scholarly journals Influenza prevention and treatment by passive immunization.

2014 ◽  
Vol 61 (3) ◽  
Author(s):  
Barbara Kalenik ◽  
Róża Sawicka ◽  
Anna Góra-Sochacka ◽  
Agnieszka Sirko
Keyword(s):  
Neutralizing Antibodies ◽  
Passive Immunization ◽  
Egg Yolk ◽  
Passive Immunity ◽  
Protective Effects ◽  
In Vivo Experiments ◽  
Effective Care ◽  
Antibody Preparations

Passive immunity is defined as a particular antigen resistance provided by external antibodies. It can be either naturally or artificially acquired. Natural passive immunization occurs during pregnancy and breast-feeding in mammals and during hatching in birds. Maternal antibodies are passed through the placenta and milk in mammals and through the egg yolk in birds. Artificial passive immunity is acquired by injection of either serum from immunized (or infected) individuals or antibody preparations. Many independent research groups worked on selection, verification and detailed characterization of polyclonal and monoclonal antibodies against the influenza virus. Numerous antibody preparations were tested in a variety of in vitro and in vivo experiments for their efficacy to neutralize the virus. Here, we describe types of antibodies tested in such experiments and their viral targets, review approaches resulting in identification of broadly neutralizing antibodies and discuss methods used to demonstrate their protective effects. Finally, we shortly discuss the phenomenon of maternal antibody transfer as a way of effective care for young individuals and as an interfering factor in early vaccination.

Passive protection of purified yolk immunoglobulin administered against Shiga toxin 1 in mouse models

2010 ◽  
Vol 56 (12) ◽  
pp. 1003-1010 ◽  
Author(s):  
Qin Wang ◽  
Xiao-jun Hou ◽  
Kun Cai ◽  
Tao Li ◽  
Yue-nan Liu ◽  
...  
Keyword(s):  
Shiga Toxin ◽  
Protective Efficacy ◽  
Wide Spectrum ◽  
Egg Yolk ◽  
Chromatography Method ◽  
In Vivo Experiments ◽  
Enteric Diseases ◽  
Uremic Syndrome

Shiga toxins produced by Escherichia coli O157:H7 cause a wide spectrum of enteric diseases, such as lethal hemorrhagic colitis and hemolytic uremic syndrome. In this study, the B subunit protein of Shiga toxin type 1 (Stx1) was produced in the E. coli system, was further purified by Ni-column Affinity Chromatography method, and was then used as an immunogen to immunize laying hens for yolk immunoglobulin (IgY) production. Titers of IgY increased gradually with boosting vaccination and, finally, reached a level of 105, remaining steady over 1 year. Then the protective efficacy of IgY against Stx1 was evaluated by in vitro and in vivo experiments. It was shown that the anti-Stx1 IgY could effectively block the binding of Stx1 to the Hela cells and could protect BALB/c mice from toxin challenges. The data indicates the facility of using egg yolk IgY as a therapeutic intervention in cases of Shiga toxin intoxication.

scholarly journals Study of the Effects of Total Flavonoids of Astragalus on Atherosclerosis Formation and Potential Mechanisms

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Deqing Wang ◽  
Yuan Zhuang ◽  
Yaping Tian ◽  
Graham Neil Thomas ◽  
Mingzhong Ying ◽  
...  
Keyword(s):  
Cardiovascular Disease ◽  
Ischemia Reperfusion ◽  
Animal Experiments ◽  
Hdl Cholesterol ◽  
Total Flavonoids ◽  
Protective Effects ◽  
In Vivo Experiments ◽  
Cholesterol Levels

Astragalus mongholicusBunge has long been used to treat cardiovascular disease in Chinese traditional medicine. However, its mechanisms are not fully understood. In this study, we explored potential mechanisms and protective effects of total flavonoids of Astragalus (TFA) on cardiovascular disease using in vitro experiments and diet-induced atherosclerotic rabbits. We identified six components and their proportion in TFA. The animal experiments showed that TFA significantly reduced plasma levels of total cholesterol and LDL cholesterol (P<0.05to 0.01), increased HDL cholesterol levels (P<0.01), and reduced the aortic fatty streak area by 43.6 to 63.6% (P<0.01). We also found that TFA scavenged superoxide and hydroxyl radicals and this effect increased with higher TFA concentration. In in vivo experiments, TFA effectively inhibited the free radical spectrum in the ischemia-reperfusion module. In conclusion, TFA was the active component ofAstragalus mongholicusBunge, which benefits cardiovascular disease attributing to the potent antioxidant activity to improve the atherosclerosis profile.

scholarly journals New SHIVs and Improved Design Strategy for Modeling HIV-1 Transmission, Immunopathogenesis, Prevention and Cure

2021 ◽  
Author(s):  
Hui Li ◽  
Shuyi Wang ◽  
Fang-Hua Lee ◽  
Ryan S. Roark ◽  
Alex I. Murphy ◽  
...  
Keyword(s):  
T Cells ◽  
Neutralizing Antibodies ◽  
Large Scale ◽  
Rhesus Macaques ◽  
Passive Immunization ◽  
Design Strategy ◽  
Efficient Replication ◽  
Hiv 1

Previously, we showed that substitution of HIV-1 Env residue 375-Ser by bulky aromatic residues enhances binding to rhesus CD4 and enables primary HIV-1 Envs to support efficient replication as simian-human immunodeficiency virus (SHIV) chimeras in rhesus macaques (RMs). Here, we test this design strategy more broadly by constructing SHIVs containing ten primary Envs corresponding to HIV-1 subtypes A, B, C, AE and AG. All ten SHIVs bearing wildtype Env375 residues replicated efficiently in human CD4+ T cells, but only one replicated efficiently in primary rhesus cells. This was a subtype AE SHIV that naturally contained His at Env375. Replacement of wildtype Env375 residues by Trp, Tyr, Phe or His in the other nine SHIVs led to efficient replication in rhesus CD4+ T cells in vitro and in vivo. Nine SHIVs containing optimized Env375 alleles were grown large-scale in primary rhesus CD4+ T cells to serve as challenge stocks in preclinical prevention trials. These virus stocks were genetically homogeneous, native-like in Env antigenicity and tier-2 neutralization sensitivity, and transmissible by rectal, vaginal, penile, oral or intravenous routes. To facilitate future SHIV constructions, we engineered a simplified second-generation design scheme and validated it in RMs. Overall, our findings demonstrate that SHIVs bearing primary Envs with bulky aromatic substitutions at Env375 consistently replicate in RMs, recapitulating many features of HIV-1 infection in humans. Such SHIVs are efficiently transmitted by mucosal routes common to HIV-1 infection and can be used to test vaccine efficacy in preclinical monkey trials. Importance SHIV infection of Indian rhesus macaques is an important animal model for studying HIV-1 transmission, prevention, immunopathogenesis and cure. Such research is timely, given recent progress with active and passive immunization and novel approaches to HIV-1 cure. Given the multifaceted roles of HIV-1 Env in cell tropism and virus entry, and as a target for neutralizing and non-neutralizing antibodies, Envs selected for SHIV construction are of paramount importance. Until recently, it has been impossible to strategically design SHIVs bearing clinically relevant Envs that replicate consistently in monkeys. This changed with the discovery that bulky aromatic substitutions at residue Env375 confer enhanced affinity to rhesus CD4. Here, we show that 10 new SHIVs bearing primary HIV-1 Envs with residue 375 substitutions replicated efficiently in RMs and could be transmitted efficiently across rectal, vaginal, penile and oral mucosa. These findings suggest an expanded role for SHIVs as a model of HIV-1 infection.

Regulation of physiological and pathological Th1 and Th2 responses by lactoferrinThis paper is one of a selection of papers published in this Special Issue, entitled 7th International Conference on Lactoferrin: Structure, Function, and Applications, and has undergone the Journal's usual peer review process.

2006 ◽  
Vol 84 (3) ◽  
pp. 303-311 ◽  
Author(s):  
Romy Fischer ◽  
Hajer Debbabi ◽  
Michel Dubarry ◽  
Prosper Boyaka ◽  
Daniel Tomé
Keyword(s):  
Inflammatory Responses ◽  
Peer Review Process ◽  
Allergic Diseases ◽  
Protective Effects ◽  
In Vivo Experiments ◽  
Cytokine Balance ◽  
Th1 And Th2 Responses ◽  
Th1 Polarization

In recent years, Lf has gained increasing interest as a result of its protective effects against a variety of diseases. While iron binding and interactions with mammalian receptors and microbial components are the best described mechanisms of action, recent studies have provided evidence that Lf properties may be related to immunoregulatory effects on Th1/Th2 cell activities. In vitro and in vivo experiments show that Lf is able to stimulate the differentiation of T cells from their immature precursors through the induction of the CD4 antigen. Studies performed under nonpathogenic conditions have shown distinct results with regard to the ability of Lf to support the proliferation and differentiation of Th cells into the Th1 or the Th2 phenotype. In addition, Lf plays different roles in diseases by affecting the Th1/Th2 cytokine balance in a manner dependent on the host’s immune status. Thus, Lf could cause a Th1 polarization in diseases in which the ability to control infection or tumor relies on a strong Th1 response. Lf may also reduce the Th1 component to limit excessive inflammatory responses. Finally, Lf may provide protection against Th1- or Th2-induced diseases, such as autoimmune or allergic diseases, through correction of the Th1/Th2 imbalance.

scholarly journals Human neutralizing antibodies for SARS-CoV-2 prevention and immunotherapy

2021 ◽  
Author(s):  
Dongyan Zhou ◽  
Runhong Zhou ◽  
Zhiwei Chen
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Neutralizing Antibodies ◽  
Immune Escape ◽  
Passive Immunization ◽  
Clinical Development ◽  
Vaccine Research ◽  
Breakthrough Infection ◽  
Clinical Benefits

Abstract Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of coronavirus disease 2019 (COVID-19). SARS-CoV-2 has been spreading worldwide since December 2019, resulting in the ongoing COVID-19 pandemic with 237 million infections and 4.8 million deaths by 11 October 2021. While there are great efforts of global vaccination, ending this pandemic has been challenged by issues of exceptionally high viral transmissibility, re-infection, vaccine-breakthrough infection, and immune escape variants of concerns. Besides the record-breaking speed of vaccine research and development, antiviral drugs including SARS-CoV-2-specific human neutralizing antibodies (HuNAbs) have been actively explored for passive immunization. In support of HuNAb-based immunotherapy, passive immunization using convalescent patients’ plasma have generated promising evidence on clinical benefits for both mild and severe COVID-19 patients. Since the source of convalescent plasma is limited, the discovery of broadly reactive HuNAbs may have significant impacts on the fight against the COVID-19 pandemic. In this review, therefore, we discuss the current technologies of gene cloning, modes of action, in vitro and in vivo potency and breadth, and clinical development for potent SARS-CoV-2-specific HuNAbs.

scholarly journals Isoflurane Preconditioning Promotes the Survival and Migration of Bone Marrow Stromal Cells

2015 ◽  
Vol 36 (4) ◽  
pp. 1331-1345 ◽  
Author(s):  
Yu Sun ◽  
Qi-fang Li ◽  
Jia Yan ◽  
Rong Hu ◽  
Hong Jiang
Keyword(s):  
Bone Marrow ◽  
Hypoxia Inducible Factor ◽  
Volatile Anesthetic ◽  
Protective Effects ◽  
In Vivo Experiments ◽  
High Doses ◽  
And Migration ◽  
And Function

Background: Preconditioning with the volatile anesthetic isoflurane exerts protective effects in animal models of ischemia. The cytoprotective effects of isoflurane are dependent on the expression of hypoxia inducible factor-1 (HIF-1), a dimeric transcription factor that mediates cellular responses to hypoxia. Methods: We investigated the effect of isoflurane preconditioning on bone marrow stromal cell (BMSC) survival and function. Results: Short exposures to low isoflurane concentrations promoted in vitro survival and migration of BMSCs, whereas long exposures and high doses had the opposite effect. At specific doses and times, isoflurane upregulated the expression of HIF-1α and the stromal-derived factor-1 receptor CXCR4, and induced the activation of Akt, similar to hypoxia, and the effect of isoflurane was abrogated by silencing of HIF-1α or inhibition of PI3K/Akt signaling. In vivo experiments showed that isoflurane preconditioning increased the engraftment of BMSCs into the ischemic brain and improved functional recovery in a mouse model of stroke. Conclusion: Isoflurane preconditioning at specific doses and times improves the survival and function of BMSCs through the upregulation of CXCR4 via a mechanism involving HIF-1α expression and the PI3K/Akt pathway, suggesting that anesthetic preconditioning could be developed as a strategy to improve the efficiency of cell therapy.

scholarly journals Involvement of UTP in protection of cardiomyocytes from hypoxic stressThis article is one of a selection of papers from the NATO Advanced Research Workshop on Translational Knowledge for Heart Health (published in part 2 of a 2-part Special Issue).

2009 ◽  
Vol 87 (4) ◽  
pp. 287-299 ◽  
Author(s):  
Asher Shainberg ◽  
Smadar Yitzhaki ◽  
Or Golan ◽  
Kenneth A. Jacobson ◽  
Edith Hochhauser
Keyword(s):  
Infarct Size ◽  
Cardiovascular System ◽  
Receptor Activation ◽  
Mitochondrial Activity ◽  
Mitochondrial Calcium ◽  
Protective Effects ◽  
In Vivo Experiments ◽  
Pyrimidine Nucleotide

Massive amounts of nucleotides are released during ischemia in the cardiovascular system. Although the effect of the purine nucleotide ATP has been intensively studied in myocardial infarction, the cardioprotective role of the pyrimidine nucleotide UTP is still unclear, especially in the cardiovascular system. The purpose of our study was to elucidate the protective effects of UTP receptor activation and describe the downstream cascade for the cardioprotective effect. Cultured cardiomyocytes and left anterior descending (LAD)-ligated rat hearts were pretreated with UTP and exposed to hypoxia–ischemia. In vitro experiments revealed that UTP reduced cardiomyocyte death induced by hypoxia, an effect that was diminished by suramin. UTP caused several effects that could trigger a cardioprotective response: a transient increase of [Ca2+]i, an effect that was abolished by PPADS or RB2; phosphorylation of the kinases ERK and Akt, which was abolished by U0126 and LY294002, respectively; and reduced mitochondrial calcium elevation after hypoxia. In vivo experiments revealed that UTP maintained ATP levels, improved mitochondrial activity, and reduced infarct size. In conclusion, UTP administrated before ischemia reduced infarct size and improved myocardial function. Reduction of mitochondrial calcium overload can partially explain the protective effect of UTP after hypoxic–ischemic injury.

scholarly journals In Vivo and In Vitro Escape from Neutralizing Antibodies 2G12, 2F5, and 4E10

2007 ◽  
Vol 81 (16) ◽  
pp. 8793-8808 ◽  
Author(s):  
Amapola Manrique ◽  
Peter Rusert ◽  
Beda Joos ◽  
Marek Fischer ◽  
Herbert Kuster ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
In Vitro Selection ◽  
Passive Immunization ◽  
Resistance Mutations ◽  
Antibody Treatment ◽  
Glycosylation Sites ◽  
Depth Analysis ◽  
Immunodeficiency Virus

ABSTRACT Recently, passive immunization of human immunodeficiency virus (HIV)-infected individuals with monoclonal antibodies (MAbs) 2G12, 2F5, and 4E10 provided evidence of the in vivo activity of 2G12 but raised concerns about the function of the two membrane-proximal external region (MPER)-specific MAbs (A. Trkola, H. Kuster, P. Rusert, B. Joos, M. Fischer, C. Leemann, A. Manrique, M. Huber, M. Rehr, A. Oxenius, R. Weber, G. Stiegler, B. Vcelar, H. Katinger, L. Aceto, and H. F. Gunthard, Nat. Med. 11:615-622, 2005). In the light of MPER-targeting vaccines under development, we performed an in-depth analysis of the emergence of mutations conferring resistance to these three MAbs to further elucidate their activity. Clonal analysis of the MPER of plasma virus samples derived during antibody treatment confirmed that no changes in this region had occurred in vivo. Sequence analysis of the 2G12 epitope relevant N-glycosylation sites of viruses derived from 13 patients during the trial supported the phenotypic evaluation, demonstrating that mutations in these sites are associated with resistance. In vitro selection experiments with isolates of four of these individuals corroborated the in vivo finding that virus strains rapidly escape 2G12 pressure. Notably, in vitro resistance mutations differed, in most cases, from those found in vivo. Importantly, in vitro selection with 2F5 and 4E10 demonstrated that resistance to these MAbs can be difficult to achieve and can lead to selection of variants with impaired infectivity. This remarkable vulnerability of the virus to interference within the MPER calls for a further evaluation of the safety and efficacy of MPER-targeting therapeutic and vaccination strategies.

scholarly journals Protective Effects of STI-2020 Antibody Delivered Post-Infection by the Intranasal or Intravenous Route in a Syrian Golden Hamster COVID-19 Model

2020 ◽  
Author(s):  
Yanwen Fu ◽  
Junki Maruyama ◽  
Alok Singh ◽  
Reyna Lim ◽  
Arthur Ledesma ◽  
...  
Keyword(s):  
Lung Tissue ◽  
Post Infection ◽  
Neutralizing Antibodies ◽  
In Vivo Studies ◽  
Intravenous Route ◽  
Protective Effects ◽  
Antibody Treatment ◽  
Hamster Model

ABSTRACTWe have previously reported that the SARS-CoV-2 neutralizing antibody, STI-2020, potently inhibits cytopathic effects of infection by genetically diverse clinical SARS-CoV-2 pandemic isolates in vitro, and has demonstrated efficacy in a hamster model of COVID-19 when administered by the intravenous route immediately following infection. We now have extended our in vivo studies of STI-2020 to include disease treatment efficacy, profiling of biodistribution of STI-2020 in mice when antibody is delivered intranasally (IN) or intravenously (IV), as well as pharmacokinetics in mice following IN antibody administration. Importantly, SARS-CoV-2-infected hamsters were treated with STI-2020 using these routes, and treatment effects on severity and duration of COVID-19-like disease in this model were evaluated. In SARS-CoV-2 infected hamsters, treatment with STI-2020 12 hours post-infection using the IN route led to a decrease in severity of clinical disease signs and a more robust recovery during 9 days of infection as compared to animals treated with an isotype control antibody. Treatment via the IV route using the same dose and timing regimen resulted in a decrease in the average number of consecutive days that infected animals experienced weight loss, shortening the duration of disease and allowing recovery to begin more rapidly in STI-2020 treated animals. Following IN administration in mice, STI-2020 was detected within 10 minutes in both lung tissue and lung lavage. The half-life of STI-2020 in lung tissue is approximately 25 hours. We are currently investigating the minimum effective dose of IN-delivered STI-2020 in the hamster model as well as establishing the relative benefit of delivering neutralizing antibodies by both IV and IN routes.

scholarly journals Refrigeration of eggs influences the virulence of Salmonella Typhimurium

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Samiullah Khan ◽  
Andrea R. McWhorter ◽  
Talia S. Moyle ◽  
Kapil K. Chousalkar
Keyword(s):  
Bacterial Load ◽  
Egg Yolk ◽  
The United States ◽  
In Vivo Experiments ◽  
Genes Expression ◽  
Egg Storage ◽  
Storage Temperatures

AbstractSalmonella Typhimurium is a human pathogen associated with eggs and egg-derived products. In Australia, it is recommended that eggs should be refrigerated to prevent condensation that can enhance bacterial penetration across the eggshell. Except for the United States, the guidelines on egg refrigeration are not prescriptive. In the current study, in-vitro and in-vivo experiments were conducted to understand the role of egg storage temperatures (refrigerated vs ambient) on bacterial load and the virulence genes expression of Salmonella Typhimurium. The in-vitro egg study showed that the load of Salmonella Typhimurium significantly increased in yolk and albumen stored at 25 °C. The gene expression study showed that ompR, misL, pefA, spvA, shdA, bapA, and csgB were significantly up-regulated in the egg yolk stored at 5 °C and 25 °C for 96 h; however, an in-vivo study revealed that mice infected with egg yolk stored at 25 °C, developed salmonellosis from day 3 post-infection (p.i.). Mice fed with inoculated egg yolk, albumen, or eggshell wash stored at refrigerated temperature did not show signs of salmonellosis during the period of the experiment. Data obtained in this study highlighted the importance of egg refrigeration in terms of improving product safety.

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