scholarly journals Potentiation of pest control by insect immunosuppression

2004 ◽  
Author(s):  
Nor Chejanovsky ◽  
Bruce A. Webb
Keyword(s):  
Immune Response ◽  
Cell Line ◽  
Virus Replication ◽  
Pest Control ◽  
Molecular Mechanisms ◽  
Insect Pest ◽  
Insect Immunity ◽  
Viral Pathogen ◽  
Baculovirus Infection ◽  
One Year

Our original aims were to elucidate the mechanisms through which the immunosuppressive insect virus, the Campoletis sonorensis polydnavirus (CsV) promotes replication of a well-characterized pathogenic virus, the Autographa californica multiple nucleopolyhedrovirus (AcMNPV) in hosts that are mildly or non-permissive to virus replication. According to the BARD panels criticism we modified our short-term goals (see below). Thus, in this feasibility study (one-year funding) we aimed to show that: 1. S. littoralis larvae mount an immune response against a baculovirus infection. 2. Immunosuppression of an insect pest improves the ability of a viral pathogen (a baculovirus) to infect the pest. 3. S. littoralis cells constitute an efficient tool to study some aspects of the anti- viral immune response. We achieved the above objectives by: 1. Finding melanized viral foci upon following the baculoviral infection in S . littoralis larvae infected with a polyhedra - positive AcMNPV recombinant that expressed the GFP gene under the control of the Drosophila heat shock promoter. 2. Studying the effect of AcMNPV-infection in S . littoralis immunosuppressed by parasitation with the Braconidae wasp Chelonus inanitus that bears the CiV polydna virus, that resulted in higher susceptibility of S. littoralis to AcMNPV- infection. 3. Proving that S. littoralis hemocytes resist AcMNPV -infection. 4. Defining SL2 as a granulocyte-like cell line and demonstrating that as littoralis hemocytic cell line undergoes apoptosis upon AcMNPV -infection. 5. Showing that some of the recombinant AcMNPV expressing the immuno-suppressive polydna virus CsV- vankyrin genes inhibit baculoviral-induced lysis of SL2 cells. This information paves the way to elucidate the mechanisms through which the immuno- suppressive polydna insect viruses promote replication of pathogenic baculoviruses in lepidopteran hosts that are mildly or non-permissive to virus- replication by: - Assessing the extent to which and the mechanisms whereby the immunosuppressive viruses, CiV and CsV or their genes enhance AcMNPV replication in polydnavirus- immunosuppressed H. zea and S. littoralis insects and S. littoralis cells. - Identifying CiV and CsV genes involved in the above immunosuppression (e.g. inhibiting cellular encapsulation and disrupting humoral immunity). This study will provide insight to the molecular mechanisms of viral pathogenesis and improve our understanding of insect immunity. This knowledge is of fundamental importance to controlling insect vectored diseases of humans, animals and plants and essential to developing novel means for pest control (including baculoviruses) that strategically weaken insect defenses to improve pathogen (i.e. biocontrol agent) infection and virulence.

scholarly journals Potentiation of Pest Control by Insect Immunosuppression

2010 ◽  
Author(s):  
Nor Chejanovsky ◽  
Bruce A. Webb
Keyword(s):  
Immune Response ◽  
Pest Control ◽  
Insect Pest ◽  
Insect Pathogen ◽  
Viral Pathogen ◽  
Antiviral Immune Response ◽  
Baculovirus Infection ◽  
Insect Populations ◽  
Insect Immune Response ◽  
First Time

The restricted host range of many baculoviruses, highly pathogenic to Lepidoptera and non-pathogenic to mammals, limits their use to single or few closely related Lepidopteran species and is an obstacle to extending their implementation for pest control. The insect immune response is a major determinant of the ability of an insect pathogen to efficiently multiply and propagate. We have developed an original model system to study the Lepidopteran antiviral immune response based on Spodoptera littoralis resistance to AcMNPV (Autographa californica multiple nucleopolyhedrovirus) infection and the fascinating immunosuppressive activity of polydnaviruses .Our aim is to elucidate the mechanisms through which the immunosuppressive insect polydnaviruses promote replication of pathogenic baculoviruses in lepidopteran hosts that are mildly or non-permissive to virus- replication. In this study we : 1- Assessed the extent to which and the mechanisms whereby the immunosuppressive Campoletis sonorensis polydnavirus (CsV) or its genes enhanced replication of a well-characterized pathogenic baculovirus AcMNPV, in polydnavirus-immunosuppressedH. zea and S. littoralis insects and S. littoralis cells, hosts that are mildly or non-permissive to AcMNPV. 2- Identified CsV genes involved in the above immunosuppression (e.g. inhibiting cellular encapsulation and disrupting humoral immunity). We showed that: 1. S. littoralis larvae mount an immune response against a baculovirus infection. 2. Immunosuppression of an insect pest improves the ability of a viral pathogen, the baculovirus AcMNPV, to infect the pest. 3. For the first time two PDV-specific genes of the vankyrin and cystein rich-motif families involved in immunosuppression of the host, namely Pvank1 and Hv1.1 respectively, enhanced the efficacy of an insect pathogen toward a semipermissive pest. 4. Pvank1 inhibits apoptosis of Spodopteran cells elucidating one functional aspect of PDVvankyrins. 5. That Pvank-1 and Hv1.1 do not show cooperative effect in S. littoralis when co-expressed during AcMNPV infection.   Our results pave the way to developing novel means for pest control, including baculoviruses, that rely upon suppressing host immune systems by strategically weakening insect defenses to improve pathogen (i.e. biocontrol agent) infection and virulence. Also, we expect that the above result will help to develop systems for enhanced insect control that may ultimately help to reduce transmission of insect vectored diseases of humans, animals and plants as well as provide mechanisms for suppression of insect populations that damage crop plants by direct feeding. 

scholarly journals The Molecular Basis of Phospholipase D2-Induced Chemotaxis: Elucidation of Differential Pathways in Macrophages and Fibroblasts

2010 ◽  
Vol 30 (18) ◽  
pp. 4492-4506 ◽  
Author(s):  
Katie Knapek ◽  
Kathleen Frondorf ◽  
Jennalee Post ◽  
Stephen Short ◽  
Dianne Cox ◽  
...  
Keyword(s):  
Immune Response ◽  
Cell Migration ◽  
Growth Factor ◽  
Cell Line ◽  
Protein Interactions ◽  
Wound Repair ◽  
Molecular Mechanisms ◽  
Growth Factor Receptor ◽  
Cell Transfection ◽  
Phospholipase D1

ABSTRACT We report the molecular mechanisms that underlie chemotaxis of macrophages and cell migration of fibroblasts, cells that are essential during the body's innate immune response and during wound repair, respectively. Silencing of phospholipase D1 (PLD1) and PLD2 reduced cell migration (both chemokinesis and chemotaxis) by ∼60% and >80%, respectively; this migration was restored by cell transfection with PLD2 constructs refractory to small interfering RNA (siRNA). Cells overexpressing active phospholipase D1 (PLD1) but, mostly, active PLD2 exhibited cell migration capabilities that were elevated over those elicited by chemoattractants alone. The mechanism for this enhancement is complex. It involves two pathways: one that is dependent on the activity of the lipase (and signals through its product, phosphatidic acid [PA]) and another that involves protein-protein interactions. The first is evidenced by partial abrogation of chemotaxis with lipase activity-defective constructs (PLD2-K758R) and by n-butanol treatment of cells. The second is evidenced by PLD association with the growth factor receptor-bound protein 2 (Grb2) through residue Y169, located within a Src homology 2 (SH2) consensus site. The association Grb2-PLD2 could be visualized by fluorescence microscopy in RAW/LR5 macrophages concentrated in actin-rich membrane ruffles, making possible that Grb2 serves as a docking or intermediary protein. The Grb2/PLD2-mediated chemotaxis process also depends on Grb2's ability to recognize other motility proteins, like the Wiskott-Aldrich syndrome protein (WASP). Cell transfection with WASP, PLD2, and Grb2 constructs yields the highest levels of cell migration response, particularly in a macrophage cell line (RAW/LR5) and only modestly in the fibroblast cell line COS-7. Further, RAW/LR5 macrophages utilize for cell migration an additional pathway that involves S6 kinase (S6K) through PLD2-Y296, known to be phosphorylated by epidermal growth factor receptor (EGFR) kinase. Thus, both fibroblasts and macrophages use activity-dependent and activity-independent signaling mechanisms. However, highly mobile cells like macrophages use all signaling machinery available to them to accomplish their required function in rapid immune response, which sets them apart from fibroblasts, cells normally nonmobile that are only briefly involved in wound healing.

THE SUCCESS OF THE LUCERNE MESSAGE IN MARLBOROUGH

1981 ◽  
pp. 179-183
Author(s):  
A.J. Cresswell
Keyword(s):  
North America ◽  
Weed Control ◽  
Seed Yield ◽  
Insect Pest ◽  
Fold Increase ◽  
Plant Spacing ◽  
Insect Pest Control ◽  
One Year ◽  
Seed Yields ◽  
New Cultivars

This paper, as well as being a testimonial to the benefit the writer has received from the Grassland Association, shows how the knowledge of scientists has been used to increase lucerne seed yields by methods of growing resistant cultivars especially for seed production as opposed to growing for hay, silage or grazing. It shows how new cultivars can be multiplied quickly by growing two crops in one year, one in each hemisphere, by using low seeding rates, wide plant spacing and very good weed control. Increased flowering of the crop has been achieved by the use of boron and the choice of time of closing; better pollination has been achieved by the use of more efficient bees - two varieties of which have been imported from North America. Weed and insect pest control and the use of a desiccant at harvest are contributing to a four-fold increase in seed yield, which should double again soon,

scholarly journals Cuticle degrading enzyme production by some isolates of the entomopathogenic fungus, Metarhizium anisopliae (Metsch.)

2014 ◽  
Vol 20 ◽  
pp. 25-32
Author(s):  
N Sapna Bai ◽  
OK Remadevi ◽  
TO Sasidharan ◽  
M Balachander ◽  
Priyadarsanan Dharmarajan
Keyword(s):  
Pest Control ◽  
Entomopathogenic Fungi ◽  
Enzyme Production ◽  
Insect Pest ◽  
Strong Relationship ◽  
Control Agent ◽  
Mechanical Pressure ◽  
Degrading Enzyme ◽  
Insect Pest Control ◽  
Degrading Enzymes

Context: Entomopathogenic fungi have been recognized as viable alternate options to chemicals in insect pest control. Unlike other potential biocontrol agents, fungi do not have to be ingested to infect their hosts but invade directly through the cuticle. Entry into the host involves both enzymic degradation of the cuticle barrier and mechanical pressure. Production of a range of cuticle degrading enzymes is an important event in the interaction of entomopathogenic fungi and host. Enzyme secretion is believed to be a key contributor for the virulence of a fungal isolate. Objectives: The potentiality of nine isolates of M. anisopliae were tested to produce to produce three important cuticle degrading enzymes, viz., chitinase, protease and lipase. Materials and Methods: Nine isolates of M. anisopliae were evaluated for chitinase, protease and lipase enzyme production by determining the enzyme index and activities. Results: Chitinase index of these isolates were ranged from 1.5 to 2.2 and chitinolytic activity from 0.525 to 1.560 U/ml. The isolates showed protease index in the range of 1.2 to 3.3 and the activity ranged from 0.020 to 0.114 U/ml. Lipase index ranged from 1.15 to 7.0 and the enzyme activity ranged from 0.153 to 0.500 U/ml. A strong relationship was observed between virulence of the isolates and cuticle degrading enzyme production as increased enzyme production was observed for virulent isolates. Conclusion: In the present study three isolates as (MIS2, MIS7 and MIS13) demonstrated cuticle degrading enzyme (CDE) that indicate higher virulence based on the bioassay conducted earlier by the authors as strongly substantiating the role of CDEs is considered the virulence of Metarhizium isolates. So, these isolates may be as ecofriendly insect-pest control agent in future. DOI: http://dx.doi.org/10.3329/jbs.v20i0.17648 J. bio-sci. 20: 25-32, 2012

scholarly journals Modulation of the Immune Response by Deferasirox in Myelodysplastic Syndrome Patients

2021 ◽  
Vol 14 (1) ◽  
pp. 41
Author(s):  
Hana Votavova ◽  
Zuzana Urbanova ◽  
David Kundrat ◽  
Michaela Dostalova Merkerova ◽  
Martin Vostry ◽  
...  
Keyword(s):  
Gene Expression ◽  
Immune Response ◽  
Blood Cell ◽  
Myelodysplastic Syndrome ◽  
Molecular Mechanisms ◽  
Expression Profiles ◽  
Adaptive Immune Response ◽  
Gene Expression Profiles ◽  
Iron Chelator ◽  
Multiple Cancer

Deferasirox (DFX) is an oral iron chelator used to reduce iron overload (IO) caused by frequent blood cell transfusions in anemic myelodysplastic syndrome (MDS) patients. To study the molecular mechanisms by which DFX improves outcome in MDS, we analyzed the global gene expression in untreated MDS patients and those who were given DFX treatment. The gene expression profiles of bone marrow CD34+ cells were assessed by whole-genome microarrays. Initially, differentially expressed genes (DEGs) were determined between patients with normal ferritin levels and those with IO to address the effect of excessive iron on cellular pathways. These DEGs were annotated to Gene Ontology terms associated with cell cycle, apoptosis, adaptive immune response and protein folding and were enriched in cancer-related pathways. The deregulation of multiple cancer pathways in iron-overloaded patients suggests that IO is a cofactor favoring the progression of MDS. The DEGs between patients with IO and those treated with DFX were involved predominantly in biological processes related to the immune response and inflammation. These data indicate DFX modulates the immune response mainly via neutrophil-related genes. Suppression of negative regulators of blood cell differentiation essential for cell maturation and upregulation of heme metabolism observed in DFX-treated patients may contribute to the hematopoietic improvement.

scholarly journals Sublethal Exposure Effects of the Neonicotinoid Clothianidin Strongly Modify the Brain Transcriptome and Proteome in the Male Moth Agrotis ipsilon

Insects ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 152
Author(s):  
Camille Meslin ◽  
Françoise Bozzolan ◽  
Virginie Braman ◽  
Solenne Chardonnet ◽  
Cédric Pionneau ◽  
...  
Keyword(s):  
Sex Pheromone ◽  
Molecular Mechanisms ◽  
Insect Pest ◽  
Agrotis Ipsilon ◽  
Positive Effects ◽  
Male Moth ◽  
Hormetic Effect ◽  
Pest Insects ◽  
Neuronal Processes ◽  
The Brain

Insect pest management relies mainly on neurotoxic insecticides, including neonicotinoids such as clothianidin. The residual accumulation of low concentrations of these insecticides can have positive effects on target pest insects by enhancing various life traits. Because pest insects often rely on sex pheromones for reproduction and olfactory synaptic transmission is cholinergic, neonicotinoid residues could indeed modify chemical communication. We recently showed that treatments with low doses of clothianidin could induce hormetic effects on behavioral and neuronal sex pheromone responses in the male moth, Agrotis ipsilon. In this study, we used high-throughput RNAseq and proteomic analyses from brains of A. ipsilon males that were intoxicated with a low dose of clothianidin to investigate the molecular mechanisms leading to the observed hormetic effect. Our results showed that clothianidin induced significant changes in transcript levels and protein quantity in the brain of treated moths: 1229 genes and 49 proteins were differentially expressed upon clothianidin exposure. In particular, our analyses highlighted a regulation in numerous enzymes as a possible detoxification response to the insecticide and also numerous changes in neuronal processes, which could act as a form of acclimatization to the insecticide-contaminated environment, both leading to enhanced neuronal and behavioral responses to sex pheromone.

scholarly journals Anti-Fibrosis Effects of Magnesium Lithospermate B in Experimental Pulmonary Fibrosis: By Inhibiting TGF-βRI/Smad Signaling

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1715
Author(s):  
Xin Luo ◽  
Qiangqiang Deng ◽  
Yaru Xue ◽  
Tianwei Zhang ◽  
Zhitao Wu ◽  
...  
Keyword(s):  
Pulmonary Fibrosis ◽  
Cell Line ◽  
Molecular Mechanisms ◽  
Transforming Growth Factor ◽  
Salvia Miltiorrhiza ◽  
A549 Cells ◽  
Epithelial Cell Line ◽  
Human Lung Fibroblast ◽  
Magnesium Lithospermate B

Pulmonary fibrosis is a severe and irreversible interstitial pulmonary disease with high mortality and few treatments. Magnesium lithospermate B (MLB) is a hydrosoluble component of Salvia miltiorrhiza and has been reported to have antifibrotic effects in other forms of tissue fibrosis. In this research, we studied the effects of MLB on pulmonary fibrosis and the underlying mechanisms. Our results indicated that MLB treatment (50 mg/kg) for seven days could attenuate bleomycin (BLM)-induced pulmonary fibrosis by reducing the alveolar structure disruption and collagen deposition in the C57 mouse model. MLB was also found to inhibit transforming growth factor-beta (TGF-β)-stimulated myofibroblastic transdifferentiation of human lung fibroblast cell line (MRC-5) cells and collagen production by human type II alveolar epithelial cell line (A549) cells, mainly by decreasing the expression of TGF-β receptor I (TGF-βRI) and regulating the TGF-β/Smad pathway. Further studies confirmed that the molecular mechanisms of MLB in BLM-induced pulmonary fibrosis mice were similar to those observed in vitro. In summary, our results demonstrated that MLB could alleviate experimental pulmonary fibrosis both in vivo and in vitro, suggesting that MLB has great potential for pulmonary fibrosis treatment.

scholarly journals TAMI-07. THE IMMUNE MICROENVIRONMENT IN LOWER GRADE GLIOMAS

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii214-ii214
Author(s):  
Anupam Kumar ◽  
Katharine Chen ◽  
Claudia Petritsch ◽  
Theodore Nicolaides ◽  
Mariarita Santi-Vicini ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Cd8 T Cells ◽  
Molecular Mechanisms ◽  
T Regulatory Cells ◽  
Immune Cell ◽  
T Cell Response ◽  
Cytotoxic T Cell ◽  
Lower Grade ◽  
Functional Relationships

Abstract The determinants of the tumor-associated immune response in brain tumors are poorly understood. Using tumor samples from two molecularly distinct subtypes of lower grade glioma, MAPK-driven glioma with biallelic inactivation of CDKN2A (n=30) and IDH-mutant, 1p/19q-intact astrocytoma (n=29), we demonstrate qualitative and quantitative differences in the tumor-associated immune response and we investigate the molecular mechanisms involved. Histologically the MAPK-driven gliomas were comprised of pleomorphic xanthoastrocytoma (PXA) (n=11) and anaplastic PXA (n=19). Seven patients had paired samples from two sequential surgeries. Immune cell populations and their activity were determined by quantitative multiplex immunostaining and Digital Spatial Profiling and gene expression was analyzed by Nanostring. Functional studies were performed using established cell lines and two new patient-derived lines from MAPK-driven LGGs. MAPK-driven tumors exhibited an increased number of CD8+ T cells and tumor-associated microglial/macrophage (TAMs), including CD163+ TAMs, as compared to IDH-mutant astrocytoma. In contrast, IDH-mutant tumors had increased FOXP3+ immunosuppressive T regulatory cells. Transcriptional and protein level analyses in MAPK-driven tumors suggested an active cytotoxic T cell response with robust expression of granzyme B, present on 27% of CD8+ T cells, increased MHC class I expression, and altered cytokine profiles. Interestingly, MAPK-driven tumors also had increased expression of immunosuppressive molecules, including CXCR4, PD-L1, and VEGFA. Expression differences for cell surface and secreted proteins were confirmed in patient-derived tumor lines and functional relationships between altered chemokine expression and immune cell infiltration was investigated. Our data provide novel insights into the immune contexture of MAPK driven LGGs and suggest MAPK driven gliomas with biallelic inactivation of CDKN2A may be particularly vulnerable to immunotherapeutic modulation

scholarly journals Analysis of a Preliminary microRNA Expression Signature in a Human Telangiectatic Osteogenic Sarcoma Cancer Cell Line

2021 ◽  
Vol 22 (3) ◽  
pp. 1163
Author(s):  
Gaia Palmini ◽  
Cecilia Romagnoli ◽  
Simone Donati ◽  
Roberto Zonefrati ◽  
Gianna Galli ◽  
...  
Keyword(s):  
Cell Line ◽  
Molecular Mechanisms ◽  
Osteogenic Sarcoma ◽  
Cancer Cell Line ◽  
Microscopic Features ◽  
In Vitro Establishment ◽  
Profile Characteristic ◽  
First Time

Telangiectatic osteosarcoma (TOS) is an aggressive variant of osteosarcoma (OS) with distinctive radiographic, gross, microscopic features, and prognostic implications. Despite several studies on OS, we are still far from understanding the molecular mechanisms of TOS. In recent years, many studies have demonstrated not only that microRNAs (miRNAs) are involved in OS tumorigenesis, development, and metastasis, but also that the presence in high-grade types of OS of cancer stem cells (CSCs) plays an important role in tumor progression. Despite these findings, nothing has been described previously about the expression of miRNAs and the presence of CSCs in human TOS. Therefore, we have isolated/characterized a putative CSC cell line from human TOS (TOS-CSCs) and evaluated the expression levels of several miRNAs in TOS-CSCs using real-time quantitative assays. We show, for the first time, the existence of CSCs in human TOS, highlighting the in vitro establishment of this unique stabilized cell line and an identification of a preliminary expression of the miRNA profile, characteristic of TOS-CSCs. These findings represent an important step in the study of the biology of one of the most aggressive variants of OS and the role of miRNAs in TOS-CSC behavior.

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