Project description:Objective: Production of pathogenic autoantibodies by self-reactive plasma cells (PC) is a hallmark of autoimmune diseases. Investigating the prevalence of PC in autoimmune disease and their relationship with known pathogenic pathways may increase our understanding of the role of PC in disease progression and treatment response. Methods: We developed a sensitive gene expression based method to overcome the challenges of measuring PC using flow cytometry. Whole genome microarray analysis of sorted cellular fractions identified a panel of genes, IGHA, IGJ, IGKC, IGKV, and TNFRSF17, expressed predominantly in PC. The sensitivity of the PC signature score created from the combined expression levels of these genes was assessed through ex vivo experiments with sorted cells. This PC gene expression signature was used for monitoring changes in PC levels following anti-CD19 therapy; evaluating the relationship between PC and other autoimmune disease-related genes; and estimating PC levels in affected blood and tissue from multiple autoimmune diseases. Results: The PC signature was highly sensitive and capable of detecting as few as 300 PCs. The PC signature was reduced over 90% in scleroderma patients following anti-CD19 treatment and this reduction was highly correlated (r = 0.77) with inhibition of collagen gene expression. Evaluation of multiple autoimmune diseases revealed 30-35% of lupus, rheumatoid arthritis, and scleroderma patients with increased PC levels. Conclusion: This newly developed PC signature provides a robust and accurate method to measure PC levels in the clinic. Our results highlight subsets of patients across multiple autoimmune diseases that may benefit from PC depleting therapy. To examine gene expression in purified cellular fractions, normal human blood was collected from 2 donors as per institutional policy. The granulocyte (CD15+), monocyte (CD14+), T cell (CD3+), B cell (Non-PC gated, CD19+), and PC (CD27++CD38++) fractions from peripheral blood were separated. White blood cells were washed with FACS buffer (PBS + 0.5%BSA + 2mM EDTA (Gibco)) and incubated with 20% heat-inactivated FBS for 10-15 minutes on ice. The following mAbs were added directly to the cells: CD15 (HI98); CD14 (M5E2), CD3 (UCHT1), CD27 (M-T271), CD38 (HB7), and DAPI (Molecular probes). Cells were sorted on a Becton Dickinson FACS Aria II flow cytometer. All sorted fractions were collected in FACS buffer, centrifuged, and the resulting cell pellet was suspended in RNA lysis buffer (Ambion).
Project description:Objective: Production of pathogenic autoantibodies by self-reactive plasma cells (PC) is a hallmark of autoimmune diseases. Investigating the prevalence of PC in autoimmune disease and their relationship with known pathogenic pathways may increase our understanding of the role of PC in disease progression and treatment response. Methods: We developed a sensitive gene expression based method to overcome the challenges of measuring PC using flow cytometry. Whole genome microarray analysis of sorted cellular fractions identified a panel of genes, IGHA, IGJ, IGKC, IGKV, and TNFRSF17, expressed predominantly in PC. The sensitivity of the PC signature score created from the combined expression levels of these genes was assessed through ex vivo experiments with sorted cells. This PC gene expression signature was used for monitoring changes in PC levels following anti-CD19 therapy; evaluating the relationship between PC and other autoimmune disease-related genes; and estimating PC levels in affected blood and tissue from multiple autoimmune diseases. Results: The PC signature was highly sensitive and capable of detecting as few as 300 PCs. The PC signature was reduced over 90% in scleroderma patients following anti-CD19 treatment and this reduction was highly correlated (r = 0.77) with inhibition of collagen gene expression. Evaluation of multiple autoimmune diseases revealed 30-35% of lupus, rheumatoid arthritis, and scleroderma patients with increased PC levels. Conclusion: This newly developed PC signature provides a robust and accurate method to measure PC levels in the clinic. Our results highlight subsets of patients across multiple autoimmune diseases that may benefit from PC depleting therapy. MI-CP200 is a Phase 1, randomized, double-blind, placebo-controlled study to evaluate the safety and tolerability of escalating single IV doses of MEDI-551 in adult subjects with scleroderma. In this study, 5 cohorts of subjects (n=25) received 1 of 5 single IV doses of MEDI-551 (0.1, 0.3, 1.0, 3.0, or 10.0 mg/kg) or placebo. Twenty-four healthy donor control samples are also included.
Project description:RNA microarray profiling analysis was performed on splenic B cell subsets: “IgD+CD27-” (naive B cells) and “IgD+CD27+” (MZB B cells) isolated from splenic samples of 6 adults
Project description:RNA microarray profiling analysis was performed on 2 different ex-vivo splenic B cell subsets: M-^SIgD+CD27+M-^T (marginal zone B cells) and switched memory M-^SIgG+CD27+M-^T cells, isolated from splenic samples of 4 children (from 4 to 6 yr of age), 3 adults and 3 (or 4) seniors of more than 75 yr.
Project description:Motivation: The B-cell receptor (BCR) performs essential functions for the adaptive immune system including recognition of pathogen-derived antigens. The vast repertoire and adaptive variation of BCR sequences due to V(D)J recombination and somatic hypermutation (SHM) necessitates single-cell characterization of BCR sequences. Single-cell RNA sequencing (scRNA-seq) presents the opportunity for simultaneous capture of paired BCR heavy and light chains and the transcriptomic signature. Results: We developed VDJPuzzle, a novel bioinformatic tool that reconstructs productive, full-length B-cell receptor sequences of both heavy and light chains. VDJPuzzle successfully reconstructed BCRs from 98.3% (n=117) human and 96.5% (n=200) murine B cells. The reconstructed BCRs were successfully validated with single-cell Sanger sequencing. Availability: VDJPuzzle is available at https://bitbucket.org/kirbyvisp/vdjpuzzle2
Project description:The B-cell receptor (BCR) enables individual B cells to identify diverse antigens, including bacterial and viral proteins. While advances in RNA-seq have enabled high throughput profiling of transcript expression in single cells, the unique task of assembling the full-length heavy and light chain sequences from single cell RNA-sequencing (scRNA-seq) in B cells has been largely unstudied. We developed a new software tool, BASIC, which allows investigators to use scRNA-seq for assembling BCR sequences at single cell level. To demonstrate the utility of our software, we subjected single B cells from a human donor to scRNA-seq, assembled the full-length heavy and the light chains, and experimentally confirmed these results by using single cell primer based nested PCRs and Sanger sequencing.
Project description:RNA microarray profiling analysis was performed on different ex-vivo human splenic B cell subsets (M-^SNaM-oveM-^T, marginal zone precursors or M-^SMZPM-^T, marginal zone B cells orM-^T MZBM-^T, M-^SMTG+CD45+M-^T cells) and on M-^Sp27M-^T cells, corresponding to the fraction of MZP cells that differentiated into CD27-expressing cells after culture on OP9-hDLL1 cells cultured with OP9-hDLL1 cells that differentiated into CD27-expressing cells
Project description:Neutrophils rapidly respond to inflammation and infection, but to which degree their functional trajectories after mobilization from the bone marrow can be shaped within the circulation remains vague. Phenotypic changes of circulating neutrophils caused by systemic inflammation are thought to result from several factors, including a “left shift” of the neutrophil compartment towards younger bone marrow-derived subsets. However, experimental limitations have so far hampered neutrophil research in human disease. Here, using innovative fixation and single-cell-based toolsets, we profile the human and murine neutrophil transcriptome and proteome during steady state and bacterial infection. We find that peripheral priming of circulating neutrophils leads to plastic shifts dominated by conserved upregulation of antimicrobial genes across neutrophil substates, facilitating pathogen containment. We show the TLR4/NF-κB-signaling dependent upregulation of canonical neutrophil activation markers like CD177/NB-1 during acute inflammation, resulting in functional shifts in vivo. Importantly, blocking de novo RNA synthesis in circulating neutrophils abrogates these plastic shifts and prevents the adaptation of antibacterial neutrophil programs by upregulation of distinct effector molecules upon infection. In summary, these data underline transcriptional plasticity as a relevant mechanism of functional neutrophil reprogramming during acute infection to foster bacterial containment within the circulation. This adds to the understanding of competing modes of adaptation to inflammatory challenges by the neutrophil compartment.
Project description:The pathogenesis of nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) and its relationship to other lymphomas are largely unknown. This is partly due to the technical challenge of analyzing its rare neoplastic L&H cells, which are dispersed in an abundant non-neoplastic cellular microenvironment. We performed a genome-wide expression study of microdissected lymphocytic and histiocytic (L&H) lymphoma cells in comparison to normal and other malignant B cells, which indicates a relationship of L&H cells to and/or origin from germinal center B cells at transition to memory B cells. L&H cells show a surprisingly high similarity to the tumor cells of T cell-rich B cell lymphoma and classical Hodgkin lymphoma, a partial loss of their B cell phenotype and deregulation of many apoptosis-regulators and putative oncogenes. Importantly, L&H cells are characterized by constitutive NF-κB activity and aberrant ERK signaling. Thus, these findings shed new light on the nature of L&H cells, revealed several novel pathogenetic mechanisms in NLPHL, and may help in differential diagnosis and lead to novel therapeutic strategies. Experiment Overall Design: Analysis of differential gene expression in primary human lymphoma cells of nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) in comparison with primary lymphoma cells of classical Hodgkin lymphoma cells and other B-non-Hodgkin lymphoma (B-NHL) samples and subsets of non-neoplastic B lymphocytes isolated from blood or tonsils. 67 gene expression profiles were analysed.