The outbreak of coronavirus disease 19 (COVID-19) has highlighted the demand for vaccines that are safe and effective in inducing systemic and airway mucosal immunity against the aerosol transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this study, we developed a novel helper-dependent adenoviral vector-based COVID-19 mucosal vaccine encoding a full-length SARS-CoV-2 spike protein (HD-Ad-FS). Through intranasal immunization (single-dose and prime-boost regimens), we demonstrated that the HD-Ad-FS was immunogenic and elicited potent systemic and airway mucosal protection in BALB/c mice, transgenic ACE2 (hACE2) mice, and hamsters.
View Article and Find Full Text PDFUnlabelled: This case report details the complex diagnostic odyssey of a 60-year-old female grappling with chronic liver disease, initially diagnosed with hepatic encephalopathy (HE). Despite initial treatment with lactulose and rifaximin, her neurological symptoms worsened, leading to the identification of concurrent acquired hepatocerebral degeneration (AHD). This condition is characterised by cognitive decline, movement disorders and distinctive imaging abnormalities.
View Article and Find Full Text PDFOur understanding of the quality of cellular and humoral immunity conferred by COVID-19 vaccination alone versus vaccination plus SARS-CoV-2 breakthrough (BT) infection remains incomplete. While the current (2023) SARS-CoV-2 immune landscape of Canadians is complex, in late 2021 most Canadians had either just received a third dose of COVID-19 vaccine, or had received their two-dose primary series and then experienced an Omicron BT. Herein we took advantage of this coincident timing to contrast cellular and humoral immunity conferred by three doses of vaccine versus two doses plus BT.
View Article and Find Full Text PDFAmnestic mild cognitive impairment (aMCI) is a predementia stage of Alzheimer's disease associated with dysfunctional episodic memory and limited treatment options. We aimed to characterize feasibility, clinical, and biomarker effects of noninvasive neurostimulation for aMCI. 13 individuals with aMCI received eight 60-minute sessions of 40-Hz (gamma) transcranial alternating current stimulation (tACS) targeting regions related to episodic memory processing.
View Article and Find Full Text PDFThe spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and other coronaviruses mediates host cell entry and is S-acylated on multiple phylogenetically conserved cysteine residues. Multiple protein acyltransferase enzymes have been reported to post-translationally modify spike proteins; however, strategies to exploit this modification are lacking. Using resin-assisted capture MS, we demonstrate that the spike protein is S-acylated in SARS-CoV-2-infected human and monkey epithelial cells.
View Article and Find Full Text PDFStandardized neuropsychological assessments of older adults are important for both clinical diagnosis and biobehavioral research. Over decades, in-person testing has been the basis for population normative values that rank cognitive performance by demographic status. Most recently, digital tools have enabled remote data collection for cognitive measures, which offers the significant promise to extend the basis for normative values to be more inclusive of a larger cross section of the older population.
View Article and Find Full Text PDFAlthough SARS-CoV-2 infects the upper respiratory tract, we know little about the amount, type, and kinetics of antibodies (Ab) generated in the oral cavity in response to COVID-19 vaccination. We collected serum and saliva samples from participants receiving two doses of mRNA COVID-19 vaccines and measured the level of anti-SARS-CoV-2 Ab. We detected anti-Spike and anti-Receptor Binding Domain (RBD) IgG and IgA, as well as anti-Spike/RBD associated secretory component in the saliva of most participants after dose 1.
View Article and Find Full Text PDFConvalescent coronavirus disease 2019 (COVID-19) subjects who receive BNT162b2 develop robust antibody responses against SARS-CoV-2. However, our understanding of the clonal B cell response pre- and post-vaccination in such individuals is limited. Here we characterized B cell phenotypes and the BCR repertoire after BNT162b2 immunization in two convalescent COVID-19 subjects.
View Article and Find Full Text PDFSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) induces T cell, B cell, and Ab responses that are detected for several months in recovered individuals. Whether this response resembles a typical respiratory viral infection is a matter of debate. In this study, we followed T cell and Ab responses in 24 mainly nonhospitalized human subjects who had recovered from PCR-confirmed SARS-CoV-2 infection at two time points (median of 45 and 145 d after symptom onset).
View Article and Find Full Text PDFBackground: The ongoing COVID-19 pandemic has resulted in 185 million recorded cases and over 4 million deaths worldwide. Several COVID-19 vaccines have been approved for emergency use in humans and are being used in many countries. However, all the approved vaccines are administered by intramuscular injection and this may not prevent upper airway infection or viral transmission.
View Article and Find Full Text PDFThe COVID-19 pandemic has resulted in a worldwide health crisis. Rapid diagnosis, new therapeutics and effective vaccines will all be required to stop the spread of COVID-19. Quantitative evaluation of serum antibody levels against the SARS-CoV-2 virus provides a means of monitoring a patient's immune response to a natural viral infection or vaccination, as well as evidence of a prior infection.
View Article and Find Full Text PDFSARS-CoV-2 is a respiratory pathogen that can cause severe disease in at-risk populations but results in asymptomatic infections or a mild course of disease in the majority of cases. We report the identification of SARS-CoV-2-reactive B cells in human tonsillar tissue obtained from children who were negative for coronavirus disease 2019 prior to the pandemic and the generation of mAbs recognizing the SARS-CoV-2 Spike protein from these B cells. These Abs showed reduced binding to Spike proteins of SARS-CoV-2 variants and did not recognize Spike proteins of endemic coronaviruses, but subsets reacted with commensal microbiota and exhibited SARS-CoV-2-neutralizing potential.
View Article and Find Full Text PDFNeutralizing antibodies (nAbs) hold promise as therapeutics against COVID-19. Here, we describe protein engineering and modular design principles that have led to the development of synthetic bivalent and tetravalent nAbs against SARS-CoV-2. The best nAb targets the host receptor binding site of the viral S-protein and tetravalent versions block entry with a potency exceeding bivalent nAbs by an order of magnitude.
View Article and Find Full Text PDFSARS-CoV-2 is a newly emerged betacoronavirus and the causative agent for the COVID-19 pandemic. Antibodies recognizing the viral spike protein are instrumental in natural and vaccine-induced immune responses to the pathogen and in clinical diagnostic and therapeutic applications. Unlike conventional immunoglobulins, the variable lymphocyte receptor antibodies of jawless vertebrates are structurally distinct, indicating that they may recognize different epitopes.
View Article and Find Full Text PDFThough distinct pathological entities, corticobasal degeneration (CBD) and progressive supranuclear palsy (PSP) share multiple biochemical and genetic features suggesting overlapping pathophysiology. We report the case of a patient with an 18-year clinical course consistent with behavioral variant frontotemporal dementia. The neuropathological assessment revealed unclassifiable frontotemporal lobar degeneration with tau-immunoreactive inclusions sharing features of both CBD and PSP.
View Article and Find Full Text PDFBetter diagnostic tools are needed to combat the ongoing COVID-19 pandemic. Here, to meet this urgent demand, we report a homogeneous immunoassay to detect IgG antibodies against SARS-CoV-2. This serological assay, called SATiN, is based on a tri-part Nanoluciferase (tNLuc) approach, in which the spike protein of SARS-CoV-2 and protein G, fused respectively to two different tNLuc tags, are used as antibody probes.
View Article and Find Full Text PDFAccurate, rapid, and low-cost molecular diagnostics is essential in managing outbreaks of infectious diseases, such as the pandemic of coronavirus disease 2019 (COVID-19). Accordingly, microfluidic paper-based analytical devices (μPADs) have emerged as promising diagnostic tools. Among the extensive efforts to improve the performance and usability of diagnostic tools, biosensing mechanisms based on electrochemical impedance spectroscopy (EIS) have shown great promise because of their label-free operation and high sensitivity.
View Article and Find Full Text PDFNeurol Clin Neurosci
July 2020
As ictal semiology is increasingly understood to arise from epileptogenic networks, high-frequency oscillation propagation patterns are helping elucidate networks relevant for surgical planning. Musical automatisms, a well-documented but very rare phenomenon of epilepsy, have yet to be examined as a manifestation of high-frequency propagation in the public literature. In our current study, we report a rare case intractable epilepsy with ictal humming whose epileptogenic zone was associated with the non-dominant left anterior medial temporal region.
View Article and Find Full Text PDFNeutralizing antibodies (nAbs) hold promise as effective therapeutics against COVID-19. Here, we describe protein engineering and modular design principles that have led to the development of synthetic bivalent and tetravalent nAbs against SARS-CoV-2. The best nAb targets the host receptor binding site of the viral S-protein and its tetravalent versions can block entry with a potency that exceeds the bivalent nAbs by an order of magnitude.
View Article and Find Full Text PDFEnzyme replacement therapy, in which a functional copy of an enzyme is injected either systemically or directly into the brain of affected individuals, has proven to be an effective strategy for treating certain lysosomal storage diseases. The inefficient uptake of recombinant enzymes via the mannose-6-phosphate receptor, however, prohibits the broad utility of replacement therapy. Here, to improve the efficiency and efficacy of lysosomal enzyme uptake, we exploited the strategy used by diphtheria toxin to enter into the endolysosomal network of cells by creating a chimera between the receptor-binding fragment of diphtheria toxin and the lysosomal hydrolase TPP1.
View Article and Find Full Text PDFThere is a pressing need for an in-depth understanding of immunity to SARS-CoV-2. In this study, we investigated human T cell recall responses to fully glycosylated spike trimer, recombinant N protein, as well as to S, N, M, and E peptide pools in the early convalescent phase and compared them with influenza-specific memory responses from the same donors. All subjects showed SARS-CoV-2-specific T cell responses to at least one Ag.
View Article and Find Full Text PDF