Project description:This study aims to understand the characteristics and diversification of Dengue specific immunoglobulin repertoires after different immunization strategies in mouse. We propose two different immunization strategies in dengue vaccine development. One is tetravalent strategy, which pre-mixed four serotype dengue DNA vaccine and administrated four times. The other one is sequential strategy, which sequentially administrated four time, each serotype vaccine for each dose as sequences of Den1, Den2, Den3 and Den4.
Project description:This study aims to under the characteristics and diversitification of Dengue speicific immunoglobulin repertoires after different immunization strategies in mouse. We propose two different immunization strategies in dengue vaccine development, one is repeated strategy, which DENV1 virus and administrated three times. The other one is epitope-decreased sequential strategy, which sequetially administrated DENV1 virus, DENV1 E protein and DENV1 E protein domain III subunit.
Project description:We used 454 sequencing to assess the repertoire of B cell subsets from bone marrow, spleen, and small intestinal lamina propria from two mouse strains. We used a RAG2-GFP reporter mouse strain (129Sve background) to isolate CD19+ RAG2+ B lineage cells from bone marrow and small intestinal lamina propria and total splenic B cells. We used 5' RACE to amplify cDNA libraries using primers specific for the mu constant region of IgH and the Ig kappa constant region. We also used this technique to analyze total B cell libraries from Swiss Webster germ-free mice to compare to littermate controls that were cohoused with regular specific pathogen free (SPF) mice for 7 days. Examination of the Ig kappa repertoire and IgH repertoire in RAG2+ bone marrow B lineage cells compared to RAG2+ small intestinal lamina propria B lineage cells or total splenic B cells. There are 8 (Ig kappa) or 4 (IgH) independent experiments comparing repertoires in RAG2-GFP mice. Each experiment in RAG2-GFP+ mice consisted of a pool of 8-12 mice. There are 3 experiments comparing germ-free to colonized mouse total B cell repertoires, each consisting of one mouse per condition.
Project description:Developing B lymphocytes undergo V(D)J recombination to assemble germline V, D, and J gene segments into exons that encode the antigen-binding variable region of immunoglobulin (Ig) heavy (H) and light (L) chains. IgH and IgL chains associate to form the B cell receptor (BCR), which upon antigen binding activates B cells to secrete BCR as an antibody. Each of the huge number of clonally independent B cells expresses a unique set of IgH and IgL variable regions. Ability of V(D)J recombination to generate vast primary B cell repertoires results from combinatorial assortment of large numbers of different V, D, and J segments, coupled with diversification of the junctions between them to generate the complementary determining region 3 (CDR3) for antigen contact. Approaches to evaluate in depth the content of primary antibody repertoires and, ultimately, to study how they are further molded by secondary mutation and affinity maturation processes are of great importance to the B cell development, vaccine, and antibody fields. We now describe an unbiased, sensitive, and readily accessible assay, referred to as HTGTS repertoire sequencing (HTGTS-Rep-seq), to quantify antibody repertoires. HTGTS-Rep-seq quantitatively identifies the vast majority of IgH and IgL V(D)J exons, including their unique CDR3 sequences, from progenitor and mature mouse B lineage cells via the use of specific J primers. HTGTS-Rep-seq also accurately quantifies DJH intermediates and V(D)J exons in either productive or non-productive configurations. HTGTS-Rep-seq should be useful for studies of human samples, including clonal B-cell expansions and also for following antibody affinity maturation processes. We employed high-throughput genome-wide translocation sequencing adapted repertoire sequencing (HTGTS-Rep-seq) to study antibody repertoires. For HTGTS-Rep-seq libraries, we utilize bait coding ends of J segments to identify, in unbiased fashion, mouse IgH DJH repertoires [processed tlx files] along with both productive and non-productive IgH V(D)J repertoires from both pro-B and peripheral B cells [processed xls files of samples 1-18, 21-51]. Similarly, we also identify mouse productive and non-productive Igk repertoires from peripheral B cells [processed xls files of samples 19,20,52-57].
Project description:Dengue virus infection can result in severe symptoms including shock and hemorrhage, but an understanding of the molecular correlates of disease severity is lacking. Bulk transcriptomics on blood samples are difficult to interpret because the blood is composed of different cell types that may react differently to virus infection. Dengue virus RNA can be detected in human plasma, however identifying the cells carrying dengue virus through the bloodstream in vivo has proven challenging. Here we used our recently developed viscRNA-Seq approach to profile transcriptomes of thousands of single blood peripheral mononuclear cells from 6 human subjects with dengue fever and severe dengue, as well as to characterize the cell types associated with dengue virus in the human blood. We found that although no bulk transcriptome marker for severe dengue exists, the expression of MX2 in naive B cells, of CD163 in CD14+/CD16+ monocytes and of other genes in specific cell types is highly predictive for severe dengue. We detected virus-associated cells in the blood of two severe dengue patients with high viral load and discovered the majority of these to be B cells expressing germline IgM or IgD immunoglobulin chains and naive markers but also showing signs of activation and expression of CD69, CXCR4, and other surface receptors. In bystander B cells we detected signs of strong immune activation, parallel hypersomatic evolution and, in one severe degue subject, an anomalously large clone of highly mutated, IgG1 plasmablasts that could be reactive to dengue virus. This study presents a high-resolution molecular exploration into dengue virus infection in humans and can be generalized to any RNA virus.
Project description:To in-depth analyze the anti-SARS-CoV-2 humoral response and find elements that can lead or prevent acute respiratory distress syndrome (ARDS), we dissected the multiple layers of B cell responses by NGS immunoglobulin repertoires on RNA template from peripheral blood cell of severe COVID-19 patients.