Project description:Bacterial binding to host receptors underlies both commensalism and pathogenesis. Many streptococci adhere to protein-attached carbohydrates expressed on cell surfaces using Siglec-like binding regions (SLBRs). The precise glycan repertoire recognized may dictate whether the organism is a strict commensal versus a pathogen. However, it is currently not clear what drives receptor selectivity. Here, we use five representative SLBRs and identify regions of the receptor binding site that are hypervariable in sequence and structure. We show that these regions control the identity of the preferred carbohydrate ligand using chimeragenesis and single amino acid substitutions. We further evaluate how the identity of the preferred ligand affects the interaction with glycoprotein receptors in human saliva and plasma samples. As point mutations can change the preferred human receptor, these studies suggest how streptococci may adapt to changes in the environmental glycan repertoire.
Project description:This SuperSeries is composed of the following subset Series: GSE11944: Mucosal Glycan Foraging Enhances the Fitness and Transmission of a Saccharolytic Human Distal Gut Symbiont GSE11953: Mucosal Glycan Foraging Enhances the Fitness and Transmission of a Saccharolytic Human Distal Gut Symbiont: ECF mutant GSE11962: Growth of B. thetaiotaomicron on purified host mucosal glycans and glycan fragments Refer to individual Series
Project description:Human induced pluripotent stem cells (iPSC)-derived cells are often heterogeneous, posing challenges for disease modeling and cell therapy. We previously developed single-cell glycan and RNA sequencing (scGR-seq) to analyze the glycome and transcriptome simultaneously. Here, we applied scGR-seq to examine heterogeneous populations of human iPSC-derived neurons. We identified four subpopulations: mature neurons, immature neurons, undifferentiated neural progenitor cells (undiffNPCs), and mesenchymal cells (MCs). Lectin binding patterns indicated high α1,3-fucose expression in undiffNPCs. MCs exhibited strong binding of a poly-LacNAc-recognizing lectin (rLSLN) and high expression of B3GNT2, a poly-LacNAc synthetic enzyme. Pseudotime analysis revealed that a subpopulation of NPCs acquired mesenchymal features and differentiated into MCs. Immunocytochemistry confirmed the specific detection of undiffNPCs and MCs using anti-Lewis X (α1,3-fucosylated glycan) antibodies and rLSLN. Beyond identifying cell heterogeneity, scGR-seq enables the discovery of glycan markers and detection probes for iPSC-derived cells, aiding in their further cell processing and manipulation.
Project description:Human antibody responses to AM/LAM are heterogenous and knowledge of reactivity to specific glycan epitopes at the monoclonal level is limited. Using novel glycan arrays, we characterized very high affinity monoclonal antibodies to AM/LAM, determined these mAbs are non-competing, and recognized distinct glycan epitopes. distinct from other anti-AM/LAM mAbs reported.
Project description:Increasing evidence suggests that antibodies (Abs) can have protective roles in M. tuberculosis (Mtb) infection but knowledge of the most relevant protective antigens and epitopes in humans is limited. Using novel glycan arrays, we establish that human serum IgG induced against the M. tuberculosis (Mtb) capsular polysacharide arabinomannan (AM) in natural Mtb infection is highly heterogeneous in its binding specificity and differs in both its reactivity to oligosaccharide (OS) motifs within AM and its functions between BCG vaccination and/or controlled (latent) versus uncontrolled (TB) M. tuberculosis infection. We show that anti-AM IgG from asymptomatic but not diseased individuals is protective, and provide data suggesting a role of IgG2 and specific AM oligosaccharides. Filling a gap in the current knowledge of protective antigens in humans, our human data support the key role of the M. tuberculosis surface glycan AM and suggest the importance of targeting specific glycan epitopes within AM in antibody-mediated immunity against TB.
Project description:Purpose: This study uses a high-throughput glycan microarray to develop a novel method to assign ABO blood type. The method will then be applied to samples from patients treated with PROSTVAC to determine if blood type correlates with survival Results: Many blood group A and B antigens correlate with blood type. Blood typing is best achieved using a combination of 10 signals Conclusion: ABO blood type can be determined with greater than 97% accuracy using only 4 microliters of serum.
Project description:Analysis of expression of genes involved in glycan and glycan-binding molecule synthesis in dendritic cells. Gene expression patterns for unstimulated dendritic cells, macrophages, and monocytes were compared. Also, gene expression patterns for dendritic cells and macrophages stimulated with LPS for 4 and 18 hours were compared to unstimulated cells. Three replicate samples of RNA were taken from human cells, one sample per donor. Samples were prepared and hybridized to the GLYCOv3 array.