Melissa officinalis Extract Inhibits Herpes Simplex Virus-I Glycoprotein B Interaction with Heparin Sulfate

Herpes simplex virus 1, HSV1, is the primary cause of herpes labialis in humans. Drugslikeacycloviranditsderivativesareavailablefortreatment,butwithincreased use and the number of immune compromised patients, the development of resistance to these drugsisincreasing. Extracts of the botanical, Melissa officinalis, have previously been reported to contain antiviral activity toward HSV1. Our initial studies confirmed earlier results that constituents of Melissa officinalis interacted directly with the virus and inhibited HSV1 binding to cells during the initiation of infection. Further studies demonstrated that a component in Melissa officinalis bound specifically to the viral glycoprotein B. Virion structure was shown to be stable at low concentrations of Melissa officinalis, however at a ten-fold higher concentration than that which inhibited binding, virion structure was completely disrupted suggesting a second, virucidal, mode of inhibition. Melissa officinalis was shown to inhibit other alpha herpes viruses as well as having intermediate inhibitory activity against other viruses from the adenoviridae, poxviridae, papovaviridae, and rhabdoviridae families

In Vitro Characterization of a Nineteenth-Century Therapy for Smallpox

In the nineteenth century, smallpox ravaged through the United States and Canada. At this time, a botanical preparation, derived from the carnivorous plant Sarracenia purpurea, was proclaimed as being a successful therapy for smallpox infections. The work described characterizes the antipoxvirus activity associated with this botanical extract against vaccinia virus, monkeypox virus and variola virus, the causative agent of smallpox. Our work demonstrates the in vitro characterization of Sarracenia purpurea as the first effective inhibitor of poxvirus replication at the level of early viral transcription. With the renewed threat of poxvirus-related infections, our results indicate Sarracenia purpurea may act as another defensive measure against Orthopoxvirus infections

Regulation of Inflammatory Gene Expression in PBMCs by Immunostimulatory Botanicals

Many hundreds of botanicals are used in complementary and alternative medicine for therapeutic use as antimicrobials and immune stimulators. While there exists many centuries of anecdotal evidence and few clinical studies on the activity and efficacy of these botanicals, limited scientific evidence exists on the ability of these botanicals to modulate the immune and inflammatory responses. Using botanogenomics (or herbogenomics), this study provides novel insight into inflammatory genes which are induced in peripheral blood mononuclear cells following treatment with immunomodulatory botanical extracts. These results may suggest putative genes involved in the physiological responses thought to occur following administration of these botanical extracts. Using extracts from immunostimulatory herbs (Astragalus membranaceus, Sambucus cerulea, Andrographis paniculata) and an immunosuppressive herb (Urtica dioica), the data presented supports previous cytokine studies on these herbs as well as identifying additional genes which may be involved in immune cell activation and migration and various inflammatory responses, including wound healing, angiogenesis, and blood pressure modulation. Additionally, we report the presence of lipopolysaccharide in medicinally prepared extracts of these herbs which is theorized to be a natural and active component of the immunostimulatory herbal extracts. The data presented provides a more extensive picture on how these herbs may be mediating their biological effects on the immune and inflammatory responses

Six RNA Viruses and Forty-One Hosts: Viral Small RNAs and Modulation of Small RNA Repertoires in Vertebrate and Invertebrate Systems

We have used multiplexed high-throughput sequencing to characterize changes in small RNA populations that occur during viral infection in animal cells. Small RNA-based mechanisms such as RNA interference (RNAi) have been shown in plant and invertebrate systems to play a key role in host responses to viral infection. Although homologs of the key RNAi effector pathways are present in mammalian cells, and can launch an RNAi-mediated degradation of experimentally targeted mRNAs, any role for such responses in mammalian host-virus interactions remains to be characterized. Six different viruses were examined in 41 experimentally susceptible and resistant host systems. We identified virus-derived small RNAs (vsRNAs) from all six viruses, with total abundance varying from “vanishingly rare” (less than 0.1% of cellular small RNA) to highly abundant (comparable to abundant micro-RNAs “miRNAs”). In addition to the appearance of vsRNAs during infection, we saw a number of specific changes in host miRNA profiles. For several infection models investigated in more detail, the RNAi and Interferon pathways modulated the abundance of vsRNAs. We also found evidence for populations of vsRNAs that exist as duplexed siRNAs with zero to three nucleotide 3′ overhangs. Using populations of cells carrying a Hepatitis C replicon, we observed strand-selective loading of siRNAs onto Argonaute complexes. These experiments define vsRNAs as one possible component of the interplay between animal viruses and their hosts

Mouse Hepatitis Coronavirus A59 Nucleocapsid Protein Is a Type I Interferon Antagonist

The recent emergence of several new coronaviruses, including the etiological cause of severe acute respiratory syndrome, has significantly increased the importance of understanding virus-host cell interactions of this virus family. We used mouse hepatitis virus (MHV) A59 as a model to gain insight into how coronaviruses affect the type I alpha/beta interferon (IFN) system. We demonstrate that MHV is resistant to type I IFN. Protein kinase R (PKR) and the alpha subunit of eukaryotic translation initiation factor are not phosphorylated in infected cells. The RNase L activity associated with 2′,5′-oligoadenylate synthetase is not activated or is blocked, since cellular RNA is not degraded. These results are consistent with lack of protein translation shutoff early following infection. We used a well-established recombinant vaccinia virus (VV)-based expression system that lacks the viral IFN antagonist E3L to screen viral genes for their ability to rescue the IFN sensitivity of the mutant. The nucleocapsid (N) gene rescued VVΔE3L from IFN sensitivity. N gene expression prevents cellular RNA degradation and partially rescues the dramatic translation shutoff characteristic of the VVΔE3L virus. However, it does not prevent PKR phosphorylation. The results indicate that the MHV N protein is a type I IFN antagonist that likely plays a role in circumventing the innate immune response

<i>Astragalus membranaceus</i> treatment of PBMCs led to monocyte maturation.

<p>Part A) PBMCs (upper panels) or the monocyte cell line THP-1 (lower panel) were untreated, treated with ethanol (25%), or treated with <i>Astragalus</i> extract for 18 hours. Following treatment, unattached cells were removed and the remaining attached cells photographed. Part B) PBMCs were untreated or treated with <i>Astragalus</i> extract or PMA for 18 hours. After 18 hours, the cell culture media was removed and cells pelleted by centrifugation. The cell-free culture media was added to THP-1 cells for an additional 24 hours. Following treatment, unattached cells were removed and the remaining attached cells photographed. Part C) Cell-free media from mock-, Astragalus, or PMA-treated PBMCs was added to THP-1 cells and incubated in uncoated plastic dishes. After 48 hours, cells were washed and stained with fluorochrome-conjugated antibodies specific for CD14 and CD11b followed by flow cytometry analysis. Part D) Cell-free media obtained from PBMCs isolated from two patients were used to treat THP-1 cells and analyzed for CD14 and CD11b expression as in Part C. Values indicated represent total CD14 cells, total CD11b cells and CD14/CD11b double-positive cells. Data was normalized to mock-treated samples.</p

Host gene expression regulated by <i>Astragalus membranaceus</i> treatment of PBMCs.

<p>Genes were sorted based on a threefold (<i>P</i><0.01) or greater level of induction for <i>Astragalus</i> treated PBMCs for 18 hours (Astra column). Only genes involved in the immune/inflammatory response are shown. Changes (n-fold) in expression level relative to those of ethanol-treated cells are shown within each box. Red boxes represent genes induced 100-fold or higher, orange boxes represent genes induced 10 to 100-fold, and yellow boxes represent genes induced 3 to 10-fold. Additional botanical treatments include <i>Sambucus cerulea</i> (Sambu column) and <i>Andrographis paniculata</i> (Andro column).</p

Scatter plot representation of botanical extract regulation of gene expression.

<p>Microarray analyzed gene data was plotted to compare gene expression differences between botanical and ethanol treatment of PBMCs (Part A). Each spot on the plots represents a specific gene. Only genes with present calls in both treatments are shown. The diagonal lines off the center represent 2-, 3-, 10-, and 30-fold levels of induction or repression of gene expression. Part B illustrates comparative analysis between different botanical treatments of PBMCs.</p