The omicron variant of SARS-CoV-2 drove broadly increased seroprevalence in a public university setting.

Omicron is the comparatively most transmissible and contagious variant of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). We conducted a seroprevalence study from March 1-3, 2022, to investigate the seroprevalence of SARS-CoV-2 antibodies among individuals aged 18 years and older after the Omicron outbreak. The seroprevalence of anti-receptor binding domain (RBD) antibodies was found to be 96.

Nanoparticle-Supported, Rapid, Digital Quantification of Neutralizing Antibodies Against SARS-CoV-2 Variants.

The measurement of neutralizing immune responses to viral infection is essential, given the heterogeneity of human immunity and the emergence of new virus strains. However, neutralizing antibody (nAb) assays often require high-level biosafety containment, sophisticated instrumentation, and long detection times. Here, as a proof-of-principle, we designed a nanoparticle-supported, rapid, electronic detection (NasRED) assay to assess the neutralizing potency of monoclonal antibodies (mAbs) against SARS-CoV-2.

Quantitative assessment of multiple pathogen exposure and immune dynamics at scale.

Serology reveals exposure to pathogens, as well as the state of autoimmune and other clinical conditions. It is used to evaluate individuals and their histories and as a public health tool to track epidemics. Employing a variety of formats, studies nearly always perform serology by testing response to only one or a few antigens.

Serological survey to estimate SARS-CoV-2 infection and antibody seroprevalence at a large public university: A cross-sectional study.

Objective: This study investigated the seroprevalence of SARS-CoV-2 antibodies among adults over 18 years.

Design: Prospective cohort study.

Settings: A large public university.

New use for CETSA: monitoring innate immune receptor stability via post-translational modification by OGT.

O-GlcNAcylation is a dynamic and functionally diverse post-translational modification shown to affect thousands of proteins, including the innate immune receptor nucleotide-binding oligomerization domain-containing protein 2 (Nod2). Mutations of Nod2 (R702W, G908R and 1007 fs) are associated with Crohn's disease and have lower stabilities compared to wild type. Cycloheximide (CHX)-chase half-life assays have been used to show that O-GlcNAcylation increases the stability and response of both wild type and Crohn's variant Nod2, R702W.

Crohn's Disease Variants of Nod2 Are Stabilized by the Critical Contact Region of Hsp70.

Nod2 is a cytosolic, innate immune receptor responsible for binding to bacterial cell wall fragments such as muramyl dipeptide (MDP). Upon binding, subsequent downstream activation of the NF-κB pathway leads to an immune response. Nod2 mutations are correlated with an increased susceptibility to Crohn's disease (CD) and ultimately result in a misregulated immune response.

Metabolic labelling of the carbohydrate core in bacterial peptidoglycan and its applications.

Bacterial cells are surrounded by a polymer known as peptidoglycan (PG), which protects the cell from changes in osmotic pressure and small molecule insults. A component of this material, N-acetyl-muramic acid (NAM), serves as a core structural element for innate immune recognition of PG fragments. We report the synthesis of modifiable NAM carbohydrate derivatives and the installation of these building blocks into the backbone of Gram-positive and Gram-negative bacterial PG utilizing metabolic cell wall recycling and biosynthetic machineries.

Redefining the Defensive Line: Critical Components of the Innate Immune System.

The human body harbors over a trillion microorganisms; the innate immune system is charged with a tremendous task: to recognize "the needle in the haystack" or, in other words, to sense the pathogen in this milieu. In this viewpoint, three recent discoveries in the field of innate immunity are discussed, highlighting how in each case multiple disciplines worked together to expand the elements of the innate immune system.

Identification and biological consequences of the O-GlcNAc modification of the human innate immune receptor, Nod2.

Nucleotide-binding oligomerization domain 2 (Nod2) is an intracellular receptor that can sense the bacterial peptidoglycan component, muramyl dipeptide. Upon activation, Nod2 induces the production of various inflammatory molecules such as cytokines and chemokines. Genetic linkage analysis identified and revealed three major mutations in Nod2 that are associated with the development of Crohn's disease.

Peptidoglycan Modifications Tune the Stability and Function of the Innate Immune Receptor Nod2.

Natural modifications of peptidoglycan modulate the innate immune response. Peptidoglycan derivatives activate this response via the intracellular innate immune receptor, Nod2. To probe how these modifications alter the response, a novel and efficient carbohydrate synthesis was developed to allow for late-stage modification of the amine at the 2-position.