Commercial E2 subunit vaccine provides full protection to pigs against lethal challenge with 4 strains of classical swine fever virus genotype 2.

Classical swine fever (CSF) still threatens the swine industry in China, with genotype 2 isolates of CSFV dominating the epizootics. In 2018 the first E2 subunit marker vaccine against CSFV (Tian Wen Jing, TWJ-E2®), containing a baculovirus-expressed E2 glycoprotein of a genotype 1.1 vaccine strain, was officially licensed in China and commercialized. To evaluate the cross-protective efficacy of TWJ-E2 against different virulent genotype 2 Chinese field isolates (2.1b, 2.1c, 2.1 h, and 2.2), 4-week-old pigs were immunized with the TWJ-E2 vaccine according to the manufacturer's instructions and then challenged with genotype 2 strains. A group vaccinated with the conventional C-strain vaccine was included for comparison. TWJ-E2 vaccinated pigs developed higher levels of E2 and neutralizing antibodies than those receiving the commercial C-strain vaccine. All TWJ-E2 and C-strain vaccinated pigs survived challenge without development of fever, clinical signs or pathological lesions. In contrast, all unvaccinated control pigs displayed severe CSF disease with 40-100% mortalities by 24 days post challenge. None of the TWJ-E2 and C-strain vaccinated pigs developed viremia, viral shedding from tonsils, Erns protein in the sera, or viral RNA loads in different tissues after challenge, all of which were detected in the challenged unvaccinated controls. We conclude that vaccination of young pigs with TWJ-E2 provides complete immune protection against genotypically heterologous CSFVs and prevents viral shedding after challenge, with an efficacy at least comparable to that elicited by the conventional C-strain vaccine.

Virulence evaluation of classical swine fever virus subgenotype 2.1 and 2.2 isolates circulating in China.

Classical swine fever (CSF) remains an important pig disease in China, where it usually presents with mild or atypical clinical manifestations, with large scale outbreaks rarely seen. This has led to speculation about the possible circulation of viral strains of low virulence. To investigate this possibility, five field isolates within the predominant genotype 2 (2.1b, 2.1c, 2.1 h and 2.2) were evaluated and compared by experimental infection of naturally farrowed but colostrum-deprived piglets. All infected piglets displayed clinical signs, including persistent high fever, depression, anorexia, dyspnea, conjunctivitis, constipation, and hesitant gait. Typical pathological lesions, including pulmonary edema, hemorrhagic or cellulosic exudation, and swelling and hemorrhage of lymph nodes, were observed. Viremia and Erns protein expression in the blood of all infected animals were detectable from 3 to 5 days post infection (DPI), their presence correlating with the onset of fever, clinical signs and leukopenia. E2 antibody did not develop in any of the field CSFV-infected piglets during the disease course, while Erns antibody was detectable in 4-56% of infected animals at various time points. Mortalities ranged from 20 to 80% within 21 DPI, progressing to 100% by 43 DPI. Based on clinical scores and fatalities within 21 DPI, 2 of the 5 field isolates were classified as of moderate virulence and 3 of high virulence; i.e., no field isolates of low virulence were identified. The study has provided data supporting the use of these isolates as challenge viruses to evaluate the efficacy of current CSF vaccines.

[Characterization of the changes in protease of Deinococcus radiodurans following irradiation].

The activity of protease from Deinococcus radiodurans R1 (DRR1) recovered from UV light and gamma-ray irradiation were characterized by SDS-PAGE zymography or FITC-labeled casein as substrate. It was demonstrated that proteases with large molecular weight were abundantly and constitutively expressed in DRR1, which consistent with the hypothesis that proteases were among the PHX (predicted highly expressed) proteins in DRR1. A broad range of gelatinolytic protease with molecular mass more than 140 kD and caseinolytic protease with molecular mass more than 120 kD were present in DRR1 cell. The prominent gelatinolytic protease of 174 kD was also active when denatured by SDS and displayed different operation dynamics during the repair process post UV-irradiation and gamma-irradiation, the protease showed its highest activity during gamma-irradiation and in the late recovery stage post-irradiation. Some proteases were demonstrated to be induced specifically by irradiation which suggests that these proteases may regulate breakdown of proteins responsible in sequential pathway, and an elaborate and fine tuning protease system may exist in D. radiodurans during the repair process post irradiation. The expression of protease was also influenced by the nutrition of the culture. A rod-shaped and radiation resistant bacterium RR533.2 isolated from soil in Beijing, China was revealed to display similar zymography pattern using gelatin or casein as substrate.

Mitosin/CENP-F as a negative regulator of activating transcription factor-4.

Mitosin/CENP-F is a human nuclear matrix protein with multiple leucine zipper motifs. Its accumulation in S-G2 phases and transient kinetochore localization in mitosis suggest a multifunctional protein for cell proliferation. Moreover, its murine and avian orthologs are implicated in myocyte differentiation. Here we report its interaction with activating transcription factor-4 (ATF4), a ubiquitous basic leucine zipper transcription factor important for proliferation, differentiation, and stress response. The C-terminal portion of mitosin between residues 2488 and 3113 bound to ATF4 through two distinct domains, one of which was a leucine zipper motif. Mitosin mutants containing these domains were able to either supershift or disrupt the ATF4-DNA complex. On the other hand, ATF4, but not ATF1-3 or ATF6, interacted with mitosin through a region containing the basic leucine zipper motif. Moreover, overexpression of full-length mitosin repressed the transactivation activity of ATF4 in dual luciferase-based reporter assays, while knocking down mitosin expression manifested the opposite effects. These findings suggest mitosin to be a negative regulator of ATF4 in interphase through direct interaction.

Genotype and allele frequency of the variable number tandem repeat polymorphism in the VNTR6-1st of the of human telomerase reverse transcriptase (hTERT) gene in Chinese population.

The variable number of tandem repeat (VNTR) polymorphism in the intron 6 of the human telomerase reverse transcriptase(hTERT) was investigated. Seven alleles of 18, 20, 21, 22, 23, 26 and 35 repeats of the 36 bp VNTR6-1st and 14 genotypes were identified among 210 unrelated healthy Chinese individuals (Han people) living in Beijing. The 20, 22 and 35 repeats were the most frequent alleles which accounted for 94.76% of the total alleles observed. The allele frequency of the Chinese population showed no difference with that of the Korea population living in Pusan except for allele of 35 repeats. But the 5' flanking region of VNTR6-1st polymorphic sequence of the Chinese population included a 53-bp insert compared with that of korea population except for some alleles of 22 repeats.

[Isolation and characterization of a novel radiation-resistant rod-shaped bacterium].

A novel radiation-resistant bacterium was isolated from soil of lake bank in Beijing. The bacterium produced orange-pigmented colonies and formed rod-shaped cells that stained gram negative alike the Deinobacter grandis previously described by Japan's scientist. It was found with electron microscopy that the isolate is of 0.6 microm - 1.6 microm size and has a 30-40 nm thickness of cell wall, being slightly larger and thicker than the Deinobacter grandis. There was a difference in the concentration and molecule weight of catalase between the isolate and the Deincoccus radiodurans R1. The deoxyribonucleic acid guanine plus cytosine (G + C) base ratio was 70.7 mol%. 16S RNA gene sequencing also showed that this rod-shaped bacterium possessed a high homology with the Deinobacter grandis, suggesting that it might be classified into the genus Deinobacter and constitute a new species in this genus.

[A short tandem repeat polymorphism in the inducible nitric oxide synthase gene in Chinese population].

Polymorphism of the (CCTTT)n repeat, a short tandem repeats (STR) located in promoter region of the inducible nitric oxide synthase (iNOS) gene, was analyzed in a total of 316 Chinese healthy subjects. Twelve alleles and forty-nine genotypes were identified. Three alleles that had not been reported previously, namely 17-repeats, 18-repeats and 19-repeats, were found in Chinese population. Mendelian inheritance of the allele in a family composed of three generations was determined. Some of the observed allele frequency of this STR locus in Chinese differed significantly from that of Caucasians in England.