Project description:The recent SARS-CoV-2 omicron variant presented significant challenges to the global effort to counter the pandemic. SARS-CoV-2 is predicted to remain prevalent in the coming months, making the ability to identify SARS-CoV-2 variants imperative in understanding and controlling the pandemic. The predominant variant discovery method, genome sequencing, is time-consuming, insensitive, and expensive. Liquid chromatography-mass spectrometry (LC-MS) offers an exciting alternative detection modality provided that variant-containing peptide markers become well-established. This study demonstrates the potential to establish SARS-CoV-2 peptide markers by examining amino-acid variant-containing tryptic peptides, their MS fragmentation intensities, and their detection sensitivity in MS experiments. We have synthesized model tryptic peptides from of SARS-CoV-2 variants beta, gamma, delta, and omicron and evaluated their signal intensity, HCD spectra, and reverse phase retention time.
Project description:This experiment aims to profile polyclonal antibody binding profiles in serum from vaccinated animals relative to antibody function in a virus neutralization assay. Rabbits received three vaccinations with a DNA vaccine encoding the spike protein of the SARS-CoV-2 index strain. Serum samples were selected based on a three-tier (low, intermediate, and high) capacity to cross-neutralize SARS-CoV-2 strains with known neutralization resistance. Following normalization of total anti-spike IgG levels, serum of each animal (n=3) were evaluated for antibody binding to 10mer cyclic constrained peptides spanning the entire spike protein and regions with known SARS-CoV-2 variant of concern spike mutations.
Project description:The SARS-CoV-2 Delta variant is more contagious than WT and causes severe symptoms.To understand the elevated fusogenicity of Delta, we used LC-MS/MS to characterize the site specific N-linked glycan of spike protein in SARS-CoV-2 Delta variant virions.The glycan analysis revealed increased oligomannose-type glycosylation of native Delta spike over that of the Wuhan-Hu-1 spike.
Project description:Diverse severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants have emerged since the beginning of COVID-19 pandemic. We investigated the immunological and pathological characteristics of SARS-CoV-2 beta variant of concern (VOC) compared to the ancestral strain. To investigate a broad spectrum of immunological responses and to determine the underlying mechanisms of differentially expressed cytokines, we analyzed the whole transcriptome of lung homogenates from SARS-CoV-2 ancestral strain- and beta variant-infected mice at 4 and 6 dpi.