Project description:A key mechanism of tumor resistance to immune cells is mediated by expression of peptide-loaded HLA-E in tumor cells, which suppresses natural killer (NK) cell activity via ligation of the NK inhibitory receptor CD94/NKG2A. To bypass HLA-E inhibition, we developed a way to generate highly functional NK cells lacking NKG2A. Constructs containing a single-chain variable fragment derived from an anti-NKG2A antibody were linked to endoplasmic reticulum-retention domains. After retroviral transduction in human peripheral blood NK cells, these NKG2A Protein Expression Blockers (PEBLs) abrogated NKG2A expression. The resulting NKG2Anull NK cells had higher cytotoxicity against HLA-E-expressing tumor cells.
Project description:Oxidized phospholipids (OxPL) are pro-inflammatory and pro-atherogenic, but their roles in non-alcoholic steatohepatitis (NASH) are unknown. Here, we show that OxPL accumulate in human and murine NASH. Using a transgenic mouse that expresses a functional single chain variable fragment of E06, a natural antibody that neutralizes OxPL, we demonstrate the casual role of OxPL in NASH. Targeting OxPL in hyperlipidemic Ldlr-/- mice decreased multiple aspects of NASH, including steatosis, inflammation, fibrosis, hepatocyte death and progression to hepatocellular carcinoma. Mechanistically, we found that OxPL promote ROS accumulation to induce mitochondrial dysfunction in hepatocytes. Neutralizing OxPL in AMLN diet-fed Ldlr-/- mice reduced oxidative stress, improved hepatic and adipose tissue mitochondrial function and fatty acid oxidation. Since neutralizing OxPL also protects against atherogenesis, targeting OxPL may be an effective therapeutic strategy for both NASH and atherosclerosis.
Project description:We engineered a new m6A editing system consisting of GCN4 (SunTag)-dCas13b, anti-GCN4 single chain variable fragment (scFv)-FTO or ALKBH5-GBI and sgRNA to provide an applicable method to remove m6A modification at specific loci.
Project description:We used single cell RNA sequencing (scRNAseq) to compare gene expression in human T cells following stimulation with antibodies directed against a CD3 subunit (CD3ε) versus the TCRβ chain variable (V) domain
Project description:A semi-automated method for enrichment of groups of peptides using individual or multiplexed combinations of single chain variable fragment antibodies was developed and tested in plasma.
2024-08-28 | PXD047828 | Pride
Project description:Transgenic hookworm secretes anti-tetrodotoxin human single chain antibody
Project description:Recombinant proteins containing disulfide bonds, like antibody fragments, are usually produced in the periplasm of E. coli, because in this compartment of the E. coli cell the formation of disulfide bonds is catalyzed. A recombinant protein is targeted to the periplasm with the help of an N-terminally fused signal sequence, which is clipped off from the recombinant protein upon translocation across the cytoplasmic membrane. The single-chain variable antibody fragment BL1 N-terminally fused to the DsbA signal sequence was produced in the E. coli Lemo21(DE3) recombinant protein production strain at conditions non-optimal (0 µM L-rhamnose) and optimal (500 µM L-rhamnose) for the production of the scFv BL1 in the periplasm. Lemo21(DE3) cells not producing a recombinant protein were used as a reference.
Project description:The human immunoglobulin heavy chain (IGH) locus is exceptionally polymorphic with high allelic diversity of variable (V) genes and structural variation affecting large regions of the locus. Thus, our germline IGHV gene and allele content is highly personal, which may influence how we respond to infections and vaccinations. Here, we coupled individualized IGHV genotyping with the isolation of monoclonal antibodies against the SARS-CoV-2 spike, focusing on the IGHV1-69 and IGHV3-30 group of genes, which were over-represented in spike-specific B cells. These genes are characterized by both allelic and copy number variations, making them ideal for expanding our understanding of inter-individual differences in antigen-specific antibody responses. We found that for the IGHV1-69*20-using CAB-I47 antibody, the allele usage was critical as germline reversion to other, highly similar, IGHV1-69 alleles abolished the neutralizing activity. Our results demonstrate that as little as single nucleotide differences between different alleles can greatly influence the biological response.
Project description:Production of an ostrich-derived phage display library to capture the ostrich-derived single-chain variable fragment (scFv) antibodies
Project description:Aminoacyl tRNA synthetases (aaRSs) have long been viewed as mere housekeeping proteins and have therefore often been overlooked in drug discovery. However, recent findings have revealed that many aaRSs have non-canonical functions and several of them have been linked to autoimmune diseases, cancer and neurological disorders. In order to study these proteins further, recombinant high-affinity antibodies have been generated to a selection of thirteen cytoplasmic and one mitochondrial aaRSs. Selected domains of these proteins were produced recombinantly in Escherichia coli and used as antigens in phage display selections using a synthetic human single-chain fragment variable (scFv) library. All targets yielded large sets of antibody candidates that were validated through a panel of binding assays against the purified antigen. Furthermore, the top performing binders were tested in immunoprecipitation followed by mass spectrometry (IP-MS) for their ability to capture the endogenous protein from mammalian cell lysates. Interestingly, for antibodies targeting individual members of the multi-tRNA synthetase complex (MSC), we were able to detect all members of the complex, co-immunoprecipitating with the target, in several cell types. The functionality of a sub-set of binders for each target was also confirmed in immunofluorescence. To conclude, we have created an open source resource, in the form of high quality recombinant proteins and antibodies to accelerate and empower future research of the role of aaRSs in health and disease.