Journal: Molecular Therapy. Methods & Clinical Development
Article Title: Harnessing DNA barcoding to enhance and sustain polyclonality in gene-edited hematopoietic stem cells
doi: 10.1016/j.omtm.2025.101615
Figure Lengend Snippet: Establishment and analysis of barcode library composition, diversity, and clonal distribution in in vitro culture and in vivo in post-transplant mice populations (A) Schematic representation of barcode library in the therapeutic donor: Top: AAV coRPK scheme. Middle: Zoom of variable and non-variable sequences. Bottom: Barcode library composition indicating N: T, A, C, G, and S: G and C, showing all possible combinations. (B) Top: scheme of the editing protocol for HSPCs. After purifying HSPCs, cells were pre-stimulated for 48 h. Following this pre-stimulation period, cells underwent electroporation and transduction with the appropriate virus. The transduction process lasted for 48 h. Subsequently, cells were washed and prepared for further analysis. Bottom: Media use for in vitro culture of human hematopoietic stem cells. Abbreviations: SFEM II StemSpan (P/S, penicillin/streptomycin; SCF, Stem Cell Factor; TPO, thrombopoietin; Flt3, FMS-like tyrosine kinase 3 ligand; IL-6, interleukin 6; IL-3, interleukin 3.) (C) Number and lineage distribution of colony forming units (CFUs) at different BC-AAV MOI. Smooth red indicates erythroid colonies (BFU-E), smooth blue indicates granulo-macrophage colonies (CFU-GM), mixed red and blue stripes denote myelo-erythroid mixed colonies (CFU-GEMM). (D) Percentage of gene integration in CFUs at different BC-AAV MOI, analyzed by in-out PCR. (E) Unique barcode sequences within the total population at different MOIs. (F) Top 10 more represented clones in relation to the entire population at day 14 of culture. Each bar in the graph represents a CB with an MOI. Within each bar, the groups represent the abundance of specific clones in relation to the total population. Each color represents a distinct clone within the bar. (G) Total number of clones within CD45 + human population in transplanted mice relative to 50,000 reads. (H) Shannon diversity index of human CD45 + cells at MOI 2000. (I) Abundance of the top 10 clones per mouse. (J) Dominance of the most prevalence clone in the BM of each mouse. (K) Representation of the top 10 major clones in relation to the entire population. Each bar in the graph represents an individual mouse. Within each bar, the groups represent the abundance of specific clones in relation to the total population, with each color representing a distinct clone within the bar. The boxplots show the median, range (from minimum to maximum values), and quartiles of the data distribution. ∗: p < 0.05; ∗∗: p < 0.01; ∗∗∗: p < 0.001.
Article Snippet: Purified CD34 + cells were obtained by immunoselection with the CD34 Micro-Bead kit (MACS; Miltenyi Biotech).
Techniques: In Vitro, In Vivo, Electroporation, Transduction, Virus, Clone Assay