Project description:PurposeAdenosine deaminase (ADA) deficiency causes severe combined immunodeficiency (SCID) through an accumulation of toxic metabolites within lymphocytes. Recently, ADA deficiency has been successfully treated using lentiviral-transduced autologous CD34+ cells carrying the ADA gene. T and B cell function appears to be fully restored, but in many patients' B cell numbers remain low, and assessments of the immunoglobulin heavy (IgHV) repertoire following gene therapy are lacking.MethodsWe performed deep sequencing of IgHV repertoire in peripheral blood lymphocytes from a child following lentivirus-based gene therapy for ADA deficiency and compared to the IgHV repertoire in healthy infants and adults.ResultsAfter gene therapy, Ig diversity increased over time as evidenced by V, D, and J gene usage, N-additions, CDR3 length, extent of somatic hypermutation, and Ig class switching. There was the emergence of predominant IgHM, IgHG, and IgHA CDR3 lengths after gene therapy indicating successful oligoclonal expansion in response to antigens. This provides proof of concept for the feasibility and utility of molecular monitoring in following B cell reconstitution following gene therapy for ADA deficiency.ConclusionBased on deep sequencing, gene therapy resulted in an IgHV repertoire with molecular diversity similar to healthy infants.
Project description:We applied high-throughput sequencing of the IGH repertoire in peripheral blood and bone marrow (BM) of a primary immunodeficiency patient. We obtained 325994 IGH sequences from the BM sample and 72597 IGH sequences from the peripheral blood. After comparing with IMGT/GENE-DB database (http://www.imgt.org), we found obviously increased CDR3 clonality in the patient BM as compared to his peripheral blood. Furthermore, the frequency of IgG transcripts in the patient BM was higher than that in the peripheral blood while the frequency of IgM transcripts was similar.
Project description:A diverse antibody repertoire is formed through the rearrangement of V, D, and J segments at the immunoglobulin heavy chain (Igh) loci. The C57BL/6 murine Igh locus has over 100 functional VH gene segments that can recombine to a rearranged DJH. While the non-random usage of VH genes is well documented, it is not clear what elements determine recombination frequency. To answer this question we conducted deep sequencing of 5M-bM-^@M-^Y-RACE products of the Igh repertoire in pro-B cells, amplified in an unbiased manner. ChIP-seq results for several histone modifications and RNA polymerase II binding, RNA-seq for sense and antisense non-coding germline transcripts, and proximity to CTCF and Rad21 sites were compared to the usage of individual V genes. Computational analyses assessed the relative importance of these various accessibility elements. These elements divide the Igh locus into four epigenetically and transcriptionally distinct domains, and our computational analyses reveal different regulatory mechanisms for each region. Proximal V genes are relatively devoid of active histone marks and non-coding RNA in general, but having a CTCF site near their RSS is critical, suggesting that position near the base of the chromatin loops is important for rearrangement. In contrast, distal V genes have high levels of histone marks and non-coding RNA, which may compensate for their poorer RSS and for being distant from CTCF sites. Thus, the Igh locus has evolved a complex system for the regulation of V(D)J rearrangement that is different for of each the four domains that comprise this locus. For the ChIP-seq, input and immunoprecipitated DNA was given to The Scripps DNA Array Facility, where it was prepared for massively parallel sequencing on Illumina HiSeq2000.
Project description:Gene transfer into HSCs by gammaretroviral vectors (RV) is an effective treatment for inherited blood disorders, although potentially limited by the risk of insertional mutagenesis. We evaluated the genomic impact of RV integration in T-lymphocytes from adenosine deaminase (ADA)-Severe combined immunodeficiency (SCID) patients 10 to 30 months after infusion of autologous, genetically-corrected CD34+ cells. Expression profiling on ex vivo T-cell bulk population revealed no difference with respect to healthy controls. To assess the effect of vector integration on gene expression at the single cell level, primary T-cell clones were isolated from two patients. T-cell clones harboured either one or two vector copies per cell and displayed partial to full correction of ADA expression, purine metabolism and TCR-driven functions. Analysis of retroviral integration sites (RIS) indicated a high diversity in T-cell origin, consistent with the polyclonal TCR-Vbeta repertoire. Quantitative transcript analysis of 120 genes within a 200kb-window around RIS showed modest (2.8- to 5.2-fold) disregulation of 5.8% genes in 18.6% of the T-cell clones compared to controls. Nonetheless, affected clones maintained a stable phenotype and normal functions in vitro. These results confirm that RV-mediated gene transfer for ADA-SCID is safe, and provide crucial information for the development of future gene therapy protocols. Global gene expression profiling was performed on CD4+ and CD8+ T-cell subsets purified ex vivo from three ADA-SCID patients at different times after gene therapy. The microarray analysis showed a substantial overlap with the expression patterns of T-cells from controls, indicating the absence of gross abnormalities in the development and function of T-cells derived from genetically corrected hematopoietic stem/progenitor cells. Experiment Overall Design: Transcript profiling was carried out in CD4+ and CD8+ T-cells purified with immunomagnetic beads (Miltenyi Biotec, Germany) from the peripheral blood lymphocytes of ADA-SCID patients (Pt1, 3 and 4) 10-30 months after autologous transplantation with genetically corrected CD34+ cells. At the indicated time points, the percentage of vector-positive T-cells by qPCR was >75%. Transcript profiles were determined using the Affymetrix HG-U133A microarray and compared to those of age-matched healthy controls (n=4; C1, C2, C3, C4).
Project description:The immunoglobulin heavy-chain (Igh) locus undergoes large-scale contraction in pro-B cells, which facilitates VH-DJH recombination by juxtaposing distal VH genes next to the DJH- rearranged gene segment in the proximal Igh domain. By high-resolution mapping of long-range interactions, we now demonstrate that an array of local interaction domains establishes the three- dimensional structure of the extended Igh locus in lymphoid progenitors and thymocytes. In pro- B cells, these local domains engage in long-range interactions across the entire Igh locus, which depend on the transcription factors Pax5, YY1 and CTCF. The large VH gene cluster thereby undergoes flexible long-range interactions with the more rigidly structured 3M-bM-^@M-^Y proximal domain, which ensures that all VH genes can participate with similar probability in VH-DJH recombination to generate a diverse antibody repertoire. Notably, these long-range interactions appear to be an intrinsic feature of the VH gene cluster, as they are still generated upon mutation of the EM-NM-< enhancer, IGCR1 insulator or 3M-bM-^@M-^Y regulatory region present in the 3M-bM-^@M-^Y proximal Igh domain. 4C sequencing from mutliple celltypes with multiple viewpoints; uneven number of replicates ChIP-Seq
Project description:Analysis of the antibody repertoire composition is now possible using VDJ-seq. We used this recently developed method for unbiased amplification from genomic DNA (gDNA) to directly compare the Igh repertoire of C57Bl/6 (WT) and NE1-/- pro-B cells. We find that a group of contiguous proximal and intermediate VH genes are under-utilized in V->DJ rearrangement in the absence of NE1 revealing a NE1 zone of influence. We report the VH gene usage profile from WT and NE1-/- primary pro-B cells from the VDJ-seq data.
Project description:A diverse antibody repertoire is formed through the rearrangement of V, D, and J segments at the immunoglobulin heavy chain (Igh) loci. The C57BL/6 murine Igh locus has over 100 functional VH gene segments that can recombine to a rearranged DJH. While the non-random usage of VH genes is well documented, it is not clear what elements determine recombination frequency. To answer this question we conducted deep sequencing of 5’-RACE products of the Igh repertoire in pro-B cells, amplified in an unbiased manner. ChIP-seq results for several histone modifications and RNA polymerase II binding, RNA-seq for sense and antisense non-coding germline transcripts, and proximity to CTCF and Rad21 sites were compared to the usage of individual V genes. Computational analyses assessed the relative importance of these various accessibility elements. These elements divide the Igh locus into four epigenetically and transcriptionally distinct domains, and our computational analyses reveal different regulatory mechanisms for each region. Proximal V genes are relatively devoid of active histone marks and non-coding RNA in general, but having a CTCF site near their RSS is critical, suggesting that position near the base of the chromatin loops is important for rearrangement. In contrast, distal V genes have high levels of histone marks and non-coding RNA, which may compensate for their poorer RSS and for being distant from CTCF sites. Thus, the Igh locus has evolved a complex system for the regulation of V(D)J rearrangement that is different for of each the four domains that comprise this locus.
Project description:A diverse antibody repertoire is formed through the rearrangement of V, D, and J segments at the immunoglobulin heavy chain (Igh) loci. The C57BL/6 murine Igh locus has over 100 functional VH gene segments that can recombine to a rearranged DJH. While the non-random usage of VH genes is well documented, it is not clear what elements determine recombination frequency. To answer this question we conducted deep sequencing of 5M-bM-^@M-^Y-RACE products of the Igh repertoire in pro-B cells, amplified in an unbiased manner. ChIP-seq results for several histone modifications and RNA polymerase II binding, RNA-seq for sense and antisense non-coding germline transcripts, and proximity to CTCF and Rad21 sites were compared to the usage of individual V genes. Computational analyses assessed the relative importance of these various accessibility elements. These elements divide the Igh locus into four epigenetically and transcriptionally distinct domains, and our computational analyses reveal different regulatory mechanisms for each region. Proximal V genes are relatively devoid of active histone marks and non-coding RNA in general, but having a CTCF site near their RSS is critical, suggesting that position near the base of the chromatin loops is important for rearrangement. In contrast, distal V genes have high levels of histone marks and non-coding RNA, which may compensate for their poorer RSS and for being distant from CTCF sites. Thus, the Igh locus has evolved a complex system for the regulation of V(D)J rearrangement that is different for of each the four domains that comprise this locus. RNA was extracted from C57BL/6 RAG-/- pro-B cells using TrizolM-BM-. (Life Technologies Corp., Carlsbad CA) and genomic DNA was eliminated using the genomic DNA wipeout buffer in the QuantiTect Reverse transcription kit (QIAGEN). A final purification of the RNA was performed with the RNeasy kit from QIAGEN. For each sample, 100 ng of total RNA was used to make RNASeq libraries using the NuGEN Encore Complete DR kits following manufacturer's recommended protocols. Sequencing libraries were gel purified to ensure insert sizes were larger than 100 bp in length and sequenced on an Ilumina HiSeq2000 for 100 bases plus 7 bases for indexing.
Project description:Purpose: IGH sequencing has revolutionized analysis of structural and functional signatures of B cell clonality. The goals of this study are to compare IGH repertoire of splenic B cells before and after knockdown of long isoform of PRLR. Methods: After amplifying the IGH repertoire of splenic B cells using PCR primers for VHJ558 variable and Cμ constant regions. For next generation sequencing (NGS), a TrueSeq library was prepared by adapter ligation to full-length products and sequenced on the MiSeq Illumina 2x150 bp platform. Results: In this project, Unique nucleotide sequences were identified, their abundances were calculated, and their complementary determining region 3 (CDR3) length, CDR3 spectrum, VDJ usage, and diversity were analyzed using the International Immunogenetics Information System (IMGT) HighV-QUEST software. Controls are included C3,C4,C5,C7,C8 and C9. LFPRLR SMO treated mice samples are: A3,A4,A5,A6,A7 and A8