kugita masanori

The live attenuated human rotavirus vaccine strain RIX4414 (Rotarix®) is used worldwide to prevent severe rotavirus-induced diarrhea in infants. This strain was attenuated through the cell culture passaging of its predecessor, human strain 89-12, which resulted in multiple genomic mutations. However, the specific molecular reasons underlying its attenuation have remained elusive, primarily due to the absence of a suitable reverse genetics system enabling precise genetic manipulations. Therefore, we first completed the sequencing of its genome and then developed a reverse genetics system for the authentic RIX4414 virus. Our experimental results demonstrate that the rescued recombinant RIX4414 virus exhibits biological characteristics similar to those of the parental RIX4414 virus, both in vitro and in vivo. This novel reverse genetics system provides a powerful tool for investigating the molecular basis of RIX4414 attenuation and may facilitate the rational design of safer and more effective human rotavirus vaccines.

Vaccine development for herpes simplex virus 2 (HSV-2) has been attempted, but no vaccines are yet available. A plasmid-based reverse genetics system for Rotavirus (RV), which can cause gastroenteritis, allows the generation of recombinant RV containing foreign genes. In this study, we sought to develop simian RV (SA11) as a vector to express HSV-2 glycoprotein D (gD2) and evaluated its immunogenicity in mice. We generated the recombinant SA11-gD2 virus (rSA11-gD2) and confirmed its ability to express gD2 in vitro. The virus was orally inoculated into suckling BALB/c mice and into 8-week-old mice. Serum IgG and IgA titers against RV and gD2 were measured by ELISA. In the 8-week-old mice inoculated with rSA11-gD2, significant increases in not only antibodies against RV but also IgG against gD2 were demonstrated. In the suckling mice, antibodies against RV were induced, but gD2 antibody was not detected. Diarrhea observed after the first inoculation of rSA11-gD2 in suckling mice was similar to that induced by the parent virus. A gD2 expressing simian RV recombinant, which was orally inoculated, induced IgG against gD2. This strategy holds possibility for genital herpes vaccine development.

BACKGROUND AND PURPOSE: High salt (HS) intake has been associated with hypertension and cognitive impairment. It is well-known that angiotensin II (Ang II)-AT1 and prostaglandin E2 (PGE2)-EP1 systems are involved in hypertension and neurotoxicity. However, the involvement of these systems in HS-mediated hypertension and emotional and cognitive impairments remains unclear. EXPERIMENTAL APPROACH: Mice were loaded with HS solution (2% NaCl drinking water) for 12 weeks and blood pressure was monitored. Subsequently, effects of HS intake on emotional and cognitive function and tau phosphorylation in the prefrontal cortex (PFC) and hippocampus (HIP) were investigated. The involvement of Ang II-AT1 and PGE2-EP1 systems in HS-induced hypertension and neuronal and behavioral impairments was examined by treatment with losartan, an AT1 receptor blocker (ARB), or EP1 gene knockout. KEY RESULTS: We demonstrated that hypertension and impaired social behavior and object recognition memory following HS intake could be associated with tau hyperphosphorylation, decreased phosphorylation of Ca2+/calmodulin-dependent protein kinase II (CaMKII), and postsynaptic density protein 95 (PSD95) expression in the PFC and HIP of mice. These changes were blocked by pharmacological treatment with losartan or EP1 gene knockout. CONCLUSIONS AND IMPLICATIONS: Our findings suggest that the interaction of Ang II-AT1 and PGE2-EP1 systems could be novel therapeutic targets for hypertension-induced cognitive impairment.

The group A rotavirus (RVA) genome comprising 11 double-stranded RNAs encodes six structural proteins (VP1-VP4, VP6, and VP7) and six non-structural proteins (NSP1-NSP6). Among these 12 rotaviral proteins, NSP6 has been less studied as to its function. We previously prepared a recombinant NSP6-deficient RVA derived from simian strain SA11-L2 by reverse genetics, and found that the NSP6-deficient virus grew well in cell culture, although its growth was less abundant than that of the parental SA11-L2 strain. In this study, we examined the potency of a recombinant RVA incapable of NSP6 expression to cause diarrhoea in suckling mice. The suckling mice infected with the NSP6-deficient virus apparently experienced diarrhoea, although the symptom was milder and the duration of diarrhoea was shorter than in the mice infected with the authentic SA11-L2 strain. Thus, together with the results obtained for cultured cells in the previous study, it can be concluded that NSP6 is not necessarily required for replication and pathogenicity in vitro and in vivo.

BACKGROUND: Cystogenesis in polycystic kidney disease (PKD) is likely accelerated by various renal insults, including crystal deposition, that activate renal tubule obstruction and dilation. We developed a capsule-based device that can be applied to cystic kidneys to restrict tubular lumen dilatation and cyst expansion. METHODS: Kidney capsule devices were designed from computed tomography images of wild-type and Cy/+ rats. Capsule devices were surgically implanted on kidneys in six surgical sessions over a period of 14 months in 7 wild-type rats of 6.5-8 weeks (3 sham operations, 2 right, 2 left) and 6 Cy/+ rats of 6.5 weeks (2 sham, 3 left, 1 bilateral). After surgery, the rats were followed for 5.4-12.4 weeks' growth and sacrificed to retrieve the kidneys. During the follow-up, serum creatinine was measured and retrieved kidneys were weighed. Histological analysis including cystic area measurement and immunohistochemistry was performed. RESULTS: Morphometric capsule devices were configured and developed by an image processing technique and produced using a 3D printer. Encapsulated Cy/+ kidneys (n = 5; mean weight 3.64 g) were consistently smaller in size (by 21-36%; p < 0.001) than unencapsulated Cy/+ kidneys (n = 7; mean weight 5.52 g). Encapsulated Cy/+ kidneys (mean %cyst area: 29.4%) showed smaller histological cystic area (by 28-58%; p < 0.001) than unencapsulated Cy/+ kidneys (mean %cyst area 48.6%). Cell proliferation and macrophages were also markedly reduced in encapsulated Cy/+ kidneys, compared to unencapsulated Cy/+ kidneys. CONCLUSIONS: We report a pilot feasibility study for the application of a novel morphometric 3D capsule device to the Cy/+ rat model showing restricted kidney volume expansion on polycystic kidney disease progression.