The Detection of Toxic Amyloid-β Fibril Fragments Through a Surface Plasmon Resonance Immunoassay.

Amyloid-β1-42 (Aβ42) forms highly stable and insoluble fibrillar structures, representing the principal components of the amyloid plaques present in the brain of Alzheimer's disease (AD) patients. The involvement of Aβ42 in AD-associated neurodegeneration has also been demonstrated, in particular for smaller and soluble aggregates (oligomers). Based on these findings and on genetic evidence, Aβ42 aggregates are considered key players in the pathogenesis of AD and targets for novel therapies.

Artificial Intelligence-Powered Molecular Docking and Steered Molecular Dynamics for Accurate scFv Selection of Anti-CD30 Chimeric Antigen Receptors.

Chimeric antigen receptor (CAR) T cells represent a revolutionary immunotherapy that allows specific tumor recognition by a unique single-chain fragment variable (scFv) derived from monoclonal antibodies (mAbs). scFv selection is consequently a fundamental step for CAR construction, to ensure accurate and effective CAR signaling toward tumor antigen binding. However, conventional in vitro and in vivo biological approaches to compare different scFv-derived CARs are expensive and labor-intensive.

Development of a Bispecific IgG1 Antibody Targeting BCMA and PDL1.

We designed, produced, and purified a novel IgG1-like, bispecific antibody (bsAb) directed against B-cell maturation antigen (BCMA), expressed by multiple myeloma (MM) cells, and an immune checkpoint inhibitor (ICI), PDL1, expressed in the MM microenvironment. The BCMA×PDL1 bsAb was fully characterized in vitro. BCMA×PDL1 bound specifically and simultaneously, with nM affinity, to both native membrane-bound antigens and to the recombinant soluble antigen fragments, as shown by immunophenotyping analyses and surface plasmon resonance (SPR), respectively.

A Comprehensive Technology Platform for the Rapid Discovery of Peptide Inhibitors against SARS-CoV-2 Pseudovirus Infection.

We developed and validated a technology platform for designing and testing peptides inhibiting the infectivity of SARS-CoV-2 spike protein-based pseudoviruses. This platform integrates target evaluation, in silico inhibitor design, peptide synthesis, and efficacy screening. We generated a cyclic peptide library derived from the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein and the angiotensin-converting enzyme 2 (ACE2) receptor.

Aβ1-6(D) peptide, effective on Aβ aggregation, inhibits tau misfolding and protects the brain after traumatic brain injury.

Alzheimer's disease (AD), the leading cause of dementia in older adults, is a double proteinopathy characterized by amyloid-β (Aβ) and tau pathology. Despite enormous efforts that have been spent in the last decades to find effective therapies, late pharmacological interventions along the course of the disease, inaccurate clinical methodologies in the enrollment of patients, and inadequate biomarkers for evaluating drug efficacy have not allowed the development of an effective therapeutic strategy. The approaches followed so far for developing drugs or antibodies focused solely on targeting Aβ or tau protein.

Amyposomes, a nanotechnological chaperone with anti-amyloidogenic activity.

Aim: The effect of liposomes bi-functionalized with phosphatidic acid and with a synthetic peptide derived from human apolipoprotein E has been evaluated on the aggregation features of different amyloidogenic proteins: human Amyloid β1-40 (Aβ), transthyretin (TTR) variant S52P, human β2microglobulin (β2m) variants ΔN6 and D76N, Serum Amyloid A (SAA).

Methods: The formation of fibrillar aggregates of the proteins was investigated by ThioflavinT fluorescence assay and validated by Atomic Force Microscopy.

Results: The results show that liposomes are preventing the transition of non-aggregated forms to the fibrillar state, with stronger effects on Aβ, β2m ΔN6 and SAA.

Rational Design of a Peptidomimetic Inhibitor of Gelsolin Amyloid Aggregation.

Gelsolin amyloidosis (AGel) is characterized by multiple systemic and ophthalmic features resulting from pathological tissue deposition of the gelsolin (GSN) protein. To date, no cure is available for the treatment of any form of AGel. More than ten single-point substitutions in the gene are responsible for the occurrence of the disease and, among them, D187N/Y is the most widespread variant.

A novel hotspot of gelsolin instability triggers an alternative mechanism of amyloid aggregation.

Gelsolin comprises six homologous domains, named G1 to G6. Single point substitutions in this protein are responsible for AGel amyloidosis, a hereditary disease causing progressive corneal lattice dystrophy, cutis laxa, and polyneuropathy. Although several different amyloidogenic variants of gelsolin have been identified, only the most common mutants present in the G2 domain have been thoroughly characterized, leading to clarification of the functional mechanism.

Doxycycline Inhibition of a Pseudotyped Virus Transduction Does Not Translate to Inhibition of SARS-CoV-2 Infectivity.

The rapid spread of the pandemic caused by the SARS-CoV-2 virus has created an unusual situation, with rapid searches for compounds to interfere with the biological processes exploited by the virus. Doxycycline, with its pleiotropic effects, including anti-viral activity, has been proposed as a therapeutic candidate for COVID-19 and about twenty clinical trials have started since the beginning of the pandemic. To gain information on the activity of doxycycline against SARS-CoV-2 infection and clarify some of the conflicting clinical data published, we designed in vitro binding tests and infection studies with a pseudotyped virus expressing the spike protein, as well as a clinically isolated SARS-CoV-2 strain.

A Surface Plasmon Resonance-Based Assay for Simultaneous Measurement of Serum Concentrations of Therapeutic Antibodies and Anti-Drug Antibodies.

The monitoring of the blood levels of therapeutic antibodies and their immune responses is proposed to guide and optimize therapy with these expensive drugs. We describe a novel Surface Plasmon Resonance (SPR)-based assay suitable for the simultaneous determination of serum concentrations of infliximab and anti-infliximab antibodies. The real-time detection by SPR avoids the incubation/washing steps of commonly used methods, thus allowing faster and more reliable measurements, in particular for low-affinity anti-drug antibodies.

Surface plasmon resonance unveils important pitfalls of enzyme-linked immunoassay for the detection of anti-infliximab antibodies in patients' sera.

Measurements of serum concentrations of therapeutic antibodies and anti-drug antibodies (ADA) can support clinical decisions for the management of non-responders, optimizing the therapy. In the present study we compared the results obtained by classical ELISA and a recently proposed surface plasmon resonance (SPR)-based immunoassay, in 76 patients receiving infliximab for inflammatory bowel diseases. The two methods indicated very similar serum concentrations of the drug, but there were striking differences as regards ADA.

Can Antiviral Activity of Licorice Help Fight COVID-19 Infection?

The phytotherapeutic properties of (licorice) extract are mainly attributed to glycyrrhizin (GR) and glycyrrhetinic acid (GA). Among their possible pharmacological actions, the ability to act against viruses belonging to different families, including SARS coronavirus, is particularly important. With the COVID-19 emergency and the urgent need for compounds to counteract the pandemic, the antiviral properties of GR and GA, as pure substances or as components of licorice extract, attracted attention in the last year and supported the launch of two clinical trials.

Nonphosphorylated tau slows down Aβ aggregation, binds to Aβ oligomers, and reduces Aβ toxicity.

The formation of neurofibrillary tangles and amyloid plaques accompanies the progression of Alzheimer's disease. Tangles are made of fibrillar aggregates formed by the microtubule-associated protein tau, whereas plaques comprise fibrillar forms of amyloid-beta (Aβ). Both form toxic oligomers during aggregation and are thought to interact synergistically to each promote the accumulation of the other.

Characterization of the neutralizing anti-emicizumab antibody in a patient with hemophilia A and inhibitor.

Background: The genetically engineered, humanized, bispecific monoclonal antibody emicizumab (Hemlibra) that mimics the cofactor activity of activated factor VIII (FVIII) has been approved for treatment of hemophilia A patients with and without inhibitor. In the pivotal premarketing clinical trials, emicizumab prophylaxis significantly reduced bleeding rates compared with previous treatments and was well tolerated. However, a consequence of this novel therapy may be the host immune response to a foreign protein.

A portable optical-fibre-based surface plasmon resonance biosensor for the detection of therapeutic antibodies in human serum.

Different lines of evidence indicate that monitoring the blood levels of therapeutic antibodies, characterized by high inter-individual variability, can help to optimize clinical decision making, improving patient outcomes and reducing costs with these expensive treatments. A surface plasmon resonance (SPR)-based immunoassay has recently been shown to allow highly reliable and robust monitoring of serum concentrations of infliximab, with significant advantages over classical ELISA. The next level of advancement would be the availability of compact and transportable SPR devices suitable for easy, fast and cheap point-of-care analysis.

The Anti-Amyloidogenic Action of Doxycycline: A Molecular Dynamics Study on the Interaction with Aβ42.

The pathological aggregation of amyloidogenic proteins is a hallmark of many neurological diseases, including Alzheimer's disease and prion diseases. We have shown both in vitro and in vivo that doxycycline can inhibit the aggregation of Aβ42 amyloid fibrils and disassemble mature amyloid fibrils. However, the molecular mechanisms of the drug's anti-amyloidogenic property are not understood.

A Surface Plasmon Resonance-based assay to measure serum concentrations of therapeutic antibodies and anti-drug antibodies.

Therapeutic drug and immunogenicity monitoring (TDIM) is increasingly proposed to guide therapy with biologics, characterised by high inter-individual variability of their blood levels, to permit objective decisions for the management of non-responders and reduce unnecessary interventions with these expensive treatments. However, TDIM has not yet entered clinical practice partly because of uncertainties regarding the accuracy and precision of enzyme-linked immunosorbent assays (ELISA). Here we report the characterisation of a novel surface plasmon resonance (SPR)-based TDIM, applied to the measurement of serum concentrations of infliximab, an antibody against tumour necrosis factor α (anti-TNFα), and anti-infliximab antibodies.

Cellular prion protein neither binds to alpha-synuclein oligomers nor mediates their detrimental effects.

α-Synuclein oligomers are crucial players in the pathogenesis of Parkinson's disease. Some mechanisms involved in α-synuclein oligomer detrimental effects include membrane damage, neuroinflammation and protein-protein interactions. Recently, the cellular prion protein (PrPC) emerged as an interactor of α-synuclein oligomers, apparently mediating their detrimental activities.

Doxycycline counteracts neuroinflammation restoring memory in Alzheimer's disease mouse models.

β-Amyloid oligomers (AβOs) and neuroinflammation are 2 main culprits to counteract in Alzheimer's disease (AD). Doxycycline (DOXY) is a second generation antibiotic of the tetracycline class that are promising drugs tested in many clinical trials for a number of different pathologies. DOXY is endowed with antiamyloidogenic properties and better crosses the blood-brain barrier, but its efficacy has never been tested in AD mice.

Utilization of the Monte Carlo Method to Build up QSAR Models for Hemolysis and Cytotoxicity of Antimicrobial Peptides.

Background: Traditional quantitative structure - property / activity relationships (QSPRs/QSARs) are based on representation of molecular structure by molecular graph or simplified molecular input-line entry system (SMILES). It is an attractive idea to develop predictive models for large molecules in general and for peptides in particular. However, the representation of these molecules by molecular graph or SMILES is problematic owing to large size of these molecules.

QSAR model for blood-brain barrier permeation.

Background And Objective: Predicting blood-brain barrier permeability for novel compounds is an important goal for neurotherapeutics-focused drug discovery. It is impossible to determine experimentally the blood-brain barrier partitioning of all possible candidates. Consequently, alternative evaluation methods based on computational models are desirable or even necessary.

Humanin Specifically Interacts with Amyloid-β Oligomers and Counteracts Their in vivo Toxicity.

The 24-residue peptide humanin (HN) has been proposed as a peptide-based inhibitor able to interact directly with amyloid-β (Aβ) oligomers and interfere with the formation and/or biological properties of toxic Aβ species. When administered exogenously, HN, or its synthetic S14G-derivative (HNG), exerted multiple cytoprotective effects, counteracting the Aβ-induced toxicity. Whether these peptides interact directly with Aβ, particularly with the soluble oligomeric assemblies, remains largely unknown.