[Show abstract][Hide abstract] ABSTRACT: Inflammasomes are cytoplasmic, multiprotein complexes that trigger caspase-1 activation and IL-1β maturation in response to diverse stimuli. Although inflammasomes play important roles in host defense against microbial infection, overactive inflammasomes are deleterious and lead to various autoinflammatory diseases. In the current study, we demonstrated that genipin inhibits the induction of IL-1β production and caspase-1 activation by NLRP3 and NLRC4 inflammasomes. Furthermore, genipin specifically prevented NLRP3-mediated, but not NLRC4-mediated, ASC oligomerization. Notably, genipin inhibited autophagy, leading to NLRP3 and NLRC4 inflammasome inhibition. UCP2-ROS signaling may be involved in inflammasome suppression by genipin. In vivo, we showed that genipin inhibited NLRP3-dependent IL-1β production and neutrophil flux in LPS- and alum-induced murine peritonitis. Additionally, genipin provided protection against flagellin-induced lung inflammation by reducing IL-1β production and neutrophil recruitment. Collectively, our results revealed a novel role in inhibition of inflammatory diseases for genipin that has been used as therapeutics for centuries in herb medicine.
Full-text · Article · Dec 2015 · Scientific Reports
[Show abstract][Hide abstract] ABSTRACT: Preeclampsia is a serious pregnancy-specific hypertensive syndrome that is characterized by widespread maternal endothelial dysfunction. Previous studies have shown that increased levels of circulating cell-free fetal DNA in women with preeclampsia correspond to the degree of disease severity; however, it is unknown whether this DNA is a key signal that contributes to the development of preeclampsia. The detection of DNA is critical to appropriate innate immune responses. The interferon-inducible protein 16 (IFI16) - a member of the HIN-200 family - is an innate immune receptor for intracellular DNA, which is implicated in the control of cell growth, apoptosis, angiogenesis, and immunomodulation; however, its role in preeclampsia remains unresolved. Here, we tested the hypothesis that this DNA can activate IFI16 in the placentas of women with preeclampsia and is sufficient to induce soluble fms-like tyrosine kinase 1 (sFlt-1) and soluble endoglin (sEng) production.
We characterized IFI16 in severe preeclamptic placentas and assessed whether DNA increased the release of sFlt-1 and sEng from trophoblast cells and placental explants. Furthermore, we determined whether IFI16 was involved in DNA-induced sFlt-1 and sEng production.
Placental immunoreactivity and protein levels of IFI16 were significantly increased in women with preeclampsia compared to matched control women. Treatment of human trophoblasts with the IFI16 agonist poly(dA:dT) significantly increased IFI16 levels. Furthermore, poly(dA:dT) induced sFlt-1 and sEng production by human trophoblasts in an IFI16-dependent manner.
We conclude that trophoblast cells respond to cell-free fetal DNA through the IFI16 receptor, resulting in the production of the preeclampsia-related antiangiogenic factors sFlt-1 and sEng.
Full-text · Article · May 2015 · Journal of Hypertension
[Show abstract][Hide abstract] ABSTRACT: Rabies is a viral infection of the CNS that is almost always fatal once symptoms occur. No effective treatment of the disease is available and novel antiviral strategies are urgently required. Street rabies viruses are field isolates known to be highly neurotropic. Aptamers are single-stranded oligonucleotides that bind their targets with high affinity and specificity and thus have potential for use in diagnostic and therapeutic applications. In this study, we demonstrate that the aptamers FO24 and FO21, which target RABV-infected cells, can significantly protect mice from a lethal dose of the street rabies virus FJ strain in vivo. Groups receiving preexposure prophylaxis had higher survival rates than the groups receiving postexposure prophylaxis. When mice were inoculated with aptamers (4nmol) for 24h by intracranial or intramuscular injection prior to intramuscular inoculation with the FJ strain, approximately 60% of the mice survived. These results indicate that the FO21 and FO24 aptamers may be used to develop preventative antiviral therapy against rabies disease.
No preview · Article · Apr 2014 · International immunopharmacology
[Show abstract][Hide abstract] ABSTRACT: Rabies is a fatal central nervous system (CNS) disease caused by the neurotropic rabies virus (RABV). The therapeutic management of RABV infections is still problematic, and novel antiviral strategies are urgently required. We established the RVG-BHK-21 cell line, which expresses RABV glycoprotein on the cell surface, to select aptamers. Through 28 iterative rounds of selection, single-stranded DNA (ssDNA) aptamers were generated by exponential enrichment (SELEX). A virus titer assay and a real-time quantitative reverse transcription PCR (qRT-PCR) assay revealed that four aptamers could inhibit the replication of RABV in cultured baby hamster kidney (BHK)-21 cells. However, the aptamers did not inhibit the replication of other virus, e.g., canine distemper virus (CDV) and canine parvovirus (CPV). In addition, the GE54 aptamer was found to effectively protect mice against lethal RABV challenge. After inoculation with aptamers for 24h or 48h, followed by inoculation with CVS-11, approximately 25% to 33% of the mice survived. In summary, we selected aptamers that could signiﬁcantly protect from a lethal dose of RABV in vitro and in vivo.
[Show abstract][Hide abstract] ABSTRACT: The VP2 structural protein of parvovirus can produce virus-like particles (VLPs) by a self-assembly process in vitro, making VLPs attractive vaccine candidates. In this study, the VP2 protein of canine parvovirus (CPV) was expressed using a baculovirus expression system and assembled into parvovirus-like particles in insect cells and pupae. Electron micrographs of VLPs showed that they were very similar in size and morphology when compared to the wild-type parvovirus. The immunogenicity of the VLPs was investigated in mice and dogs. Mice immunized intramuscularly with purified VLPs, in the absence of an adjuvant, elicited CD4(+) and CD8(+) T cell responses and were able to elicit a neutralizing antibody response against CPV, while the oral administration of raw homogenates containing VLPs to the dogs resulted in a systemic immune response and long-lasting immunity. These results demonstrate that the CPV-VLPs stimulate both cellular and humoral immune responses, and so CPV-VLPs may be a promising candidate vaccine for the prevention of CPV-associated disease.
[Show abstract][Hide abstract] ABSTRACT: Rabies is an acute fatal encephalitis disease that affects many warm-blooded mammals. The causative agent of the disease is Rabies virus (RABV). Currently, no approved therapy is available once the clinical signs have appeared. Aptamers, oligonucleotide ligands capable of binding a variety of molecular targets with high affinity and specificity, have recently emerged as promising therapeutic agents. In this study, sixteen high-affinity single-stranded DNA (ssDNA) aptamers were generated by cell-SELEX. Viral titer assays revealed aptamers could specifically inhibit the replication of RABV in cells but did not inhibit the replication of canine distemper virus or canine parvovirus. In addition, the FO21 and FO24 aptamers, with and without PEGylation, were found to effectively protect mice against lethal RABV challenge. When mice were inoculated with aptamers for 24 h prior to inoculation with CVS-11, approximately 87.5% of the mice survived. Here, we report aptamers that could significantly protect the mice from a lethal dose of RABV in vitro and in vivo, as demonstrated by the results for survival rate, weight loss and viral titers. These results indicate that FO21 and FO24 aptamers are a promising agent for specific antiviral against RABV infections.
[Show abstract][Hide abstract] ABSTRACT: Aptamers, functional nucleic acids, capable of binding a variety of molecular targets with high affinity and specificity, have emerged as promising therapeutic agents. In this study, the cell surface-systematic evolution of ligands by exponential enrichment (Cell-SELEX) strategy was used to generate DNA aptamers which targeted to the intact rabies virus-infected live cells. Through 35 iterative rounds of selection, five high-affinity single-stranded DNA (ssDNA) aptamers were generated by cell-SELEX. Virus titer assay and real-time quantitative reverse transcription PCR (qRT-PCR) assay revealed that all five aptamers could inhibit replication of rabies virus (RABV) in cultured baby hamster kidney (BHK)-21 cells; and T14 and F34 aptamers were most effective. The qRT-PCR also showed a dose-dependent inhibitory effect in BHK-21 cells. Collectively, these data show the feasibility of generating functionally effective aptamers against rabies virus-infected cells by the Cell-SELEX iterative procedure. These aptamers may prove clinically useful as therapeutic molecules with specific antiviral potential against RABV infections.
No preview · Article · Jul 2012 · International immunopharmacology
[Show abstract][Hide abstract] ABSTRACT: The capsid structural protein VP2 of canine parvovirus (CPV) can self-assemble into highly organized virus-like particles (VLPs) and retain major immunoreactivity. In this study, different recombinant baculoviruses that expressed varying fusion proteins of the CPV VP2 protein with the T cell determinant and/or the linear virus-neutralizing epitope of rabies virus (RV) were generated. Infection with these baculoviruses changed BmN cell morphology and inhibited their proliferation as well as damaged silkworms and pupae. However, infection with these baculoviruses induced high levels of recombinant protein expression in silkworms and pupae. More importantly, these fusion proteins self-assembled VLPs with properties similar to CPV virions and retained their VP2-specific immunoreactivity, but some retained their RV-specific immunoreactivity. Interestingly, only one fusion protein, T-VP2, maintained its haemagglutination activity. These data indicated that these insertions and replacements in the loop 2 of VP2 did not interfere with the formation of VLP, and silkworms and pupae could act as a low-costing bioreactor for the production of heterologous proteins. Therefore, our findings may provide a new framework for the development of subunit vaccines against RV and CPV.
No preview · Article · Jul 2011 · Veterinary Microbiology