In vitro and in vivo preclinical studies predict REGEN-COV protection against emergence of viral escape in humans

SummaryMonoclonal antibodies against SARS-CoV-2 are a clinically validated therapeutic option against COVID-19. As rapidly emerging virus mutants are becoming the next major concern in the fight against the global pandemic, it is imperative that these therapeutic treatments provide coverage against circulating variants and do not contribute to development of treatment emergent resistance. To this end, we investigated the sequence diversity of the spike protein and monitored emergence of minor virus variants in SARS-COV-2 isolates found in nature or identified from preclinical in vitro and in vivo studies and in the clinic. This study demonstrates that a combination of noncompeting antibodies not only provides full coverage against currently circulating variants but also protects against emergence of new such variants and their potential seeding into the population in a clinical setting.

Download Full-text

Possible Future Monoclonal Antibody (mAb)-Based Therapy against Arbovirus Infections

BioMed Research International ◽

10.1155/2013/838491 ◽

2013 ◽

Vol 2013 ◽

pp. 1-21 ◽

Cited By ~ 12

Author(s):

Giuseppe Sautto ◽

Nicasio Mancini ◽

Giacomo Gorini ◽

Massimo Clementi ◽

Roberto Burioni

Keyword(s):

Monoclonal Antibody ◽

Monoclonal Antibodies ◽

Side Effects ◽

Antiviral Activity ◽

The Other ◽

Viral Escape ◽

Passive Immunotherapy ◽

Medical Need

More than 150 arboviruses belonging to different families are known to infect humans, causing endemic infections as well as epidemic outbreaks. Effective vaccines to limit the occurrence of some of these infections have been licensed, while for the others several new immunogens are under development mostly for their improvements concerning safety and effectiveness profiles. On the other hand, specific and effective antiviral drugs are not yet available, posing an urgent medical need in particular for emergency cases. Neutralizing monoclonal antibodies (mAbs) have been demonstrated to be effective in the treatment of several infectious diseases as well as in preliminaryin vitroandin vivomodels of arbovirus-related infections. Given their specific antiviral activity as well-tolerated molecules with limited side effects, mAbs could represent a new therapeutic approach for the development of an effective treatment, as well as useful tools in the study of the host-virus interplay and in the development of more effective immunogens. However, before their use as candidate therapeutics, possible hurdles (e.g., Ab-dependent enhancement of infection, occurrence of viral escape variants) must be carefully evaluated. In this review are described the main arboviruses infecting humans and candidate mAbs to be possibly used in a future passive immunotherapy.

Download Full-text

N-Cadherin Upregulation Promotes the Neurogenic Differentiation of Menstrual Blood-Derived Endometrial Stem Cells

Stem Cells International ◽

10.1155/2018/3250379 ◽

2018 ◽

Vol 2018 ◽

pp. 1-10 ◽

Cited By ~ 1

Author(s):

Yanli Liu ◽

Fen Yang ◽

Shengying Liang ◽

Qing Liu ◽

Sulei Fu ◽

...

Keyword(s):

Stem Cells ◽

Peripheral Nerve ◽

Therapeutic Option ◽

In Vivo Studies ◽

Menstrual Blood ◽

Neurogenic Differentiation ◽

Endometrial Stem Cells ◽

Medical Disorders

Peripheral nerve injuries are typically caused by either trauma or medical disorders, and recently, stem cell-based therapies have provided a promising treatment approach. Menstrual blood-derived endometrial stem cells (MenSCs) are considered an ideal therapeutic option for peripheral nerve repair due to a noninvasive collection procedure and their high proliferation rate and immunological tolerance. Here, we successfully isolated MenSCs and examined their biological characteristics including their morphology, multipotency, and immunophenotype. Subsequent in vitro studies demonstrated that MenSCs express high levels of neurotrophic factors, such as NT3, NT4, BDNF, and NGF, and are capable of transdifferentiating into glial-like cells under conventional induction conditions. Moreover, upregulation of N-cadherin (N-cad) mRNA and protein expression was observed after neurogenic differentiation. In vivo studies clearly showed that N-cad knockdown via in utero electroporation perturbed the migration and maturation of mouse neural precursor cells (NPCs). Finally, a further transfection assay also confirmed that N-cad upregulation in MenSCs results in the expression of S100. Collectively, our results confirmed the paracrine effect of MenSCs on neuroprotection as well as their potential for transdifferentiation into glial-like cells and demonstrated that N-cad upregulation promotes the neurogenic differentiation of MenSCs, thereby providing support for transgenic MenSC-based therapy for peripheral nerve injury.

Download Full-text

Immunogenicity of Recombinant Fiber-Chimeric Adenovirus Serotype 35 Vector-Based Vaccines in Mice and Rhesus Monkeys

Journal of Virology ◽

10.1128/jvi.79.22.14161-14168.2005 ◽

2005 ◽

Vol 79 (22) ◽

pp. 14161-14168 ◽

Cited By ~ 72

Author(s):

Anjali Nanda ◽

Diana M. Lynch ◽

Jaap Goudsmit ◽

Angelique A. C. Lemckert ◽

Bonnie A. Ewald ◽

...

Keyword(s):

Rhesus Monkeys ◽

In Vivo Studies ◽

Preclinical Studies ◽

Adenovirus Serotype ◽

Immunodeficiency Virus ◽

Serotype 5 ◽

Fiber Proteins ◽

Hiv 1

ABSTRACT Preexisting immunity to adenovirus serotype 5 (Ad5) has been shown to suppress the immunogenicity of recombinant Ad5 (rAd5) vector-based vaccines for human immunodeficiency virus type 1 (HIV-1) in both preclinical studies and clinical trials. A potential solution to this problem is to utilize rAd vectors derived from rare Ad serotypes, such as Ad35. However, rAd35 vectors have appeared less immunogenic than rAd5 vectors in preclinical studies to date. In this study, we explore the hypothesis that the differences in immunogenicity between rAd5 and rAd35 vectors may be due in part to differences between the fiber proteins of these viruses. We constructed capsid chimeric rAd35 vectors containing the Ad5 fiber knob (rAd35k5) and compared the immunogenicities of rAd5, rAd35k5, and rAd35 vectors expressing simian immunodeficiency virus Gag and HIV-1 Env in mice and rhesus monkeys. In vitro studies demonstrated that rAd35k5 vectors utilized the Ad5 receptor CAR rather than the Ad35 receptor CD46. In vivo studies showed that rAd35k5 vectors were more immunogenic than rAd35 vectors in both mice and rhesus monkeys. These data suggest that the Ad5 fiber knob contributes substantially to the immunogenicity of rAd vectors. Moreover, these studies demonstrate that capsid chimeric rAd vectors can be constructed to combine beneficial immunologic and serologic properties of different Ad serotypes.

Download Full-text

Hypersensitivity Reactions to Monoclonal Antibodies in Children

Medicina ◽

10.3390/medicina56050232 ◽

2020 ◽

Vol 56 (5) ◽

pp. 232

Author(s):

Francesca Mori ◽

Francesca Saretta ◽

Annamaria Bianchi ◽

Giuseppe Crisafulli ◽

Silvia Caimmi ◽

...

Keyword(s):

Monoclonal Antibodies ◽

Therapeutic Option ◽

Provocation Test ◽

Type I ◽

Hypersensitivity Reactions ◽

Biologic Drugs ◽

Type Iv ◽

Drug Provocation Test

Biologic drugs are widely used in pediatric medicine. Monoclonal antibodies (mAbs) in particular are a therapeutic option for rheumatic, autoinflammatory and oncologic diseases. Adverse drug reactions and hypersensitivity reactions (HSR) to mAbs may occur in children. Clinical presentation of HSRs to mAbs can be classified according to phenotypes in infusion-related reactions, cytokine release syndrome, both alpha type reactions and type I (IgE/non-IgE), type III, and type IV reactions, all beta-type reactions. The aim of this review is to focus on HSRs associated with the most frequent mAbs in childhood, with particular attention to beta-type reactions. When a reaction to mAbs is suspected a diagnostic work-up including in-vivo and in-vitro testing should be performed. A drug provocation test is recommended only when no alternative drugs are available. In selected patients with immediate IgE-mediated drug allergy a desensitization protocol is indicated. Despite the heavy use of mAbs in childhood, studies evaluating the reliability of diagnostic test are lacking. Although desensitization may be effective in reducing the risk of reactions in children, standardized pediatric protocols are still not available.

Download Full-text

siRNA as a potential therapy for COVID-19

Current Drug Delivery ◽

10.2174/1567201818666210805145320 ◽

2021 ◽

Vol 18 ◽

Author(s):

Ahmad Aljaberi ◽

Eman M. Migdadi ◽

Khalid M Abu Khadra ◽

Mahmoud Abu Samak ◽

Iman A Basheti ◽

...

Keyword(s):

Current Knowledge ◽

Therapeutic Option ◽

Target Selection ◽

Genome Structure ◽

Specific Treatment ◽

Viral Escape ◽

World Health ◽

Corona Viruses

: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV2) is a highly contagious virus causing COVID-19 disease that severely impacted the world health, education, and economy systems in 2020. The numbers of infection cases and reported deaths are still increasing with no specific treatment identified yet to halt this pandemic. Currently, several proposed treatments are under preclinical and clinical investigations now, alongside the race to vaccinate to as much individuals as possible. The genome of SARS-CoV2 share similar gene organization as other viruses in the Coronaviridae family. It is a positive-sense, single-stranded RNA. This feature suggests that RNA interference (RNAi) is an attractive prophylactic and therapeutic option for the control of this pandemic and other possible future pandemics of the corona viruses. RNAi utilizes the use of siRNA molecules which are 21-29 nt duplexes RNA molecules that intervene with targeted gene expression in the cytoplasm by a specific mechanism of complementary destruction of mRNA. Previous experience with SARS-CoV and Middle East respiratory syndrome (MERS) showed that siRNA molecules were effective against these viruses in vitro and in vivo. Moreover, there have been extensive advances in siRNA technology in the past decade from chemistry and target selection considerations; which concluded with the successful approval of two commercial products based on siRNA technology. In addition, the current knowledge of the genome structure and functionality of the corona viruses enables the recognition of conserved sequences to optimize siRNA targeting and avoid viral escape through mutations, either for the current SARS-CoV2 as well as future corona viruses.

Download Full-text

Identification of a neutralizing epitope within minor repeat region of Plasmodium falciparum CS protein

npj Vaccines ◽

10.1038/s41541-020-00272-6 ◽

2021 ◽

Vol 6 (1) ◽

Author(s):

J. Mauricio Calvo-Calle ◽

Robert Mitchell ◽

Rita Altszuler ◽

Caroline Othoro ◽

Elizabeth Nardin

Keyword(s):

Monoclonal Antibodies ◽

Neutralizing Antibodies ◽

In Vivo Studies ◽

Repeat Region ◽

Fine Specificity ◽

Humoral Immune ◽

Major Surface ◽

Murine Monoclonal Antibodies

AbstractMalaria remains a major cause of morbidity and mortality worldwide with 219 million infections and 435,000 deaths predominantly in Africa. The infective Plasmodium sporozoite is the target of a potent humoral immune response that can protect murine, simian and human hosts against challenge by malaria-infected mosquitoes. Early murine studies demonstrated that sporozoites or subunit vaccines based on the sporozoite major surface antigen, the circumsporozoite (CS) protein, elicit antibodies that primarily target the central repeat region of the CS protein. In the current murine studies, using monoclonal antibodies and polyclonal sera obtained following immunization with P. falciparum sporozoites or synthetic repeat peptides, we demonstrate differences in the ability of these antibodies to recognize the major and minor repeats contained in the central repeat region. The biological relevance of these differences in fine specificity was explored using a transgenic P. berghei rodent parasite expressing the P. falciparum CS repeat region. In these in vitro and in vivo studies, we demonstrate that the minor repeat region, comprised of three copies of alternating NANP and NVDP tetramer repeats, contains an epitope recognized by sporozoite-neutralizing antibodies. In contrast, murine monoclonal antibodies specific for the major CS repeats (NANP)n could be isolated from peptide-immunized mice that had limited or no sporozoite-neutralizing activity. These studies highlight the importance of assessing the fine specificity and functions of antirepeat antibodies elicited by P. falciparum CS-based vaccines and suggest that the design of immunogens to increase antibody responses to minor CS repeats may enhance vaccine efficacy.

Download Full-text

MODL-29. EVALUATING TUMOR-IMMUNE INTERACTIONS IN MOUSE MODELS OF DIFFUSE INTRINSIC PONTINE GLIOMA

Neuro-Oncology ◽

10.1093/neuonc/noaa222.602 ◽

2020 ◽

Vol 22 (Supplement_3) ◽

pp. iii417-iii417

Author(s):

Robin Furnish ◽

Heather Bear ◽

Xin Wei ◽

Timothy Phoenix

Keyword(s):

Mouse Models ◽

Diffuse Intrinsic Pontine Glioma ◽

In Vivo Studies ◽

In Vitro Assays ◽

Preclinical Studies ◽

Check Point ◽

Pontine Glioma ◽

Therapeutic Benefits

Abstract BACKGROUND While adult gliomas show some level of immune cell infiltration, diffuse intrinsic pontine glioma (DIPG) is characterized as having an “immune cold” state. We have developed new immunocompetent mouse models of DIPG. These models faithfully recapitulate the pathological hallmarks of DIPG and provides a unique platform to investigate immune modulatory therapies and potential therapeutic benefits of check point inhibitor combination therapies. METHODS To evaluate the effects of CDK4/6 inhibition (CDK4/6i) on cell proliferation and immune interactions we performed a series of in vitro and in vivo studies using DIPG mouse models. In vitro assays included dose response curves, transcriptional profiling, and MHC1 expression. In vivo preclinical studies treated mouse models with CDK4/6i with or without immune check-point inhibitors (ICI). We also examined other candidate immune modulatory therapies in vitro. RESULTS CDK4/6i (Abemeciclib) reduced proliferation of DIPG cells derived from mouse models, and displayed a modest increase in immune activation by MHC1 expression and transcriptome. Pilot in vivo preclinical studies did not show any significant changes in DIPG proliferation or immune changes with CDK4/6i treatment, ICI treatment, or the combination of CDK4/6i + ICI. In vitro testing of other immune-modulatory drugs identified additional candidates that can be tested in vivo. CONCLUSION CDK4/6i displayed in vitro action, but lacked efficacy in DIPG mouse models in vivo. Further use of spontaneous DIPG mouse models will provide a rapid preclinical platform to evaluate in vivo tumor-immune interactions, drug efficacy, and mechanisms of resistance.

Download Full-text

Murine monoclonal antibodies against murine uPA receptor produced in gene-deficient mice: Inhibitory effects on receptormediated uPA activity in vitro and in vivo

Thrombosis and Haemostasis ◽

10.1160/th06-11-0644 ◽

2007 ◽

Vol 97 (06) ◽

pp. 1013-1022 ◽

Cited By ~ 14

Author(s):

Jesper Pass ◽

Annika Jögi ◽

Ida Lund ◽

Birgitte Rønø ◽

Morten Rasch ◽

...

Keyword(s):

Monoclonal Antibodies ◽

Lethal Dose ◽

In Vivo Studies ◽

Plasminogen Activation ◽

Amino Terminal ◽

Anthrax Toxins ◽

Murine Monoclonal Antibodies ◽

Deficient Mice

SummaryBinding of urokinase plasminogen activator (uPA) to its cellular receptor, uPAR, potentiates plasminogen activation and localizes it to the cell surface. Focal plasminogen activation is involved in both normal and pathological tissue remodeling processes including cancer invasion. The interaction between uPA and uPAR therefore represents a potential target for anti-invasive cancer therapy. Inhibitors of the human uPA-uPAR interaction have no effect in the murine system. To enable in-vivo studies in murine cancer models we have now generated murine monoclonal antibodies (mAbs) against murine uPAR (muPAR) by immunizing uPAR-deficient mice with recombinant muPAR and screened for antibodies, which inhibit the muPA-muPAR interaction. Two of the twelve mAbs obtained, mR1 and mR2, interfered with the interaction between muPAR and the amino-terminal fragment of muPA (mATF) when analyzed by surface plasmon resonance. The epitope for mR1 is located on domain I of muPAR, while that of mR2 is on domains (II-III). In cell binding experiments using radiolabelled mATF, the maximal inhibition obtained with mR1 was 85% while that obtained with mR2 was 50%. The IC50 value for mR1 was 0.67 nM compared to 0.14 nM for mATF. In an assay based on modified anthrax toxins, requiring cell-bound muPA activity for its cytotoxity, a ~50% rescue of the cells could be obtained by addition of mR1. Importantly, in-vivo efficacy of mR1 was demonstrated by the ability of mR1 to rescue mice treated with a lethal dose of uPA-activatable anthrax toxins.

Download Full-text

An assessment of the efficacies and therapeutic interventions of homoeopathic medicines in combating viral disorders with implications in the treatment of SARS-CoV-2 (Covid-19), a global pandemic

10.31219/osf.io/tj6dn ◽

2020 ◽

Author(s):

Joy Kumar Dey ◽

Anupam Mukherjee ◽

Sanjay Kumar Dey ◽

Mukut Pratap Udayat ◽

Abhishek Pramanik ◽

...

Keyword(s):

Middle Eastern ◽

Biologically Active ◽

Therapeutic Interventions ◽

In Vivo Studies ◽

The Public ◽

Corona Virus ◽

Global Pandemic ◽

Global Epidemiology

The prevalence of Severe Acute Respiratory Syndrome- Corona Virus-2 (SARS-CoV-2) has undergone a historic transition from December 2019 to April 2020. Under the current circumstances, SARS-CoV-2 has become a key problem for the public health and economic steadiness of the global fraternity. Based on ample of evidence from the global epidemiology of SARS-CoV-2 and MERS-CoV (Middle Eastern Respiratory Syndrome- Corona virus) scientists and physicians strappingly consider these viruses share structural and functional similarities of selected biologically active enzymes namely, 3CLpro, PLpro and RdRp. Ultra-diluted homoeopathic medicine has the legacy to combat infectious as well as viral diseases since last two centuries. Thus, existing antiviral homoeopathic therapies were meta-analysed in the current study and the need of appropriate clinical validation with proper in vitro as well as in vivo studies prior to make clinical endorsements in treating Covid-19 patients with homoeopathic medicines has been explained.

Download Full-text

Targeting dysregulation signatures of p53-MDM2 interactions to identify newer small molecule inhibitors for cancer therapy: Insight from computational direction

10.21203/rs.3.rs-217761/v1 ◽

2021 ◽

Author(s):

Prosper Obed Chukwuemeka ◽

Haruna Isiyaku Umar ◽

Opeyemi Iwaloye ◽

Oluwaseyi Matthew Oretade ◽

Christopher Busayo Olowosoke ◽

...

Keyword(s):

Binding Affinity ◽

Small Molecule ◽

Small Molecule Inhibitors ◽

Therapeutic Option ◽

Pharmacophore Model ◽

In Vivo Studies ◽

Hydrogen Bond Acceptor ◽

Potential Inhibitors

Abstract Dysregulation of the p53-MDM2 interactions has been implicated in majority of human tumors presenting a target for finding small molecule inhibitors. In this study, a training set of 17 experimentally tested inhibitors of MDM2 was used to develop series of pharmacophore models among which a four-featured (AHRR_1) model with one hydrogen bond acceptor, one hydrophobic group and two aromatic ring features and characterized by a survival score of 4.176 was considered significant among the top ranked generated hypothesis. Further, the model was validated by an external set of actives and decoy molecules and was found to exhibit encouraging statistical attributes (such as AUC > 0.7, BEDROC > 0.5 and EF > 1.0 etc). The model was used to screen the ZINC compound database, from the database, the top best 1375 hits satisfying the pharmacophore model was were docked to MDM2 protein to identify the likely interactions of the compounds as well as their binding affinity with MDM2. Further, druglikeness and pharmacokinetic properties screening on top-ranked compounds with higher binding affinity than reference inhibitors revealed four compounds (ZINC02639178, ZINC38933175, ZINC77969611, and ZINC06752762) with suitable pharmacological properties including low ligand toxicity. Investigation of the dynamic behaviour of each candidate inhibitors in complex with MDM2 via molecular dynamic simulation suggested ZINC02639178 and ZINC06752762 as the most potential inhibitors. Thus, these compounds may emerged as therapeutic option for cancer treatment after extensive in vitro and in vivo studies.

Download Full-text