The oral cavity is an entrance for respiratory viruses, such as influenza. Recently, saliva has been shown to exert both antimicrobial and antiviral activities. Thus, saliva may be a biological ...factor that contributes to the prevention of influenza infection. However, the actual salivary anti-influenza A virus (IAV) activity in individuals and its determinant factors are unknown. By assessing individual variations in salivary anti-IAV activity in 92 people using an established new high-throughput system in this study, we found that the anti-IAV activity varied widely between individuals and showed a significant positive correlation with protein-bound sialic acid (BSA) level (ρ = 0.473; p < 0.001). Furthermore, the anti-IAV activity of saliva with enzymatically reduced BSA content was significantly lower. These results indicate that BSA is a direct regulator of salivary anti-IAV activity and is a determinant of individual differences. Additionally, after comparing the anti-IAV activity across the groups by age, anti-IAV activity in young people (aged 5-19 years) were lower than in adults aged 20-59 years and elderly people aged 60-79 years. Our study suggests that BSA levels in saliva may be important in preventing influenza infection.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
In this study, we developed a green light-regulated T7 RNA polymerase expression system (T7 RNAP system), to provide a novel and versatile high-expression system for cyanobacteria without using any ...chemical inducer, realizing high expression levels comparable with previously reported for recombinant gene expression in cyanobacteria. The T7 RNAP system was constructed and introduced into
Synechocystis
sp. PCC6803. T7 RNAP was inserted downstream of the
cpcG2
promoter, which is recognized and activated by the CcaS/CcaR two-component green-light-sensing system, to compose a vector plasmid, pKT-CS01, to achieve the induction of T7 RNAP expression only under green light illumination, with repression under red light illumination. The reporter gene, superfolder green fluorescent protein (
sf
GFP), was inserted downstream of the
T7
promoter. Transcriptional analyses revealed that T7 RNAP was induced under green light but repressed under red light. Expression of the
sf
GFP protein derived from pKT-CS01 was observed under green light illumination and was approximately 10-fold higher than that in the control transformant, which expressed
sf
GFP directly under the
cpcG2
promoter, which is directly regulated by CcaS/CcaR, under green light illumination. Comparison with the strong promoter expression systems P
cpc560
and P
trcΔlacO
revealed that the expression of
sf
GFP by the T7 RNAP system was comparable with the levels obtained with strong promoters. These results demonstrated that the green light-regulated T7 RNAP gene expression system will be a versatile tool for future technological platform to regulate gene expression in cyanobacterial bioprocesses.
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CEKLJ, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Cyanobacteria are one of the most attractive hosts for biofuel production; however, genetic approaches to regulate specific chromosomal genes in cyanobacteria remain limited. With the aim of ...developing a novel method to regulate chromosomal gene expression in cyanobacteria, we focused on riboregulatory technology. Riboregulators are composed of two RNA fragments whose interaction leads to target gene regulation with high specificity. In this study, we inserted a riboregulator sequence upstream of the chromosomal gene encoding AbrB-like transcriptional regulator, cyAbrB2, to investigate the utility of this tool. The inserted riboregulator was able to regulate
cyabrB2
gene expression, with a high ON-OFF ratio up to approximately 50-fold. The transcription levels of several genes for which cyAbrB2 acts as a transcriptional upregulator were also decreased
.
Further, the cyAbrB2 expression-repressed mutant showed high glycogen accumulation, equivalent to that in the
cyabrB2
deletion mutant (Δ
cyabrB2
). Phenotypic similarities between the
cyabrB2
expression-repressed mutant and the Δ
cyabrB2
mutant suggest that the riboregulator can potentially be used as a new chromosomal gene regulation tool in cyanobacteria.
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CEKLJ, DOBA, EMUNI, FZAB, GEOZS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NUK, OBVAL, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The pathogenicity of Clostridioides difficile in piglets remains controversial. It is unknown whether C. difficile control helps protect piglet health. To clarify the association between C. difficile ...presence and piglet diarrhea, isolates were obtained from piglets with and without diarrhea. In addition, to determine the genetic relationship of C. difficile from pigs and humans, we performed whole-genome sequencing (WGS) of C. difficile isolates. Diarrheal and non-diarrheal stool samples were collected from neonatal piglets from five farms in Japan in 2021. To clarify the relationship between C. difficile derived from pigs and those from human clinical cases, WGS of C. difficile isolates was performed. Toxin-positive C. difficile were significantly more prevalent in piglets with diarrhea, although the overall frequency of C. difficile did not differ between piglets with and without diarrhea. This observation indicates an association between toxin-positive C. difficile and diarrhea in piglets. However, further studies are needed to establish a direct causal relationship and to explore other contributing factors to diarrhea in piglets. WGS results showed that C. difficile sequence type (ST)11 including the hypervirulent PCR ribotype 078 isolates derived from Japanese pigs were closely related to ST11 of overseas strains (human clinical and animal-derived) and a Japanese human clinical strain. Toxin-positive C. difficile may cause diarrhea in piglets and hypervirulent C. difficile are spreading among pigs and human populations worldwide.
Chromosomal microarray analysis (CMA), recently introduced following conventional cytogenetic technology, can detect submicroscopic copy-number variations (CNVs) in cases previously diagnosed as ..."cytogenetically benign". At present, rapid and accurate chromosomal analysis is required in prenatal diagnostics, but prenatal CMA is not widely used due to its high price and long turnaround time. We introduced a new prenatal screening method named digital karyotyping (D-karyo), which utilizes a preimplantation genetic test for the aneuploidy (PGT-A) platform. First, we conducted a preliminary experiment to compare the original PGT-A method to our modified method. Based on the preliminary results, we decided to implement the modified strategy without whole-genome amplification (WGA) and combined it with three analytical software packages. Next, we conducted a prospective study with 824 samples. According to the indication for invasive tests, the D-karyo positive rates were 2.5% and 5.0%, respectively, in the screening positive group with NT ≥ 3.5 mm and the group with fetal abnormalities by ultrasound. D-karyo is a breakthrough modality that can detect submicroscopic CNVs ≥ 1.0 Mb accurately in only 10.5 h for 24 samples at a low cost. Implementing D-karyo as a prenatal rapid screening test will reduce unnecessary CMA and achieve more accurate prenatal genetic testing than G-banding.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
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