24 research outputs found
Modulation of bovine herpesvirus 1 infection by virally encoded microRNAs
No full textBovine herpesvirus 1 (BoHV-1), is a member of the subfamily Alphaherpesvirinae in the order Herpesviridae and is a ubiquitous pathogen of cattle responsible for significant economic loss worldwide. The BoHV-1 genome encodes at least 10 BoHV-1 microRNA (miRNA) genes, whose functions remain poorly understood. This study sought to understand the role of three BoHV-1 miRNA genes, Bhv1-miR-B6, Bhv1-miR-B8 and Bhv1-miR-B9, which are located proximal to the BoHV-1 origins of replication (OriS). Therefore, plasmids expressing the precursor miRNA hairpins for the Bhv1-miR-B6, Bhv1-miR-B8, and Bhv1-miR-B9 genes were constructed and transfected into Madin-Darby bovine kidney cells prior to BoHV-1 infection. Interestingly, transient expression of either Bhv1-miR-B8 or Bhv1-miR-B9 in Madin-Darby bovine kidney cells prior to infection resulted in partial suppression of BoHV-1 replication, quantified through estimating levels of glycoprotein C mRNA and protein levels. Putative interactions between the mature miRNA bhv1-miR-B8-3p and bhv1-miR-B9 and BoHV-1 transcripts were identified providing plausible pathways for these molecules to affect virus replication. Therefore, these two miRNAs are implicated in the post-transcriptional regulation of BoHV-1 transcripts important for virus replication and could be used to limit BoHV-1 replication
Anti-Malassezia globosa (MYA-4889, ATCC) activity of Thai propolis from the stingless bee Geniotrigona thoracica
No full textMalassezia globosa, a lipophilic pathogen, is known to be involved in various chronic skin diseases. Unfortunately, the available treatments have unwanted side effects and microbial drug resistance is evolving. As the antimicrobial activity of propolis is outstanding, this study aimed to examine the potential of propolis from the stingless bee Geniotrigona thoracica against the yeast. Anti-M. globosa growth activity was ascertained in agar well diffusion and broth microdilution assays and the inhibitory concentration value at 50 % (IC50) was determined. Since the yeast cannot synthesize its own fatty acids, extracellular lipase is important for its survival. Here, anti-M. globosa extracellular lipase activity was additionally investigated by colorimetric and agar-based methods. Compared to the crude hexane and crude dichloromethane extracts, the crude methanol partitioned extract (CMPE) exhibited the best anti-M. globosa growth activity with an IC50 of 1.22 mg/mL. After CMPE was further enriched by silica gel column chromatography, fraction CMPE1 (IC50 of 0.98 mM or 184.93 μg/mL) presented the highest activity and was later identified as methyl gallate (MG) by nuclear magnetic resonance analysis. Subsequently, MG was successfully synthesized and shown to have a similar activity, and a minimal fungicidal concentration of 43.44 mM or 8.00 mg/mL. However, lipase assay analysis suggested that extracellular lipase might not be the main target mechanism of MG. This is the first report of MG as a new anti-Malassezia compound. It could be a good candidate for further developing alternative therapeutic agents
Simultaneous Production of a Virus-Like Particle Linked to dsRNA to Enhance dsRNA Delivery for Yellow Head Virus Inhibition
No full textA co-expressed Penaeus stylirostris densovirus (PstDNV) capsid and dsRNA specific to the yellow head virus (YHV) protease (CoEx cpPstDNV/dspro) has been shown to suppress YHV replication in the Pacific white-legged shrimp (Litopenaeus vannamei). However, maintaining two plasmids in a single bacterial cell is not desirable; therefore, a single plasmid harboring both the PstDNV capsid and the dsRNA-YHV-pro gene was constructed under the regulation of a single T7 promoter, designated pET28a-Linked cpPstDNV-dspro. Following induction, this novel construct expressed an approximately 37-kDa recombinant protein associated with a roughly 400-bp dsRNA (Linked cpPstDNV-dspro). Under a transmission electron microscope, the virus-like particles (VLP; Linked PstDNV VLPs-dspro) obtained were seen to be monodispersed, similar to the native PstDNV virion. A nuclease digestion assay indicated dsRNA molecules were both encapsulated and present outside the Linked PstDNV VLPs-dspro. In addition, the amount of dsRNA produced from this strategy was higher than that obtained with a co-expression strategy. In a YHV infection challenge, the Linked PstDNV VLPs-dspro was more effective in delaying and reducing mortality than other constructs tested. Lastly, the linked construct provides protection for the dsRNA cargo from nucleolytic enzymes present in the shrimp hemolymph. This is the first report of a VLP carrying virus-inhibiting dsRNA that could be produced without disassembly and reassembly to control virus infection in shrimp
<i>In vitro</i>assembly of<i>Penaeus monodon</i>densovirus (<i>Pm</i>DNV)-like particles produced in a prokaryote expression system
No full textStrain Variation Can Significantly Modulate the miRNA Response to Zika Virus Infection
No full textZika virus (ZIKV) is a mosquito-transmitted virus that has emerged as a major public health concern due to its association with neurological disorders in humans, including microcephaly in fetuses. ZIKV infection has been shown to alter the miRNA profile in host cells, and these changes can contain elements that are proviral, while others can be antiviral in action. In this study, the expression of 22 miRNAs in human A549 cells infected with two different ZIKV isolates was investigated. All of the investigated miRNAs showed significant changes in expression at at least one time point examined. Markedly, 18 of the miRNAs examined showed statistically significant differences in expression between the two strains examined. Four miRNAs (miR-21, miR-34a, miR-128 and miR-155) were subsequently selected for further investigation. These four miRNAs were shown to modulate antiviral effects against ZIKV, as downregulation of their expression through anti-miRNA oligonucleotides resulted in increased virus production, whereas their overexpression through miRNA mimics reduced virus production. However, statistically significant changes were again seen when comparing the two strains investigated. Lastly, candidate targets of the miRNAs miR-34a and miR-128 were examined at the level of the mRNA and protein. HSP70 was identified as a target of miR-34a, but, again, the effects were strain type-specific. The two ZIKV strains used in this study differ by only nine amino acids, and the results highlight that consideration must be given to strain type variation when examining the roles of miRNAs in ZIKV, and probably other virus infections
Studies of the in vitro cytotoxic, antioxidant, lipase inhibitory and antimicrobial activities of selected Thai medicinal plants
No full textIn vitro neutralization of yellow head virus infection in shrimp using recombinant PmYRP65 protein
No full textExpression profile of selected genes of the E-11 cell line in response to red-spotted grouper nervous necrosis virus infection
No full textMost fish species are susceptible to red-spotted grouper nervous necrosis virus (RGNNV) which causes viral encephalopathy and retinopathy leading to huge financial losses in the aquaculture farming industry for decades. A knowledge of RGNNV replication and the host response in depth is warranted to understand the host-virus interaction and to develop an effective approach to inhibit this virus. This study therefore aimed to investigate the expression of selected immune and stress-related genes of the E-11 clonal cell line upon RGNNV infection. The results showed significant upregulation of viperin, hsp70 and tnfaip3 transcripts at 48 h post infection, while the transcript abundance of irf3, cc chemokine, hsp30 showed increases which did not reach significance and tnf-α showed no change in expression in response to infection. This study highlights the involvement of viperin, hsp70 and tnfaip3 during RGNNV infection of E-11 cells which provides a clearer understanding of the pathogenic mechanism of the disease
Administration of co-expressed Penaeus stylirostris densovirus-like particles and dsRNA-YHV-Pro provide protection against yellow head virus in shrimp
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