DeltahGHR, a novel biosafe cell surface-labeling molecule for analysis and selection of genetically transduced human cells

Human cord blood CD34+Pax-5+ B-cell progenitors: single-cell analyses of their gene expression profiles

Circulating CD34(+) cells are used in reparative medicine as a stem cell source, but they contain cells already committed to different lineages. Many think that B-cell progenitors (BCPs) are confined to bone marrow (BM) niches until they differentiate into B cells and that they do not circulate in blood. The prevailing convention is that BCP transit a CD34(+)CD19(-)10(+) early-B-->CD34(+)CD19(+)CD10(+) B-cell progenitor (pro-B)-->CD34(-)CD19(+)CD10(+) B-cell precursor (pre-B) differentiation pathway within BM. However, populations of CD34(+)CD10(+) and CD34(+)CD19(+) cells circulate in adult peripheral blood and neonatal umbilical cord blood (CB) that are operationally taken as BCPs on the basis of their phenotypes, although they have not been submitted to a systematic characterization of their gene expression profiles. Here, conventional CD34(+)CD19(+)CD10(+) and novel CD34(+)CD19(+)CD10(-) BCP populations are characterized in CB by single-cell sorting and multiplex analyses of gene expression patterns. Circulating BCP are Pax-5(+) cells that span the early-B, pro-B, and pre-B developmental stages, defined by the profiles of rearranged V-D-J(H), CD79, VpreB, recombination activating gene (RAG), and terminal deoxynucleotidyl transferase (TdT) expression. Contrary to the expectation, circulating CD34(+)CD19(-)CD10(+) cells are essentially devoid of Pax-5(+) BCP. Interestingly, the novel CD34(+)CD19(+)CD10(-) BCP appears to be the normal counterpart of circulating preleukemic BCPs that undergo chromosomal translocations in utero months or years before their promotion into infant acute lymphoblastic B-cell leukemia after secondary postnatal mutations. The results underscore the power of single-cell analyses to characterize the gene expression profiles in a minor population of rare cells, which has broad implications in biomedicine.

Hepatic fibrosis--role of hepatic stellate cell activation

Hepatic fibrosis is a reversible wound healing response characterized by accumulation of extracellular matrix (ECM), or "scar," that follows chronic but not self-limited liver disease. The ECM components in fibrotic liver are similar regardless of the underlying cause. Activation of hepatic stellate cells is the central event in hepatic fibrosis. These perisinusoidal cells orchestrate an array of changes including degradation of the normal ECM of liver, deposition of scar molecules, vascular and organ contraction, and release of cytokines. Not only is hepatic fibrosis reversible, but it is also increasingly clear that cirrhosis may be reversible as well. The exact stage at which fibrosis/cirrhosis becomes truly irreversible is not known. Antifibrotic therapies will soon be a clinical reality. Emerging therapies will be targeted to those patients with reversible disease. The paradigm of stellate cell activation provides an important framework for defining therapeutic targets.