• Journal of Microbiology and Biotechnology
• /
• v.31 no.2
• /
• pp.226-232
• /
• 2021

Severe fever with thrombocytopenia syndrome virus (SFTSV) is an emerging phlebovirus of the Phenuiviridae family that has been circulating in the following Asian countries: Vietnam, Myanmar, Taiwan, China, Japan, and South Korea. Despite the increasing infection rates and relatively high mortality rate, there is limited information available regarding SFTSV pathogenesis. In addition, there are currently no vaccines or effective antiviral treatments available. Previous reports have shown that SFTSV suppresses the host immune response and its nonstructural proteins (NSs) function as an antagonist of type I interferon (IFN), whose induction is an essential part of the host defense system against viral infections. Given that SFTSV NSs suppress the innate immune response by inhibiting type I IFN, we investigated the mechanism utilized by SFTSV NSs to evade IFNmediated response. Our co-immunoprecipitation data suggest the interactions between NSs and retinoic acid inducible gene-I (RIG-I) or TANK binding kinase 1 (TBK1). Furthermore, confocal analysis indicates the ability of NSs to sequester RIG-I and related downstream molecules in the cytoplasmic structures called inclusion bodies (IBs). NSs are also capable of inhibiting TBK1-interferon regulatory factor 3 (IRF3) interaction, and therefore prevent the phosphorylation and nuclear translocation of IRF3 for the induction of type I IFN. The ability of SFTSV NSs to interact with and sequester TBK1 and IRF3 in IBs demonstrate an effective yet unique method utilized by SFTSV to evade and suppress host immunity.

• BMB Reports
• /
• v.34 no.5
• /
• pp.402-407
• /
• 2001

Based on the currently proposed toxicity model for the different Bacillus thuringiensis Cry $\delta$-endotoxins, their pore-forming activity involves the insertion of the ${\alpha}4-{\alpha}5$ helical hairpin into the membrane of the target midgut epithelial cell. In this study, a number of polar or charged residues in helix 4 within domain I of the 65-kDa dipteranactive Cry11A toxin, Lys-123, Tyr-125, Asn-128, Ser-130, Gln-135, Arg-136, Gln-139 and Glu-141, were initially substituted with alanine by using PCR-based directed mutagenesis. All mutant toxins were expressed as cytoplasmic inclusions in Escherichia coli upon induction with IPTG. Similar to the wild-type protoxin inclusion, the solubility of each mutant inclusion in the carbonate buffer, pH 9.0, was relatively low When E. coli cells, expressing each of the mutant proteins, were tested for toxicity against Aedes aegypti mosquito-larvae, toxicity was completely abolished for the alanine substitution of arginine at position 136. However, mutations at the other positions still retained a high level of larvicidal activity Interestingly, further analysis of this critical arginine residue by specific mutagenesis showed that conversions of arginine-136 to aspartate, glutamine, or even to the most conserved residue lysine, also abolished the wild-type activity The results of this study revealed an important determinant in toxin function for the positively charged side chain of arginine-136 in helix 4 of the Cry11A toxin.

• The Korean Journal of Pharmacology
• /
• v.30 no.1
• /
• pp.117-124
• /
• 1994

Phospholamban is the regulator of $Ca^{2+}-ATPase$ in cardiac sarcoplasmic reticulum(SR). The mechanism of regulation appears to involve inhibition by dephosphorylated phospholamban. Phosphorylation of phospholamban relieves this inhibition. Recently, there has been a report that the cytoplasmic domain (amino acids 1-25) of phospholamban is insufficient to inhibit the $Ca^{2+}$ pump. To explore the domains of phospholamban responsible for $Ca^{2+}-ATPase$ inhibitory activity, we examined the effect of a synthetic phospholamban peptide consisting of amino acid residues 1-25 on $Ca^{2+}$ uptake by reconstituted skeletal SR $Ca^{2+}-ATPase$. The $Ca^{2+}-ATPase$ of skeletal SR was purified and reconstituted in proteoliposomes containing phosphatidylcholine (PC) or phosphatidylcholine: phosphatidylserine (PC:PS). Inclusion of a phospholamban peptide in PC proteoliposomes was associated with significant inhibition of the initial rates of $Ca^{2+}$ uptake at pCa 6.0, and phosphorylation of this peptide by the catalytic subunit of cAMP-dependent protein kinase reversed the inhibitory effect on the $Ca^{2+}$ pump. Similar effects of phospholamban peptide were also observed using PC:PS proteoliposomes. Based on these results, we could conclude that the cytoplasmic domain of phospholamban, containing the phosphorylation sites, by itself is sufficient to inhibit the $Ca^{2+}$ pump of SR.

• The Plant Pathology Journal
• /
• v.27 no.2
• /
• pp.187-190
• /
• 2011

Symptoms induced in the leaves of strawberry (Fragaria x ananassa Duch.), 'Seolhyang' and 'Eyeberry', were mosaic, distortion and black colored edge on leaves at Nonsan area, one of the important production areas in Korea. Electron microscopy by quick-dip revealed the flexuous rod-shape particles having about 550-600 nm length. Cytoplasmic inclusion bodies composed of aggregated virus particles were observed frequently in mesophyll parenchyma and epidermal cells for the leaves of strawberry. The specific primers amplifying products of 635 bp and 729 bp were developed for RT-PCR detection of Strawberry mild yellow edge virus (SMYEV). Nucleotide identity of the CP gene of SMYEV was 92.8-99.2% with those of other SMYEV isolates from Gen-Bank database.

• Korean Journal of Veterinary Service
• /
• v.15 no.1
• /
• pp.67-80
• /
• 1992

Avian reoviruses have been implicated in respiratory disease enteric conditions including Cloacal pasting in young thicks, pericarditis, hydropericardium, anaemia with swollen spleen and liver and petechiation of skeletal muscle and viral arthritis. This study was conducted to examine properties of reovirus field 3 strains isolated from affected broiler from several farms. An infectious agent was isolated from leg tendons and intestine of broiler with clinical tenosynovitis. The agent grew well on the chicken embryo kideny cells(CEK). One of them produced cytopathic effects(CPE) of round type and formed intranuclear inclusions, and the other was characterized by CPE of syncytical type and cytoplasmic inclusion. The properties and serological classification of field strains were examined by hemagglutin test, virus neutralization test, agar gel precipitin, electropherotype. They showed no hemagglutination reactions and not well neutralization and to possess common antigens detectable by AGP test. RNA electropherotype presented 10 segment band as the previous report. These data suggest that the field strains and standard strains (1133, 1733) may be the same group.

• Proceedings of the Korean Society of Plant Pathology Conference
• /
• 2003.10a
• /
• pp.127.2-127
• /
• 2003

YMV-K strains were purified from D. oppostita Thunb. tv. Dung-Gun-Ma showing mosaic symptom on their leaves. YMV-K strains were filamentous particles of 780nm in length and induced cytoplasmic disorder such as inclusion body formation. Nucleotide and amino acid sequences of 5'-UTR, Pl and CP of YMV-K strains shared 80.8, 64.7 and 98.3％ identity respectively to JYMV J1 in the mean value. Purification of YMV-K strains according to JYMV purification method(S. Fuji) was conducted to product antiserum. With antiserum against YMV-K strains, the Various diagnosis methods such as IC-RT-PCR, DIBA, RIPA and indirect-ELISA were used to detect YMV-K strains in Chinese yam plant.

• Journal of Sericultural and Entomological Science
• /
• v.18 no.2
• /
• pp.83-88
• /
• 1976

A study was made on the interstrain difference in dose-infection response and induction response of silkworm to the two strains of cytoplasmic polyhedrosis virus to obtain some informations on screening the leading strains. Comparison of dose-infection responses of larvae following the inoculation of the inclusion body of cytoplasmic polyhedrosis virus revealed that there is no significance in the resistance to dose-infection and any of strains were more resistant at advanced stage(4th instar) than younger stage(2nd instar). In the pathogenicity between cytoplasmic polyhedrosis virus with hexagonal and tetragonal outline, the hexagonal polyhedra showed higher pathogenicity than the tetragonal polyhedra. However, the averages of $LC_{50}$ of cytoplasmic polyhedrosis virus with hexagonal outline to larvae of parental inbred line were 6.12${\times}$10$\^$6//$m\ell$ at 2nd instar and 1.57${\times}$10$\^$7//$m\ell$ at 4th instar in spring and those to their hybrids were 1.28${\times}$10$\^$6//$m\ell$ at 2nd ins tar and 4.99${\times}$10$\^$6//$m\ell$ at 4th ins tar in autumn. Meanwhile the $LC_{50}$ averages of tetragonal polyhedra. to larvae of parental inbred line were 2.06${\times}$10$\^$7//$m\ell$ at 2nd instar and 5.67${\times}$10$\^$7//$m\ell$ at 4th instar in spring and those to their hybrids were 9.84${\times}$10$\^$6//$m\ell$ at 2nd instar and 3.86${\times}$10$\^$7//$m\ell$ at 4th instar in autumn, respectively. In comparison of induction response of silkworm larvae to inoculation of tetragonal polyhedra of cytoplasmic polyhedrosis virus, the induction rate of hexagonal polyhedra was remarkably higher in the treatment of inoculation at 2nd instar than at 4th instar and at the concentration of 1.3${\times}$10$\^$6//$m\ell$ than at any others. Most of induction showed a mixed infection with hexagonal and tetragonal polyhedra of cytoplasmic polyhedrosis virus.

• Applied Microscopy
• /
• v.24 no.2
• /
• pp.105-114
• /
• 1994

Comparative ultrastructural studies of sorghum (Sorghum bicolor L. Moench) cultivar (cv.) HOK and cv Pioneer 8680 leaf cells separately infected with maize dwarf mosaic virus (MDMV) strain A and B, respectively, revealed the formation of numerous cylindrical inclusions in both cross and longitudinal sections. The MDMV-A and -B were distinguished by the presence or absence of specific inclusion bodies in the cytoplasm. Electron microscope revealed the presence of pinwheels, bundles, scrolls, and laminated aggregates in Pioneer 8680 sorghum leaf cells infected with MDMV-B while no laminated aggregates were found in cells of HOK sorghum leaf cells infected with MDMV-A. Differences in the ultrastructure of cylindrical inclusions between two strains of MDMV, especially with respect to laminated aggregates, have been morphologically indexed to classify potyviruses into subdivision. The presence of laminated aggregates may be assigned to subdivision III while the absence of laminated aggregates is assigned to subdivision I. These variations of structures associated with cylindrical inclusions appeared virus-specific inductions and may be represented the morphogenesis of inclusion bodies following development of infections.

• Korean Journal of Veterinary Service
• /
• v.13 no.2
• /
• pp.162-183
• /
• 1990

From 1988 to 1989, 8 strains of canine parvovirus-2 (CPV-2) were isolated from the fecal specimens from the dogs that were clinically diagnosed as canine parvoviral enteritis in the veterinary hospitals located in the regions of Taejon and Chungbuk province. Studios on biological and physicochemical properties for the isolates were carried out. The results obtained by experiments are summarized as follows. 1. Among 62 fecal samples collected from the dogs with enteric diseases, 24 (38.7%) showed the haemagglutinating activity against porcine erythrocyte, ranging from 16 to 16, 384 of HA titers. 2. When 8 fecal specimens with high HA titer over 1, 000 were inocultated into CRFX cells, intranuclear inclusion bodies were obseverd in all of eight specimens, of w)lick three specimens showed cytoplasmic inclusions concurrently with the intranuclear inclusion bodies. 3. In study on species-specificity of haemagglutinating activity of the isolates, TJ-89-1 and TJ-89-2, it was found that the isolates revealed the highest haemagglutinating activity with porcine erythrocytes, showing the relatively lower haemagglutination titers with the erythrocytes from cat and rabbit. None of erythrocytes from other animals reacted with the isolates. 4. By the cross-haemagglutination inhibition test of the Isolates with reference viruses and sera, the Isolates were evidently identified as the strains of canine parvovirus-2. 5. In Physicochemical property test, it was evident that the isolates were stable in, lipid solvent, pH and heat treatment at $56^{\circ}C$ for 30 min. and contain DNA genome. 6. When seven puppies were inoculated intraorally with the isolate at HA titer of 8, 192, all of the puppies showed the symptoms of anorexia, vomiting, diarrhea and died at the 5th to 10th days post inoculation(pi). The fecal samples from all of the puppies revealed significantly high HA titers afterward the 5th days pi. Body temperature and the number of total leucocytes were slightly increased at the early stage of infection. but extremely decreased at the stage of collapse. HI titers of the sera started to increase at the 2nd to 3rd days pi reaching 512 to 1, 024 at the 4th to 5th day pi.

• Biomolecules & Therapeutics
• /
• v.29 no.1
• /
• pp.83-89
• /
• 2021

Multiple system atrophy (MSA) is a neurodegenerative disease characterized by presence of α-synuclein-positive inclusions in the cytoplasm of oligodendrocytes. These glial cytoplasmic inclusions (GCIs) are considered an integral part of the pathogenesis of MSA, leading to demyelination and neuronal demise. What is most puzzling in the research fields of GCIs is the origin of α-synuclein aggregates in GCIs, since adult oligodendrocytes do not express high levels of α-synuclein. The most recent leading hypothesis is that GCIs form via transfer and accumulation of α-synuclein from neurons to oligodendrocytes. However, studies regarding this subject are limited due to the absence of proper human cell models, to demonstrate the entry and accumulation of neuronal α-synuclein in human oligodendrocytes. Here, we generated mature human oligodendrocytes that can take up neuronderived α-synuclein and form GCI-like inclusions. Mature human oligodendrocytes are derived from neural stem cells via "oligosphere" formation and then into oligodendrocytes, treating the cells with the proper differentiation factors at each step. In the final cell preparations, oligodendrocytes consist of the majority population, while some astrocytes and unidentified stem cell-like cells were present as well. When these cells were exposed to α-synuclein proteins secreted from neuron-like human neuroblastoma cells, oligodendrocytes developed perinuclear inclusion bodies with α-synuclein immunoreactivity, resembling GCIs, while the stem cell-like cells showed α-synuclein-positive, scattered puncta in the cytoplasm. In conclusion, we have established a human oligodendrocyte model for the study of GCI formation, and the characterization and use of this model might pave the way for understanding the pathogenesis of MSA.