scholarly journals An extensive computational approach to inhibit MSP-1 of P.vivax elucidates further horizon in the establishment next generation therapeutics against malaria

2020 ◽  
Author(s):  
Md Ohedul Islam ◽  
Parag Palit ◽  
Jakaria Shawon ◽  
Md Kamrul Hasan ◽  
Mustafa Mahfuz ◽  
...  
Keyword(s):  
In Silico ◽  
Laboratory Experiments ◽  
Artemisinin Resistance ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Next Generation ◽  
Docking Analysis ◽  
Life Threatening

AbstractMalaria represents a life-threatening disease caused by the obligate intra-erythrocytic protozoa of the Plasmodium genus, exerting a sinister global health burden and accounting for approximately 660,000 deaths annually. Additionally, 219 million new cases are reported each year, most of which result from the growing issue of artemisinin resistance shown by the Plasmodium parasite. Much of the research done for the purpose of development of therapeutics against malaria has traditionally been focused on Plasmodium falciparum, which is responsible for majority of the cases of mortality due to malaria, Plasmodium vivax is also known to contribute greatly towards the malaria relate morbidities particularly in vivax endemic areas. In this study, we have used two different computational approaches aimed at establishing newer concepts towards the development of advanced therapeutics against vivax malaria by targeting the surface antigen, merozoite surface protein-1 (MSP-1). In-silico approach involving computational siRNA designing against MSP-1 resulted in a total of four candidate siRNAs being rationally validated following corroboration with a plethora of algorithms. Additionally, molecular docking analysis unraveled a total of three anti-parasitic peptides. These peptides namely: AP02283, AP02285 and AP00101 were found to exhibit considerable binding affinity with MSP-1 of P.vivax, thus providing an apparent indication of their anti-malarial property and affirming their potency to be used as novel molecules for development of next generation anti-malarials. However, irrespective of the prospective magnitude of these in-silico findings, the results require extensive validation by further rigorous laboratory experiments involving both in-vitro and in-vivo approaches.

Novel antimalarial antibodies highlight the importance of the antibody Fc region in mediating protection

Blood ◽  
2003 ◽  
Vol 102 (13) ◽  
pp. 4424-4430 ◽  
Author(s):  
Richard J. Pleass ◽  
Solabomi A. Ogun ◽  
David H. McGuinness ◽  
Jan G. J. van de Winkel ◽  
Anthony A. Holder ◽  
...  
Keyword(s):  
Passive Immunization ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Plasmodium Yoelii ◽  
Single Chain ◽  
Parasite Drug Resistance ◽  
Parasite Challenge ◽  
Major Target

Abstract Parasite drug resistance and difficulties in developing effective vaccines have precipitated the search for alternative therapies for malaria. The success of passive immunization suggests that immunoglobulin (Ig)-based therapies are effective. To further explore the mechanism(s) by which antibody mediates its protective effect, we generated human chimeric IgG1 and IgA1 and a single-chain diabody specific for the C-terminal 19-kDa region of Plasmodium yoelii merozoite surface protein 1 (MSP119), a major target of protective immune responses. These novel human reagents triggered in vitro phagocytosis of merozoites but, unlike their parental mouse IgG2b, failed to protect against parasite challenge in vivo. Therefore, the Fc region appears critical for mediating protection in vivo, at least for this MSP119 epitope. Such antibodies may serve as prototype therapeutic agents, and as useful tools in the development of in vitro neutralization assays with Plasmodium parasites. (Blood. 2003;102:4424-4430)

scholarly journals Dual mechanisms of opioid-induced respiratory depression in the inspiratory rhythm-generating network

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Nathan A Baertsch ◽  
Nicholas E Bush ◽  
Nicholas J Burgraff ◽  
Jan-Marino Ramirez
Keyword(s):  
Transgenic Mice ◽  
Synaptic Transmission ◽  
Respiratory Depression ◽  
Opioid Receptor ◽  
In Silico ◽  
Pronounced Decrease ◽  
Life Threatening ◽  
Μ Opioid Receptor

The analgesic utility of opioid-based drugs is limited by the life-threatening risk of respiratory depression. Opioid-induced respiratory depression (OIRD), mediated by the μ-opioid receptor (MOR), is characterized by a pronounced decrease in the frequency and regularity of the inspiratory rhythm, which originates from the medullary preBӧtzinger Complex (preBӧtC). To unravel the cellular- and network-level consequences of MOR activation in the preBӧtC, MOR- expressing neurons were optogenetically identified and manipulated in transgenic mice in vitro and in vivo. Based on these results, a model of OIRD was developed in silico. We conclude that hyperpolarization of MOR-expressing preBӧtC neurons alone does not phenocopy OIRD. Instead, the effects of MOR activation are twofold: 1) pre-inspiratory spiking is reduced and 2) excitatory synaptic transmission is suppressed, thereby disrupting network-driven rhythmogenesis. These dual mechanisms of opioid action act synergistically to make the normally robust inspiratory rhythm generating network particularly prone to collapse when challenged with exogenous opioids.

scholarly journals Dual mechanisms of opioid-induced respiratory depression in the inspiratory rhythm-generating network

2021 ◽  
Author(s):  
Nathan A Baertsch ◽  
Nicholas E Bush ◽  
Nicholas J Burgraff ◽  
Jan-Marino Ramirez
Keyword(s):  
Transgenic Mice ◽  
Synaptic Transmission ◽  
Respiratory Depression ◽  
Opioid Receptor ◽  
In Silico ◽  
Pronounced Decrease ◽  
Life Threatening ◽  
Μ Opioid Receptor

AbstractThe analgesic utility of opioid-based drugs is limited by the life-threatening risk of respiratory depression. Opioid-induced respiratory depression (OIRD), mediated by the μ-opioid receptor (MOR), is characterized by a pronounced decrease in the frequency and regularity of the inspiratory rhythm, which originates from the medullary preBötzinger Complex (preBӧtC). To unravel the cellular- and network-level consequences of MOR activation in the preBötC, MOR-expressing neurons were optogenetically identified and manipulated in transgenic mice in vitro and in vivo. Based on these results, a model of OIRD was developed in silico. We conclude that hyperpolarization of MOR-expressing preBötC neurons alone does not phenocopy OIRD. Instead, the effects of MOR activation are twofold: 1) pre-inspiratory spiking is reduced and 2) excitatory synaptic transmission is suppressed, thereby disrupting network-driven rhythmogenesis. These dual mechanisms of opioid action act together to make the normally robust inspiratory-rhythm-generating network particularly prone to collapse when challenged with exogenous opioids.

In vitro and in vivo activities of imipenem combined with BLI-489 against class D β-lactamase-producing Acinetobacter baumannii

2020 ◽  
Author(s):  
Yung-Chih Wang ◽  
Shu-Wei Huang ◽  
Ming-Hsien Chiang ◽  
I-Ming Lee ◽  
Shu-Chen Kuo ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
In Silico ◽  
Active Sites ◽  
Synergistic Effects ◽  
Docking Analysis ◽  
In Silico Docking ◽  
Class D ◽  
Time Kill

Abstract Background According to our preliminary study, BLI-489 has the potential to inhibit the hydrolysing activity of OXA-51-like β-lactamase produced by carbapenem-resistant Acinetobacter baumannii (CRAb). Objectives In the present study, the in vitro and in vivo activities of imipenem combined with BLI-489 against CRAb producing carbapenem-hydrolysing class D β-lactamases (CHDLs), namely OXA-23, OXA-24, OXA-51 and OXA-58, were determined. Methods A chequerboard analysis of imipenem and BLI-489 was performed using 57 and 7 clinical CRAb isolates producing different CHDLs and MBLs, respectively. Four representative strains harbouring different CHDL genes were subjected to a time–kill assay to evaluate the synergistic effects. An in silico docking analysis was conducted to simulate the interactions between BLI-489 and the different families of CHDLs. The in vivo activities of this combination were assessed using a Caenorhabditis elegans survival assay and a mouse pneumonia model. Results Chequerboard analysis showed that imipenem and BLI-489 had a synergistic effect on 14.3, 92.9, 100, 16.7 and 100% of MBL-, OXA-23-, OXA-24-like-, OXA-51-like- and OXA-58-producing CRAb isolates, respectively. In the time–kill assay, imipenem and BLI-489 showed synergy against OXA-24-like-, OXA-51-like- and OXA-58-, but not OXA-23-producing CRAb isolates after 24 h. The in silico docking analysis showed that BLI-489 could bind to the active sites of OXA-24 and OXA-58 to confer strong inhibition activity. The combination of imipenem and BLI-489 exhibited synergistic effects for the rescue of CRAb-infected C. elegans and mice. Conclusions Imipenem combined with BLI-489 has synergistic effects against CHDL-producing CRAb isolates.

scholarly journals Biochemical and Immunological Characterization of Bacterially Expressed and Refolded Plasmodium falciparum 42-Kilodalton C-Terminal Merozoite Surface Protein 1

2003 ◽  
Vol 71 (12) ◽  
pp. 6766-6774 ◽  
Author(s):  
Sanjay Singh ◽  
Michael C. Kennedy ◽  
Carole A. Long ◽  
Allan J. Saul ◽  
Louis H. Miller ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Native Form ◽  
Immunological Characterization ◽  
E Coli ◽  
Merozoite Surface Protein 1 ◽  
Vaccine Trials

ABSTRACT Protection against Plasmodium falciparum can be induced by vaccination in animal models with merozoite surface protein 1 (MSP1), which makes this protein an attractive vaccine candidate for malaria. In an attempt to produce a product that is easily scaleable and inexpensive, we expressed the C-terminal 42 kDa of MSP1 (MSP142) in Escherichia coli, refolded the protein to its native form from insoluble inclusion bodies, and tested its ability to elicit antibodies with in vitro and in vivo activities. Biochemical, biophysical, and immunological characterization confirmed that refolded E. coli MSP142 was homogeneous and highly immunogenic. In a formulation suitable for human use, rabbit antibodies were raised against refolded E. coli MSP142 and tested in vitro in a P. falciparum growth invasion assay. The antibodies inhibited the growth of parasites expressing either homologous or heterologous forms of P. falciparum MSP142. However, the inhibitory activity was primarily a consequence of antibodies directed against the C- terminal 19 kDa of MSP1 (MSP119). Vaccination of nonhuman primates with E. coli MSP142 in Freund's adjuvant protected six of seven Aotus monkeys from virulent infection with P. falciparum. The protection correlated with antibody-dependent mechanisms. Thus, this new construct, E. coli MSP142, is a viable candidate for human vaccine trials.

scholarly journals Comparative Molecular Docking Analysis of Phytoconstituents against Alzheimer’s Disease Targets- An In-Silico Approach

2021 ◽  
Vol 12 (2) ◽  
pp. 1579-1589
Author(s):  
Geethanjali T ◽  
Logesh Kumar S ◽  
Keerthish Sujan B ◽  
Lakshmi Prabhaa M ◽  
Khousikan K ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Alzheimer Disease ◽  
Medicinal Plants ◽  
Panax Ginseng ◽  
In Silico ◽  
Docking Analysis ◽  
In Silico Docking

Alzheimer's disease (AD) is the most common form of dementia and one of the leading causes of death. The Aim and objective of the present study is to perform in-silico docking analysis of the major active constituents identified in three Indian medicinal plants namely Convolvulus pluricaulis, Coriandrum sativum and Panax ginseng for its effectiveness against the targets of Alzheimer Disease. In-silico docking analysis was performed by Molegro Virtual Docker (MVD-2010, 4.2.0) and Schrodinger Mestro (V 11.8). In addition, Drug likeness property, pharmacokinetics (ADME) and safety profile prediction studies were performed to identify the best drug candidates using Qikpro and Toxicity Estimation Software Tool (T.E.S.T). The target for Alzheimer Disease is Acetylcholinesterase and Butyrylcholinesterase. The X-ray crystal co-ordinates of AChE (PDB ID: 4bdt) and BChE (PDB ID: 6eqq) obtained from the Protein Data Bank. The phytoconstituents of three medicinal plants were retrieved from PubChem compound database in mol format. The standard drugs Donepezil, Rivastigmine, Galantamine, Memantine was obtained from the drug bank in .mol format for comparison. It was analysed from the parameters of docking that the phytoconstituents from Panax ginseng showed better anti-Alzheimer activity compared to that of the standard drugs. Based on the research findings, further studies can be performed in in-vitro & in-vivo animal models of Alzheimer’s disease to establish the efficacy of promising phytoconstituents.

scholarly journals Efficacy of Two Alternate Vaccines Based on Plasmodium falciparum Merozoite Surface Protein 1 in anAotus Challenge Trial

2001 ◽  
Vol 69 (3) ◽  
pp. 1536-1546 ◽  
Author(s):  
Anthony W. Stowers ◽  
Vittoria Cioce ◽  
Richard L. Shimp ◽  
Mark Lawson ◽  
George Hui ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Vaccine Antigen ◽  
Merozoite Surface Protein 1 ◽  
Adjuvant Vaccine ◽  
New Formulation ◽  
Antibody Levels

ABSTRACT In an attempt to produce a more defined, clinical-grade version of a vaccine based on Plasmodium falciparum merozoite surface protein 1 (MSP1), we evaluated the efficacy of two recombinant forms of MSP1 in an Aotus nancymai challenge model system. One recombinant vaccine, bvMSP142, based on the 42-kDa C-terminal portion of MSP1, was expressed as a secreted protein in baculovirus-infected insect cells. A highly pure baculovirus product could be reproducibly expressed and purified at yields in excess of 8 mg of pure protein per liter of culture. This protein, when tested for efficacy in the Aotus challenge model, gave significant protection, with only one of seven monkeys requiring treatment for uncontrolled parasitemia after challenge with P. falciparum. The second recombinant protein, P30P2MSP119, has been used in previous studies and is based on the smaller, C-terminal 19-kDa portion of MSP1 expressed inSaccharomyces cerevisiae. Substantial changes were made in its production process to optimize expression. The optimum form of this vaccine antigen (as judged by in vitro and in vivo indicators) was then evaluated, along with bvMSP142, for efficacy in theA. nancymai system. The new formulation of P30P3MSP119 performed significantly worse than bvMSP142 and appeared to be less efficacious than we have found in the past, with four of seven monkeys in the vaccinated group requiring treatment for uncontrolled parasitemia. With both antigens, protection was seen only when high antibody levels were obtained by formulation of the vaccines in Freund's adjuvant. Vaccine formulation in an alternate adjuvant, MF59, resulted in significantly lower antibody titers and no protection.

scholarly journals Quantification of Plasmodium falciparum malaria from complex infections in the Peruvian Amazon using quantitative PCR of the merozoite surface protein 1, block 2 (PfMSP1-B2): in vitro dynamics reveal density-dependent interactions

Parasitology ◽  
2012 ◽  
Vol 139 (6) ◽  
pp. 701-708 ◽  
Author(s):  
THOMAS M. ZERVOS ◽  
JEAN N. HERNANDEZ ◽  
PATRICK L. SUTTON ◽  
ORALEE H. BRANCH
Keyword(s):  
Plasmodium Falciparum ◽  
Quantitative Pcr ◽  
Surface Protein ◽  
Plasmodium Falciparum Malaria ◽  
Merozoite Surface Protein ◽  
Peruvian Amazon ◽  
Field Isolates ◽  
Merozoite Surface Protein 1

SUMMARYThe majority of Plasmodium falciparum field isolates are defined as complex infections because they contain multiple genetically distinct clones. Studying interactions between clones in complex infections in vivo and in vitro could elucidate important phenomena in malaria infection, transmission and treatment. Using quantitative PCR (qPCR) of the P. falciparum merozoite surface protein 1, block 2 (PfMSP1-B2), we provide a sensitive and efficient genotyping method. This is important for epidemiological studies because it makes it possible to study genotype-specific growth dynamics. We compared 3 PfMSP1-B2 genotyping methods by analysing 79 field isolates from the Peruvian Amazon. In vivo observations from other studies using these techniques led to the hypothesis that clones within complex infections interact. By co-culturing clones with different PfMSP1-B2 genotypes, and measuring parasitaemia using qPCR, we found that suppression of clonal expansion was a factor of the collective density of all clones present in a culture. PfMSP1-B2 qPCR enabled us to find in vitro evidence for parasite-parasite interactions and could facilitate future investigations of growth trends in naturally occurring complex infections.

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