Human brain tumor stem cells have been enriched using antibodies against the surface protein CD133. An antibody recognizing CD133 also served to isolate normal neural stem cells from fetal human brain, suggesting a possible lineage relationship between normal neural and brain tumor stem cells. Whether CD133-positive brain tumor stem cells can be derived from CD133-positive neural stem or progenitor cells still requires direct experimental evidence, and an important step toward such investigations is the identification and characterization of normal CD133-presenting cells in neurogenic regions of the embryonic and adult brain. Here, we present evidence that CD133 is a marker for embryonic neural stem cells, an intermediate radial glial/ependymal cell type in the early postnatal stage, and for ependymal cells in the adult brain, but not for neurogenic astrocytes in the adult subventricular zone. Our findings suggest two principal possibilities for the origin of brain tumor stem cells: a derivation from CD133-expressing cells, which are normally not present in the adult brain (embryonic neural stem cells and an early postnatal intermediate radial glial/ependymal cell type), or from CD133-positive ependymal cells in the adult brain, which are, however, generally regarded as postmitotic. Alternatively, brain tumor stem cells could be derived from proliferative but CD133-negative neurogenic astrocytes in the adult brain. In the latter case, brain tumor development would involve the production of CD133. [Cancer Res 2007;67(12):5727-36]

Key Points Single-cell gene expression analysis reveals CML stem cell heterogeneity and changes imposed by TKI therapy. A subpopulation with primitive, quiescent signature and increased survival to therapy can be high-purity captured as CD45RA−cKIT−CD26+.

SUMMARYAbnormal CD4/CD8 ratios and T-cell function have previously been shown in patients with B-chronic lymphocytic leukaemia (B-CLL). We have demonstrated that CD4 1 T cells containing both serine esterase and perforin (PF) are increased in the blood of these patients. Using flow cytometry, we have shown that the CD4 1 PF 1 cells were CD57 1 but lacked expression of CD28, suggesting a mature population. The same phenotype in CD8 1 T cells is characteristic of mature cytotoxic T cells. However, in contrast to the CD8 1 T cells, the CD4 1 T cells were more frequently CD45RO positive than CD45RA positive, indicating prior antigen experience. In contrast, this population lacked expression of either CD69 or HLA-DR, arguing that they were not activated or that they are an abnormal population of T cells. Their constitutive cytokine levels showed them mainly to contain IL4 and not IFNg, suggesting a Th2 phenotype. The role of the CD4 1 PF 1 T-cell population is at present uncertain. However, this potentially cytotoxic T-cell population could contribute both to enhancing survival of the B-CLL tumour cells through production of IL4, and to the immunodeficient state frequently seen in patients with this tumour, independent of drug treatment.

We identified a subset of T CD4 FoxP3 cells, i.e., aTregs that were correlated to aGvHD development, and demonstrated plasticity of the nonTreg population to provide phenotypic aTregs. This could have both a predictive clinical relevance in inflammatory conditions as well as support a rationale for development of cell targeted therapy. © 2016 International Clinical Cytometry Society.

Supplementary Movie from CD133 Is Not Present on Neurogenic Astrocytes in the Adult Subventricular Zone, but on Embryonic Neural Stem Cells, Ependymal Cells, and Glioblastoma Cells