Discovery of Nanosota-EB1 and -EB2 as Novel Nanobody Inhibitors Against Ebola Virus Infection.

The Ebola filovirus (EBOV) poses a serious threat to global health and national security. Nanobodies, a type of single-domain antibody, have demonstrated promising therapeutic potential. We identified two anti-EBOV nanobodies, Nanosota-EB1 and Nanosota-EB2, which specifically target the EBOV glycoprotein (GP).

Discovery of Nanosota-9 as anti-Omicron nanobody therapeutic candidate.

Omicron subvariants of SARS-CoV-2 continue to pose a significant global health threat. Nanobodies, single-domain antibodies derived from camelids, are promising therapeutic tools against pandemic viruses due to their favorable properties. In this study, we identified a novel nanobody, Nanosota-9, which demonstrates high potency against a wide range of Omicron subvariants both in vitro and in a mouse model.

Targeting soluble amyloid-beta oligomers with a novel nanobody.

The classical amyloid cascade hypothesis postulates that the aggregation of amyloid plaques and the accumulation of intracellular hyperphosphorylated Tau tangles, together, lead to profound neuronal death. However, emerging research has demonstrated that soluble amyloid-β oligomers (SAβOs) accumulate early, prior to amyloid plaque formation. SAβOs induce memory impairment and disrupt cognitive function independent of amyloid-β plaques, and even in the absence of plaque formation.

TARGETING SOLUBLE AMYLOID-BETA OLIGOMERS WITH A NOVEL NANOBODY.

The classical amyloid cascade hypothesis postulates that the aggregation of amyloid plaques and the accumulation of intracellular hyperphosphorylated Tau tangles, together, lead to profound neuronal death. However, emerging research has demonstrated that soluble amyloid-β oligomers (SAβOs) accumulate early, prior to amyloid plaque formation. SAβOs induce memory impairment and disrupt cognitive function independent of amyloid-β plaques, and even in the absence of plaque formation.

Engineering therapeutic monoclonal antibodies.

The use of human antibodies as biologic therapeutics has revolutionized patient care throughout fields of medicine. As our understanding of the many roles antibodies play within our natural immune responses continues to advance, so will the number of therapeutic indications for which an mAb will be developed. The great breadth of function, long half-life, and modular structure allow for nearly limitless therapeutic possibilities.

Nanobodies against C. difficile TcdA and TcdB reveal unexpected neutralizing epitopes and provide a toolkit for toxin quantitation in vivo.

Clostridioides difficile is a leading cause of antibiotic-associated diarrhea and nosocomial infection in the United States. The symptoms of C. difficile infection (CDI) are associated with the production of two homologous protein toxins, TcdA and TcdB.

Discovery of Nanosota-2, -3, and -4 as super potent and broad-spectrum therapeutic nanobody candidates against COVID-19.

The COVID-19 pandemic exposed limitations of conventional antibodies as therapeutics, including high cost, limited potency, ineffectiveness against new viral variants, and primary reliance on injection-only delivery. Nanobodies are single-domain antibodies with therapeutic potentials. We discovered three anti-SARS-CoV-2 nanobodies, named Nanosota-2, -3, and -4, from an immunized alpaca.

A new paradigm for regulation of protein phosphatase 2A function via Src and Fyn kinase-mediated tyrosine phosphorylation.

Protein phosphatase 2A (PP2A) is a major phospho-Ser/Thr phosphatase and a key regulator of cellular signal transduction pathways. While PP2A dysfunction has been linked to human cancer and neurodegenerative disorders such as Alzheimer's disease (AD), PP2A regulation remains relatively poorly understood. It has been reported that the PP2A catalytic subunit (PP2Ac) is inactivated by a single phosphorylation at the Tyr307 residue by tyrosine kinases such as v-Src.

Human IgE mAbs identify major antigens of parasitic worm infection.

Background: Much of our understanding of the targets of IgE comes from studies of allergy, though little is known about the natural immunogenic targets seen after parasitic worm infections.

Objective: We used human monoclonal antibodies (mAbs) for an unbiased and comprehensive characterization of the immunodominant antigens targeted by IgE in conditions like allergy or helminth infection that are associated with elevated levels of IgE.

Methods: Using human hybridoma technology to immortalize IgE encoding B-cells from peripheral blood of subjects with filarial infections and elevated IgE, we generated naturally occurring human IgE mAbs.

Longitudinal Consumption of Ergothioneine Reduces Oxidative Stress and Amyloid Plaques and Restores Glucose Metabolism in the 5XFAD Mouse Model of Alzheimer's Disease.

Ergothioneine (ERGO) is a unique antioxidant and a rare amino acid available in fungi and various bacteria but not in higher plants or animals. Substantial research data indicate that ERGO is a physiological antioxidant cytoprotectant. Different from other antioxidants that need to breach the blood-brain barrier to enter the brain parenchyma, a specialized transporter called OCTN1 has been identified for transporting ERGO to the brain.

"The structure of the Type III secretion system export gate with CdsO, an ATPase lever arm".

Type III protein secretion systems (T3SS) deliver effector proteins from the Gram-negative bacterial cytoplasm into a eukaryotic host cell through a syringe-like, multi-protein nanomachine. Cytosolic components of T3SS include a portion of the export apparatus, which traverses the inner membrane and features the opening of the secretion channel, and the sorting complex for substrate recognition and for providing the energetics required for protein secretion. Two components critical for efficient effector export are the export gate protein and the ATPase, which are proposed to be linked by the central stalk protein of the ATPase.

Small Molecule Inhibitor Screen Reveals Calcium Channel Signaling as a Mechanistic Mediator of TcdB-Induced Necrosis.

is the leading cause of nosocomial diarrhea in the United States. The primary virulence factors are two homologous glucosyltransferase toxins, TcdA and TcdB, that inactivate host Rho-family GTPases. The glucosyltransferase activity has been linked to a "cytopathic" disruption of the actin cytoskeleton and contributes to the disruption of tight junctions and the production of pro-inflammatory cytokines.

What one lipid giveth, another taketh away.

Acid sphingomyelinase deficiency, which prevents degradation of sphingomyelin (SM), causes lysosomal SM overload both in mice and in patients with Niemann–Pick disease A or B. Altered cellular SM homeostasis disrupts the development and function of natural killer T cells by obstructing the presentation of lipid agonists by CD1d molecules.

A neutralizing antibody that blocks delivery of the enzymatic cargo of toxin TcdB into host cells.

infection is the leading cause of hospital-acquired diarrhea and is mediated by the actions of two toxins, TcdA and TcdB. The toxins perturb host cell function through a multistep process of receptor binding, endocytosis, low pH-induced pore formation, and the translocation and delivery of an N-terminal glucosyltransferase domain that inactivates host GTPases. Infection studies with isogenic strains having defined toxin deletions have established TcdB as an important target for therapeutic development.

Use of a neutralizing antibody helps identify structural features critical for binding of toxin TcdA to the host cell surface.

is a clinically significant pathogen that causes mild-to-severe (and often recurrent) colon infections. Disease symptoms stem from the activities of two large, multidomain toxins known as TcdA and TcdB. The toxins can bind, enter, and perturb host cell function through a multistep mechanism of receptor binding, endocytosis, pore formation, autoproteolysis, and glucosyltransferase-mediated modification of host substrates.

Crystal structure of Clostridium difficile toxin A.

Clostridium difficile infection is the leading cause of hospital-acquired diarrhoea and pseudomembranous colitis. Disease is mediated by the actions of two toxins, TcdA and TcdB, which cause the diarrhoea, as well as inflammation and necrosis within the colon. The toxins are large (308 and 270 kDa, respectively), homologous (47% amino acid identity) glucosyltransferases that target small GTPases within the host.

Crystal structure of toxin A.

infection is the leading cause of hospital-acquired diarrhoea and pseudomembranous colitis. Disease is mediated by the actions of two toxins, TcdA and TcdB, which cause the diarrhoea, as well as inflammation and necrosis within the colon. The toxins are large (308 and 270 kDa, respectively), homologous (47% amino acid identity) glucosyltransferases that target small GTPases within the host.

A Nonoligomerizing Mutant Form of Helicobacter pylori VacA Allows Structural Analysis of the p33 Domain.

Helicobacter pylori secretes a pore-forming VacA toxin that has structural features and activities substantially different from those of other known bacterial toxins. VacA can assemble into multiple types of water-soluble flower-shaped oligomeric structures, and most VacA activities are dependent on its capacity to oligomerize. The 88-kDa secreted VacA protein can undergo limited proteolysis to yield two domains, designated p33 and p55.

The three Type 2A protein phosphatases, PP2Ac, PP4c and PP6c, are differentially regulated by Alpha4.

Alpha4 is a non-canonical regulatory subunit of Type 2A protein phosphatases that interacts directly with the phosphatase catalytic subunits (PP2Ac, PP4c, and PP6c) and is upregulated in a variety of cancers. Alpha4 modulates phosphatase expression levels and activity, but the molecular mechanism of this regulation is unclear, and the extent to which the various Type 2A catalytic subunits associate with Alpha4 is also unknown. To determine the relative fractions of the Type 2A catalytic subunits associated with Alpha4, we conducted Alpha4 immunodepletion experiments in HEK293T cells and found that a significant fraction of total PP6c is associated with Alpha4, whereas a minimal fraction of total PP2Ac is associated with Alpha4.

Vaccine-elicited antibody that neutralizes H5N1 influenza and variants binds the receptor site and polymorphic sites.

Antigenic drift of circulating seasonal influenza viruses necessitates an international vaccine effort to reduce the impact on human health. A critical feature of the seasonal vaccine is that it stimulates an already primed immune system to diversify memory B cells to recognize closely related, but antigenically distinct, influenza glycoproteins (hemagglutinins). Influenza pandemics arise when hemagglutinins to which no preexisting adaptive immunity exists acquire the capacity to infect humans.

A gatekeeper chaperone complex directs translocator secretion during type three secretion.

Many Gram-negative bacteria use Type Three Secretion Systems (T3SS) to deliver effector proteins into host cells. These protein delivery machines are composed of cytosolic components that recognize substrates and generate the force needed for translocation, the secretion conduit, formed by a needle complex and associated membrane spanning basal body, and translocators that form the pore in the target cell. A defined order of secretion in which needle component proteins are secreted first, followed by translocators, and finally effectors, is necessary for this system to be effective.

Short forms of Ste20-related proline/alanine-rich kinase (SPAK) in the kidney are created by aspartyl aminopeptidase (Dnpep)-mediated proteolytic cleavage.

The Ste20-related kinase SPAK regulates sodium, potassium, and chloride transport in a variety of tissues. Recently, SPAK fragments, which lack the catalytic domain and are inhibitory to Na(+) transporters, have been detected in kidney. It has been hypothesized that the fragments originate from alternative translation start sites, but their precise origin is unknown.

Differential accessibility of a rotavirus VP6 epitope in trimers comprising type I, II, or III channels as revealed by binding of a human rotavirus VP6-specific antibody.

Previous human antibody studies have shown that the human VH1-46 antibody variable gene segment encodes much of the naturally occurring human B cell response to rotavirus and is directed to virus protein 6 (VP6). It is currently unknown why some of the VH1-46-encoded human VP6 monoclonal antibodies inhibit viral transcription while others do not. In part, there are affinity differences between antibodies that likely affect inhibitory activity, but we also hypothesize that there are differing modes of binding to VP6 that affect the ability to block the transcriptional pore on double-layered particles.