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101.
William A Cafruny Richard G Duman Grace HW Wong Suleman Said Pam Ward-Demo Raymond RR Rowland Eric A Nelson 《Virology journal》2006,3(1):1-17
Background
Porcine reproductive and respiratory syndrome virus (PRRSV) is the etiologic agent of PRRS, causing widespread chronic infections which are largely uncontrolled by currently available vaccines or other antiviral measures. Cultured monkey kidney (MARC-145) cells provide an important tool for the study of PRRSV replication. For the present study, flow cytometric and fluorescence antibody (FA) analyses of PRRSV infection of cultured MARC-145 cells were carried out in experiments designed to clarify viral dynamics and the mechanism of viral spread. The roles of viral permissiveness and the cytoskeleton in PRRSV infection and transmission were examined in conjunction with antiviral and cytotoxic drugs.Results
Flow cytometric and FA analyses of PRRSV antigen expression revealed distinct primary and secondary phases of MARC-145 cell infection. PRRSV antigen was randomly expressed in a few percent of cells during the primary phase of infection (up to about 20–22 h p.i.), but the logarithmic infection phase (days 2–3 p.i.), was characterized by secondary spread to clusters of infected cells. The formation of secondary clusters of PRRSV-infected cells preceded the development of CPE in MARC-145 cells, and both primary and secondary PRRSV infection were inhibited by colchicine and cytochalasin D, demonstrating a critical role of the cytoskeleton in viral permissiveness as well as cell-to-cell transmission from a subpopulation of cells permissive for free virus to secondary targets. Cellular expression of actin also appeared to correlate with PRRSV resistance, suggesting a second role of the actin cytoskeleton as a potential barrier to cell-to-cell transmission. PRRSV infection and cell-to-cell transmission were efficiently suppressed by interferon-γ (IFN-γ), as well as the more-potent experimental antiviral agent AK-2.Conclusion
The results demonstrate two distinct mechanisms of PRRSV infection: primary infection of a relatively small subpopulation of innately PRRSV-permissive cells, and secondary cell-to-cell transmission to contiguous cells which appear non-permissive to free virus. The results also indicate that an intact cytoskeleton is critical for PRRSV infection, and that viral permissiveness is a highly efficient drug target to control PRRSV infection. The data from this experimental system have important implications for the mechanisms of PRRSV persistence and pathology, as well as for a better understanding of arterivirus regulation. 相似文献102.
We report a reverse thermogelling poly(ethylene oxide-b-propylene oxide-b-ethylene oxide) disulfide multiblock copolymer as a thiol-sensitive biodegradable polymer. The poly(ethylene oxide-b-propylene oxide-b-ethylene oxide) aqueous solutions studied in this research underwent sol-gel-sol or sol-gel-sol-gel transition depending on the molecular weight and concentration of the polymer, whereas the corresponding disulfide multiblock copolymer aqueous solutions underwent sol-gel transition as the temperature increased in a range of 0-60 degrees C. The hydrophobic dye solubilization and dynamic light scattering of the polymer aqueous solution suggest that the poly(ethylene oxide-b-propylene oxide-b-ethylene oxide)s undergo unimer (3 nm) to micelle (12 nm) transition, whereas the disulfide multiblock copolymers undergo unimer (6 nm) to aggregated polymer (600 nm) transition as the temperature increases. The gel duration increased from 6 h (poly(ethylene oxide-b-propylene oxide-b-ethylene oxide)) to more than 12 days (the corresponding disulfide multiblock copolymer) in phosphate buffer saline, and the gel duration of the latter depended on the glutathione concentration of the medium. The model drug, paclitaxel, was released from the in-situ-formed poly(ethylene oxide-b-propylene oxide-b-ethylene oxide) disulfide multiblock copolymer gel in a glutathione concentration-sensitive manner. 相似文献
103.
Hye-Yeong Kim Johann Sohn Gihani T. Wijewickrama Praneeth Edirisinghe Teshome Gherezghiher Madhubani Hemachandra Pei-Yi Lu R. Esala Chandrasena Mary Ellen Molloy Debra A. Tonetti Gregory R.J. Thatcher 《Bioorganic & medicinal chemistry》2010,18(2):809-821
Cyclodextrin (CD) is a well known drug carrier and excipient for enhancing aqueous solubility. CDs themselves are anticipated to have low membrane permeability because of relatively high hydrophilicity and molecular weight. CD derivatization with 17-beta estradiol (E2) was explored extensively using a number of different click chemistries and the cell membrane permeability of synthetic CD–E2 conjugate was explored by cell reporter assays and confocal fluorescence microscopy. In simile with reported dendrimer–E2 conjugates, CD–E2 was found to be a stable, extranuclear receptor selective estrogen that penetrated into the cytoplasm. 相似文献
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106.
Myoung-Hee Kwon Hyung-Hwan Kim Ho-Sa Lee Tong-Soo Kim Yong-Joo Ahn Youngjoo Sohn Hyeong-Woo Lee 《Experimental parasitology》2010,126(2):217-223
The merozoite surface protein-1 (MSP-1) from Plasmodium vivax was evaluated as an oral vaccine candidate by cloning and expressing the interspecies conserved block 10 (ICB10) of the MSP-1 from a Korean isolate in Escherichia coli. The expressed fusion protein contained ICB10 and a maltose-binding protein (MBP), rPv54, has a molecular weight of approximately 54 kDa as determined by SDS-PAGE analysis. IgG against rPv54 was successfully produced in BALB/c mice by oral immunization and sustained for more than 4 months. IgG2b was dominantly produced in both oral and parenteral immunizations. The rPv54 increased the frequency of NK, NKT, CD4+ T, CD8+ T, and B cells in both immunizations. IL-5 and TNF-α were increased in both significantly. In conclusion, rPv54 might be a valuable potential vaccine candidate for the oral and parenteral immunization against vivax malaria. 相似文献
107.
Cheon H Rho YH Choi SJ Lee YH Song GG Sohn J Won NH Ji JD 《Journal of immunology (Baltimore, Md. : 1950)》2006,177(2):1092-1100
In inflamed joints of rheumatoid arthritis, PGE(2) is highly expressed, and IL-10 and IL-6 are also abundant. PGE(2) is a well-known activator of the cAMP signaling pathway, and there is functional cross-talk between cAMP signaling and the Jak-STAT signaling pathway. In this study, we evaluated the modulating effect of PGE(2) on STAT signaling and its biological function induced by IL-10 and IL-6, and elucidated its mechanism in THP-1 cells. STAT phosphorylation was determined by Western blot, and gene expression was analyzed using real-time PCR. Pretreatment with PGE(2) significantly augmented IL-10-induced STAT3 and STAT1 phosphorylation, as well as suppressors of cytokine signaling 3 (SOCS3) and IL-1R antagonist gene expression. In contrast, PGE(2) suppressed IL-6-induced phosphorylation of STAT3 and STAT1. These PGE(2)-induced modulating effects were largely reversed by actinomycin D. Pretreatment with dibutyryl cAMP augmented IL-10-induced, but did not change IL-6-induced STAT3 phosphorylation. Misoprostol, an EP2/3/4 agonist, and butaprost, an EP2 agonist, augmented IL-10-induced STAT3 phosphorylation and SOCS3 gene expression, but sulprostone, an EP1/3 agonist, had no effect. H89, a protein kinase A inhibitor, and LY294002, a PI3K inhibitor, diminished PGE(2)-mediated augmentation of IL-10-induced STAT3 phosphorylation. In this study, we found that PGE(2) selectively regulates cytokine signaling via increased intracellular cAMP levels and de novo gene expression, and these modulating effects may be mediated through EP2 or EP4 receptors. PGE(2) may modulate immune responses by alteration of cytokine signaling in THP-1 cells. 相似文献
108.
Jong Il Rhee Tae-Hyoung Kang Kum-Il Lee Ok-Jae Sohn Sun-Yong Kim Sang-Wook Chung 《Biotechnology and Bioprocess Engineering》2006,11(5):432-441
2D fluorescence sensors produce a great deal of spectral data during fermentation processes, which can be analyzed using a
variety of statistical techniques. Principal component analysis (PCA) and a self-organizing map (SOM) were used to analyze
these 2D fluorescence spectra and to extract useful information from them. PCA resulted in scores and loadings that were visualized
in the score-loading plots and used to monitor various fermentation processes with recombinantEscherichia coli andSaccharomyces cerevisiae. The SOM was found to be a useful and interpretative method of classifying the entire gamut of 2D fluorescence spectra and
of selecting some significant combinations of excitation and emission wavelengths. The results, including the normalized weights
and variances, indicated that the SOM network is capable of being used to interpret the fermentation processes monitored by
a 2D fluorescence sensor. 相似文献
109.
110.
Tetracycline-induced proteome of Pseudomonas putida KT2440 was analyzed by 2-D gel electrophoresis and matrix-assisted laser desorption ionization–time of flight/mass spectrum
(NALDI-TOF/MS) in order to understand cellular response to tetracycline. Of the proteins upregulated in a culture medium containing
subinhibitory concentration of tetracycline (50 μg/mL), we identified 38 proteins from cytosol and precipitated fractions
by peptide mass fingerprinting and mass spectrum/mass spectrum analysis. Various amino acids ABC transporters, a ribose ABC
transporter, and a sulfate ABC transporter were found to be upregulated. Protein synthesis-related proteins, stress proteins,
energy metabolic enzymes, and unknown proteins were also strongly induced. Of the identified upregulated proteins, several
proteins (isocitrate lyase, branched-chain amino acid ABC transporter, superoxide dismutase, etc.) were also upregulated under
phenol-induced stress condition. These results demonstrate that tetracycline at a high concentration induced comprehensive
stress in P. putida KT2440 and the global induction of proteins related to bacteria survival. Proteome analysis was found to be a useful tool
for the elucidation of antibiotic-induced proteins in the present study. 相似文献