Project description:Although the genetic basis of autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) has been uncovered, the cellular and molecular mechanisms characterizing this rare neurodegenerative disease are still under investigation, and no cure has yet been developed. In this study, we analyzed proteomics data obtained using the SomaLogic technology, comparing cell lysates from ARSACS patients and from a SACS KO SH-SY5Y neuroblastoma cell model. Single-stranded deoxyoligonucleotides, selected in vitro from large random libraries, bound and quantified molecular targets related to the neuroinflammation signaling pathway and to neuronal development. Changes in protein levels were further analyzed by bioinformatics and network approaches to identify biomarkers of ARSACS and functional pathways impaired in the disease. We identified novel significantly dysregulated biological processes related to neuroinflammation, synaptogenesis and engulfment of cells in patients and in KO cells compared with controls. Among the differential expressed proteins found in this work, we identified several proteins encoded by genes already known to be mutated in other forms of neurodegeneration. This finding suggests that common dysfunctional networks could be therapeutic targets for future investigations.
Project description:Plasma protein expression patterns can be used as prognostic biomarkers in various types of cancer. We aimed to identify a protein-based signature for distant metastatic risk assessment in patients with locoregionally advanced nasopharyngeal carcinoma (LA-NPC).
Project description:The immunomodulatory mycobacterial surface antigen lipoarabinomannan (LAM) with its immunogenic glycan component arabinomannan (AM) facilitates Mycobacterium tuberculosis’ (Mtb) escape from the host’s immune response. Some but not all antibodies against AM can protect against TB. To better understand which of AM’s structures to target, we must first identify the spectrum of its epitopes. Through isolating and characterizing a panel of novel human mAbs with binding to distinct AM OS motifs, we further defined the glycan epitope structures, identified a new epitope, and determined their differences among mycobacterial strains.
Project description:The immunomodulatory mycobacterial surface antigen lipoarabinomannan (LAM) with its immunogenic glycan component arabinomannan (AM) facilitates Mycobacterium tuberculosis’ (Mtb) escape from the host’s immune response. Some but not all antibodies against AM can protect against TB. To better understand which of AM’s structures to target, we must first identify the spectrum of its epitopes. We here used synthetic AM oligosaccharide motifs to deplete sera from subjects along the spectrum of Mtb infection. Performing cluster analysis, we were able to predict AM’s immunogenic structures and delineate how antibody reactivity to them is influenced by Mtb infection states.
Project description:Investigation of whole genome-derived tiled peptide arrays to identify epitopes associated with autoantibody reactivity in NSCLC as a potential means for early detection. Arrays consisted of 2,781,902 tiled peptides representing 20,193 proteins encoded in the human genome. The detailed analysis in this study is further described in Yan et al. Whole genome-derived tiled peptide arrays detect pre-diagnostic autoantibody signatures in non-small cell lung cancer. Cancer Res. 2019 Feb 5. pii: canres.1536.2018
Project description:3 BRAF/MEK inhibitor resistance melanoma cells were treated with PAK inhibitor PF3758309 for 48 hr, the cell lysis were analyzed by RPPA profiling by protein array (RPPA)
Project description:Mice were immunized with either formalin fixed Influenza A/PR/8/34 (Killed PR8), the 2006-2007 seasonal influenza vaccine, the 2007-2008 seasonal influenza vaccine, a sublethal infection (live PR8) or mock immunized (PBS). Array data was used to distinguish the immunogens from each other and predict which of the three inactivated vaccines would be protective against A/PR/8/34 challenge.
Project description:Epitope mapping studies aim to identify the binding sites of antibody-antigen interactions to enhance the development of vaccines, diagnostics and immunotherapeutic compounds. However, mapping is a laborious process employing time- and resource-consuming ‘wet bench’ techniques or epitope prediction software that are still in their infancy. For polymorphic antigens, another challenge is characterizing cross-reactivity between epitopes, teasing out distinctions between broadly cross-reactive responses, limited cross-reactions among variants and the truly type-specific responses. A refined understanding of cross-reactive antibody binding could guide the selection of the most informative subsets of variants for diagnostics and multivalent subunit vaccines. We explored the antibody binding reactivity of sera from human patients and Peromyscus leucopus rodents infected with Borrelia burgdorferi to the polymorphic outer surface protein C (OspC), an attractive candidate antigen for vaccine and improved diagnostics for Lyme disease. We constructed a protein microarray displaying 23 natural variants of OspC and quantified the degree of cross-reactive antibody binding between all pairs of variants, using Pearson correlation calculated on the reactivity values using three independent transforms of the raw data: (1) logarithmic, (2) rank, and (3) binary indicators. We observed that the global amino acid sequence identity between OspC pairs was a poor predictor of cross-reactive antibody binding. Then we asked if specific regions of the protein would better explain the observed cross-reactive binding and performed in silico screening of the linear sequence and 3-dimensional structure of OspC. This analysis pointed to the C-terminal helix of the structure as a major determinant of type-specific cross-reactive antibody binding. We developed bioinformatics methods to systematically analyze the relationship between local sequence/structure variation and cross-reactive antibody binding patterns among variants of a polymorphic antigen, and this method can be applied to other polymorphic antigens for which immune response data is available for multiple variants.
Project description:Numerous leucine-rich repeat kinase 2 mutations identified throughout the protein are associated with Parkinson disease, however the activating G2019S kinase domain mutation is currently regarded as the most common cause of familial and sporadic forms of this disorder. Despite studies demonstrating the prominent role that its kinase activity plays in the pathobiology of leucine-rich repeat kinase 2, few substrates have been identified and only a subset of these have been linked to disease. Therefore, we utilized protein microarrays to screen over 9,000 human proteins in an unbiased radiometric assay for potential targets of the kinase.