect pigs. Antibody responses, viremia, clinical signs and pathological changes of the infected animals were examined. It confirmed that the current BDV strain could infect the domestic pigs, the animals showed viremia during 4 to 14 days post infection (dpi) and sero-conversion from 14dpi; no clinical and pathological changes were observed. In addition, CSFV maternal antibody did not influence BDV infection. Subsequently, pigs were infected with the BDV isolate and vaccinated with Hog cholera lapinized virus (HCLV) 21 days later to determine the effect of BDV infection on antibody induction of CSFV vaccination. The specific CSFV antibody and neutralizing antibody titers of the BDV infected group remained negative after the primary vaccination. Even after the boost vaccination, they were still significantly lower than those of the uninfected groups (p<0.05). These results indicated that BDV infection could down-regulate the antibody responses of CSFV C-strain vaccination. It should be paid attention that BDV prevalence in pig herds and in live vaccines might hamper the vaccination of CSF.

A novel parainfluenza virus type 3 (PIV3) identified from goat herds with respiratory diseases in eastern China.

Parainfluenza virus type 3 (PIV3) is one of the most important viral respiratory pathogens for humans and for many animals, but goat infection has been rarely reported. Starting in Aug 2013, goats in the Jiangsu and Anhui provinces of eastern China suffered severe respiratory diseases. In order to identify the causative agent, numerous related pathogens were tested with RT-PCR or PCR. A unique PIV3 strain was detected in most of the clinical nasal swabs or serum samples. The virus was isolated on MDBK cells and characterized by RT-PCR, nucleotide sequence analysis and hemagglutination test. The entire M and F gene coding regions, HN, 5'-UTR-N and L gene fragments were amplified using pairs of degenerate primers. Nucleotide, amino acid sequence alignments and phylogenetic analyses based on these genes indicated that the goat-derived PIV3 strain was distinct from previously reported BPIV3 genotypes and HPIV3 strains. The novel isolate, named JS2013, might be a potentially new member of the respirovirus genus. Goats were experimentally infected with JS2013 culture. The virus-inoculated goats displayed coughing and nasal discharges that were related to respiratory diseases. Viremia and virus shedding were detected during 4-10 days post-inoculation (dpi). Virus-specific HI antibodies became positive from 14 dpi. This is the first report of the detection of PIV3 from Chinese goat herds and genetic and pathogenetic characterization of the novel goat-derived PIV3.