The proteome of the blood-brain barrier in rat and mouse: highly specific identification of proteins on the luminal surface of brain microvessels by in vivo glycocapture.

Background: The active transport of molecules into the brain from blood is regulated by receptors, transporters, and other cell surface proteins that are present on the luminal surface of endothelial cells at the blood-brain barrier (BBB). However, proteomic profiling of proteins present on the luminal endothelial cell surface of the BBB has proven challenging due to difficulty in labelling these proteins in a way that allows efficient purification of these relatively low abundance cell surface proteins.

Methods: Here we describe a novel perfusion-based labelling workflow: in vivo glycocapture.

Sedimentary records of contaminant inputs in Frobisher Bay, Nunavut.

Contaminants, such as polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), heavy metals, and per and polyfluoroalkyl substances (PFASs), primarily reach the Arctic through long-range atmospheric and oceanic transport. However, local sources within the Arctic also contribute to the levels observed in the environment, including legacy sources and new sources that arise from activities associated with increasing commercial and industrial development. The City of Iqaluit in Frobisher Bay, Nunavut (Canada), has seen rapid population growth and associated development during recent decades yet remains a site of interest for ocean protection, where Inuit continue to harvest country food.

Cell surface profiling of cultured cells by direct hydrazide capture of oxidized glycoproteins.

Glycoproteins are a particularly interesting subset of the cellular proteome as a high proportion of proteins present on the extracellular cell surface are glycosylated. These cell surface proteins are ideal targets for biologic drug therapies or for diagnostics tests. Here, we describe a modification of the well-described Cell Surface Capture (CSC) method for the selective isolation and identification of cell surface glycoproteins that contain N-linked carbohydrates.

Synthetic Multicomponent Nanovaccines Based on the Molecular Co-assembly of β-Peptides Protect against Influenza A Virus.

Peptides with the ability to self-assemble into nanoparticles have emerged as an attractive strategy to design antigen delivery platforms for subunit vaccines. While toll-like receptor (TLR) agonists are promising immunostimulants, their use as soluble agents is limited by their rapid clearance and off-target inflammation. Herein, we harnessed molecular co-assembly to prepare multicomponent cross-β-sheet peptide nanofilaments exposing an antigenic epitope derived from the influenza A virus and a TLR agonist.

Squaramide Tethered Clindamycin, Chloroquine, and Mortiamide Hybrids: Design, Synthesis, and Antimalarial Activity.

Malaria remains one of the major health problems in the world. In this work, a series of squaramide tethered chloroquine, clindamycin, and mortiamide D hybrids have been synthesized to assess their antiplasmodial activity against 3D7 (chloroquine-sensitive) and Dd2 strains of . The most active compound, a simple chloroquine analogue, displayed low nanomolar IC value against both strains (3 nM for 3D7 strain and 18 nM for Dd2 strain).

Protecting-group-free synthesis of clevudine (L-FMAU), a treatment of the hepatitis B virus.

Unnatural nucleoside analogues are valuable research and clinical tools as antiproliferative, antibacterial or antiviral agents. In this context, clevudine (L-FMAU), a reverse transcriptase inhibitor, is currently used for the treatment of the hepatitis B virus. Herein, we describe a new strategy for the preparation of clevudine.

COVID-19 vaccine humoral response in frequent platelet donors with plateletpheresis-associated lymphopenia.

Background: Plateletpheresis involves platelet separation and collection from whole blood while other blood cells are returned to the donor. Because platelets are replaced faster than red blood cells, as many as 24 donations can be done annually. However, some frequent apheresis platelet donors (>20 donations annually) display severe plateletpheresis-associated lymphopenia; in particular, CD4 T but not B cell numbers are decreased.

A retrospective cohort analysis of the Yale pediatric genomics discovery program.

The Pediatric Genomics Discovery Program (PGDP) at Yale uses next-generation sequencing (NGS) and translational research to evaluate complex patients with a wide range of phenotypes suspected to have rare genetic diseases. We conducted a retrospective cohort analysis of 356 PGDP probands evaluated between June 2015 and July 2020, querying our database for participant demographics, clinical characteristics, NGS results, and diagnostic and research findings. The three most common phenotypes among the entire studied cohort (n = 356) were immune system abnormalities (n = 105, 29%), syndromic or multisystem disease (n = 103, 29%), and cardiovascular system abnormalities (n = 62, 17%).

Seroprevalence of SARS-CoV-2 antibodies among blood donors in Québec: an update from a serial cross-sectional study.

Objectives: We previously estimated the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies following the first pandemic wave at 2.23% in Québec, Canada. Following the much bigger second wave in fall 2020 and early 2021, we estimated the seroprevalence of anti-SARS-CoV-2 in Québec during the first months of 2021.

Synthetic development of sugar amino acid oligomers towards novel podophyllotoxin analogues.

In this work, we have developed an approach for the synthesis of sugar amino acid oligomers based on the glucosamine scaffold. We found that the solid-phase approach was unsuccessful for the preparation of sugar amino acid oligomers and the limitation of the liquid-phase approach revolved around the low solubility of larger oligomers. Nevertheless, this strategy allowed the coupling of alkynylated carbohydrate amino acids with podophyllotoxin-bearing an azide functional group yielding novel podophyllotoxin analogues.

A glycan-based plasmonic sensor for prostate cancer diagnosis.

Prostate cancer affects thousands of men who undergo clinical screening tests every year. The main biomarker used for the diagnosis of prostate cancer, prostate specific antigen (PSA), presents limitations that justify investigating new biomarkers to improve reliability. Antibodies against the tumor-associated carbohydrate antigen (Tn), or TACA, develop early in carcinogenesis, making them an interesting alternative as a target for prostate cancer diagnostics.

SARS-CoV-2 seroprevalence among blood donors in Québec, and analysis of symptoms associated with seropositivity: a nested case-control study.

Objectives: A substantial proportion of individuals infected with SARS-CoV-2 do not experience noticeable symptoms typical of COVID-19. Our objectives were to evaluate the impact of the first wave of the pandemic in Québec by measuring SARS-CoV-2 antibody seroprevalence in a convenience sample of healthy blood donors and to study the association between seropositivity and the occurrence of COVID-19 symptoms.

Methods: The study design was a cross-sectional serological survey with a nested case-control study.

Polyfluoroglycoside Synthesis via Simple Alkylation of an Anomeric Hydroxyl Group: Access to Fluoroetoposide Analogues.

In this work, we have developed a new approach for the synthesis of fluoroglycoside analogues. This strategy used a simple alkylation protocol and allowed the installation of a simple aglyconic alkane with the β configuration. Moreover, the glycosylation of fluorinated glucoside analogues with 4'-demethylepipodophyllotoxin furnished novel fluoroetoposide analogues.

Major role of IgM in the neutralizing activity of convalescent plasma against SARS-CoV-2.

Characterization of the humoral response to SARS-CoV-2, the etiological agent of COVID-19, is essential to help control the infection. The neutralization activity of plasma from patients with COVID-19 decreases rapidly during the first weeks after recovery. However, the specific role of each immunoglobulin isotype in the overall neutralizing capacity is still not well understood.

Decline of Humoral Responses against SARS-CoV-2 Spike in Convalescent Individuals.

In the absence of effective vaccines and with limited therapeutic options, convalescent plasma is being collected across the globe for potential transfusion to coronavirus disease 2019 (COVID-19) patients. The therapy has been deemed safe, and several clinical trials assessing its efficacy are ongoing. While it remains to be formally proven, the presence of neutralizing antibodies is thought to play a positive role in the efficacy of this treatment.

Cross-Sectional Evaluation of Humoral Responses against SARS-CoV-2 Spike.

SARS-CoV-2 is responsible for the coronavirus disease 2019 (COVID-19) pandemic, infecting millions of people and causing hundreds of thousands of deaths. The Spike glycoproteins of SARS-CoV-2 mediate viral entry and are the main targets for neutralizing antibodies. Understanding the antibody response directed against SARS-CoV-2 is crucial for the development of vaccine, therapeutic, and public health interventions.

Adding polyvinylpyrrolidone to low level protein samples significantly improves peptide recovery in FASP digests: An inexpensive and simple modification to the FASP protocol.

Filter-aided sample preparation (FASP) remains a popular choice for proteomic sample preparation, particularly for its ability to produce a 'clean' peptide sample clear of large molecule contaminants. However, sample loss continues to be a problem particularly for sample inputs that contain less than ten micrograms of protein. Here, we describe that the simple addition of a polymer, polyvinylpyrrolidone-40 (PVP-40) to the protein sample prior to FASP digest significantly improves peptide recovery and identifications, especially with lower level sample inputs.

Waning of SARS-CoV-2 RBD antibodies in longitudinal convalescent plasma samples within 4 months after symptom onset.

There is a Commentary on this article in this issue.

Short-Term exposure of umbilical cord blood CD34+ cells to human platelet lysate and cytokines enhances engraftment.

Background: Intra bone marrow (IBM) injection has been proposed as a strategy to bypass homing inefficiencies associated with intravenous (IV) hematopoietic progenitor stem cell (HSPC) transplantation and thus increases the number of HSPC that engraft. Despite physical delivery into the bone marrow cavity, many donor cells are rapidly redistributed by vascular perfusion. Thus, the objective of our study was to evaluate the ability of human platelet lysates (hPL) to improve HSPC retention into the bone marrow and consequently to improve engraftment.

Daudi cell stroma: An alternative to dithiothreitol to resolve daratumumab interference in pretransfusion testing.

Unlabelled: Treatment of red blood cells with dithiothreitol (DTT) or trypsin effectively denatures CD38; however, this treatment damages other antigens, some of which are of clinical importance. Thus, other avenues to deplete daratumumab (DARA) from plasma samples should be explored.

Study Design And Methods: The Daudi B-cell line was found to express high levels of CD38 and was sonicated in a sonication buffer to achieve complete cell lysis.

Cross-sectional evaluation of humoral responses against SARS-CoV-2 Spike.

The SARS-CoV-2 virus is responsible for the current worldwide coronavirus disease 2019 (COVID-19) pandemic, infecting millions of people and causing hundreds of thousands of deaths. The Spike glycoprotein of SARS-CoV-2 mediates viral entry and is the main target for neutralizing antibodies. Understanding the antibody response directed against SARS-CoV-2 is crucial for the development of vaccine, therapeutic and public health interventions.

Synthesis of C-terminal glycopeptides via oxime resin aminolysis.

Natural glycopeptides have been shown to possess interesting biological activities. In this work, we have developed a general solid-phase approach to C-terminal glycopeptides. Taking advantage of oxime resin ester bond nucleophile susceptibility, we optimised the nucleophilic cleavage step with glycosylamines and demonstrated the generality and scope of this method.

Antigen Identification for Cell-Binding Antibodies Using Ligand-Directed Crosslinking and Biotin Transfer.

Panning approaches using antibody libraries often result in the isolation of antibodies that bind to cells through an unknown cellular receptor. Here, we describe a protocol that uses ligand-directed crosslinking with the aminooxy-sulfhydryl-biotin (ASB) trifunctional crosslinker followed by a proteomic analysis to identify the cellular receptors for orphan ligands. We describe the synthesis of the ASB crosslinker, labelling of the ligand with ASB, and cell binding of the labelled ligands.

Exploring the Chemistry of Non-sticky Sugars: Synthesis of Polyfluorinated Carbohydrate Analogues of d-Allopyranose.

There is a growing interest in the preparation of polyfluorinated carbohydrates. A limited number of fluorohexopyranosides have been used in biological investigations because of the synthetic challenge they present. Hence, we report the synthesis of fluorinated homodimer, fluorodisaccharides, C-terminal fluoroglycopeptides, lipoic acid fluoroglycoconjugate and trifluoroallopyranoside derivatives functionalized at C-6.