Functional and molecular integrity of cardiomyocytes (CMs) derived from induced pluripotent stem (iPS) cells is essential for their use in tissue repair, disease modelling and drug screening. In this ...study we compared global transcriptomes of beating clusters (BCs) microdissected from differentiating human iPS cells and embryonic stem (ES) cells.
Hierarchical clustering and principal component analysis revealed that iPS-BCs and ES-BCs cluster together, are similarly enriched for cardiospecific genes and differ in expression of only 1.9% of present transcripts. Similarly, sarcomeric organization, electrophysiological properties and calcium handling of iPS-CMs were indistinguishable from those of ES-CMs. Gene ontology analysis revealed that among 204 genes that were upregulated in iPS-BCs vs ES-BCs the processes related to extracellular matrix, cell adhesion and tissue development were overrepresented. Interestingly, 47 of 106 genes that were upregulated in undifferentiated iPS vs ES cells remained enriched in iPS-BCs vs ES-BCs. Most of these genes were found to be highly expressed in fibroblasts used for reprogramming and 34% overlapped with the recently reported iPS cell-enriched genes.
These data suggest that iPS-BCs are transcriptionally highly similar to ES-BCs. However, iPS-BCs appear to share some somatic cell signature with undifferentiated iPS cells. Thus, iPS-BCs may not be perfectly identical to ES-BCs. These minor differences in the expression profiles may occur due to differential cellular composition of iPS-BCs and ES-BCs, due to retention of some genetic profile of somatic cells in differentiated iPS cell-derivatives, or both.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Regulatory T cells (T(reg) cells) are increased in context of malignancies and their expansion can be correlated with higher disease burden and decreased survival. Initially, interleukin 2 (IL-2) has ...been used as T-cell growth factor in clinical vaccination trials. In murine models, however, a role of IL-2 in development, differentiation, homeostasis, and function of T(reg) cells was established. In IL-2 treated cancer patients a further T(reg)-cell expansion was described, yet, the mechanism of expansion is still elusive. Here we report that functional T(reg) cells of a naïve phenotype--as determined by CCR7 and CD45RA expression--are significantly expanded in colorectal cancer patients. Treatment of 15 UICC stage IV colorectal cancer patients with IL-2 in a phase I/II peptide vaccination trial further enlarges the already increased naïve T(reg)-cell pool. Higher frequencies of T-cell receptor excision circles in naïve T(reg) cells indicate IL-2 dependent thymic generation of naïve T(reg) cells as a mechanism leading to increased frequencies of T(reg) cells post IL-2 treatment in cancer patients. This finding could be confirmed in naïve murine T(reg) cells after IL-2 administration. These results point to a more complex regulation of T(reg) cells in context of IL-2 administration. Future strategies therefore might aim at combining IL-2 therapy with novel strategies to circumvent expansion and differentiation of naïve T(reg) cells.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Blood-based transcriptomics: leukemias and beyond Staratschek-Jox, Andrea; Classen, Sabine; Gaarz, Andrea ...
Expert review of molecular diagnostics,
20/4/1/, Letnik:
9, Številka:
3
Journal Article
Recenzirano
In 1999, Golub et al. proposed for the first time microarray-based transcriptional profiling to be used as a new technology for the differential diagnosis of acute myeloid leukemias and acute ...lymphocytic leukemias. This very preliminary study sparked great enthusiasm beyond the leukemias. Over the last 10 years, numerous studies addressed the use of gene expression profiling of peripheral blood from patients with malignancies, infectious diseases, autoimmunity and even cardiovascular diseases. Despite this great effort, no single test has yet been established using microarray-based transcriptional profiling of peripheral blood. Here we highlight the advances in the field of blood transcriptomics during the last 10 years and also critically discuss the issues that need to be resolved before blood transcriptomics will become part of daily diagnostics in the leukemias, as well as in other diseases showing involvement of peripheral blood.
The function of the IgM B‐cell receptor (BCR) is dependent on intact signaling of the co‐receptors Igα and Igβ, both of which contain a cytoplasmic tail bearing an immunoreceptor tyrosine‐based ...activation motif. We have previously demonstrated that the cytoplasmic tail of the IgG1 BCR can partially compensate for the loss of the signaling moiety of Igα. Here, we show that unlike Igα, Igβ signaling is indispensable for the development and function of IgG1‐expressing B cells. Deletion of the cytoplasmic signaling tail of Igβ compromised the survival and proliferation not only of IgM+ B cells but also of IgG1‐expressing B cells. In the absence of the signaling tail of Igβ, the transcription levels of the antiapoptotic gene bcl‐xl and the cell‐cycle gene ccnd2 were reduced, consistent with the observed defects in survival and proliferation. These results demonstrate functional differences between Igα and Igβ in the transduction of IgG1 BCR signal.
The B cell receptor comprises membrane‐bound immunoglobulin and a dimer of Ig super family signal transducers Igα and Igβ, which initiates BCR signaling through immune receptor tyrosine activation motifs (ITAMs). Here, we show that IgG1 BCR can partially compensate for the loss of the signaling moiety of Igα, but not of Igβ.
The function of the IgM B-cell receptor (BCR) is dependent on intact signaling of the co-receptors Igalpha and Igbeta, both of which contain a cytoplasmic tail bearing an immunoreceptor ...tyrosine-based activation motif. We have previously demonstrated that the cytoplasmic tail of the IgG1 BCR can partially compensate for the loss of the signaling moiety of Igalpha. Here, we show that unlike Igalpha, Igbeta signaling is indispensable for the development and function of IgG1-expressing B cells. Deletion of the cytoplasmic signaling tail of Igbeta compromised the survival and proliferation not only of IgM+ B cells but also of IgG1-expressing B cells. In the absence of the signaling tail of Igbeta, the transcription levels of the antiapoptotic gene bcl-xl and the cell-cycle gene ccnd2 were reduced, consistent with the observed defects in survival and proliferation. These results demonstrate functional differences between Igalpha and Igbeta in the transduction of IgG1 BCR signal.
The function of the IgM B-cell receptor (BCR) is dependent on intact signaling of the co-receptors Igalpha and Igbeta, both of which contain a cytoplasmic tail bearing an immunoreceptor ...tyrosine-based activation motif. We have previously demonstrated that the cytoplasmic tail of the IgG1 BCR can partially compensate for the loss of the signaling moiety of Igalpha. Here, we show that unlike Igalpha, Igbeta signaling is indispensable for the development and function of IgG1-expressing B cells. Deletion of the cytoplasmic signaling tail of Igbeta compromised the survival and proliferation not only of IgM+ B cells but also of IgG1-expressing B cells. In the absence of the signaling tail of Igbeta, the transcription levels of the antiapoptotic gene bcl-xl and the cell-cycle gene ccnd2 were reduced, consistent with the observed defects in survival and proliferation. These results demonstrate functional differences between Igalpha and Igbeta in the transduction of IgG1 BCR signal.
Regulatory T cells (T(reg) cells) are essential for self-tolerance and immune homeostasis. Lack of effector T cell (T(eff) cell) function and gain of suppressive activity by T(reg) cells are ...dependent on the transcriptional program induced by Foxp3. Here we report that repression of SATB1, a genome organizer that regulates chromatin structure and gene expression, was crucial for the phenotype and function of T(reg) cells. Foxp3, acting as a transcriptional repressor, directly suppressed the SATB1 locus and indirectly suppressed it through the induction of microRNAs that bound the SATB1 3' untranslated region. Release of SATB1 from the control of Foxp3 in T(reg) cells caused loss of suppressive function, establishment of transcriptional T(eff) cell programs and induction of T(eff) cell cytokines. Our data support the proposal that inhibition of SATB1-mediated modulation of global chromatin remodeling is pivotal for maintaining T(reg) cell functionality.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We describe a mouse strain in which B cell development relies either on the expression of membrane-bound immunoglobulin (Ig) gamma1 or mu heavy chains. Progenitor cells expressing gamma1 chains from ...the beginning generate a peripheral B cell compartment of normal size with all subsets, but a partial block is seen at the pro- to pre-B cell transition. Accordingly, gamma1-driven B cell development is disfavored in competition with developing B cells expressing a wild-type (WT) IgH locus. However, the mutant B cells display a long half-life and accumulate in the mature B cell compartment, and even though partial truncation of the Ig alpha cytoplasmic tail compromises their development, it does not affect their maintenance, as it does in WT cells. IgG1-expressing B cells showed an enhanced Ca(2+) response upon B cell receptor cross-linking, which was not due to a lack of inhibition by CD22. The enhanced Ca(2+) response was also observed in mature B cells that had been switched from IgM to IgG1 expression in vivo. Collectively, these results suggest that the gamma1 chain can exert a unique signaling function that can partially replace that of the Ig alpha/beta heterodimer in B cell maintenance and may contribute to memory B cell physiology.
Immune tolerance is a central mechanism counteracting tumor-specific immunity and preventing effective anticancer immunotherapy. Induction of tolerance requires a specific environment in which ...tolerogenic dendritic cells (DCs) play an essential role deviating the immune response away from effective immunity. It was recently shown that maturation of DCs in the presence of PGE2 results in upregulation of indoleamine 2,3-dioxygenase (IDO) providing a potential mechanism for the development of DC-mediated Tcell tolerance. Here, we extend these findings, demonstrating a concomitant induction of IDO and secretion of soluble CD25 after DC maturation in the presence of PGE2. While maturation of DCs induced IDO expression on transcriptional level, only integration of PGE2 signaling led to up-regulation of functional IDO protein as well as significant expression of cell-surface and soluble CD25 protein. As a consequence, T-cell proliferation and cytokine production were significantly inhibited, which was mediated mainly by IDO-induced tryptophan depletion. Of importance, we demonstrate that different carcinoma entities associated with elevated levels of PGE2 coexpress CD25 and IDO in peritumoral dendritic cells, suggesting that PGE2 might influence IDO expression in human DCs in the tumor environment. We therefore suggest PGE2 to be a mediator of early events during induction of immune tolerance in cancer. (Blood. 2006;108:228-237)
The onset and structure of compositional convection in a rotating system are investigated experimentally. A vertically oriented cylindrical annulus filled with NH4Cl‐H2O solution is cooled from the ...bottom and can be rotated about its axis at rates ranging up to 10.5 rad s−1, corresponding to Ekman numbers down to 7.5 × 10−6. The Coriolis force has a strong effect on the structure of plumes above the mush‐liquid interface. Helical motion of the conduit, which is weakly developed in the non‐rotating case, is amplified by Coriolis forces that twist the plume conduits to lie nearly horizontally. This results in secondary plumes (or blobs) that rise from the sub‐horizontal primary plume conduits. This new instability could be an efficient mechanism for producing small‐scale flow in the form of buoyant blobs that ascend through the polar regions of the outer core.
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