Introduction of human erythropoietin receptor complementary DNA by retrovirus-mediated gene transfer into murine embryonic stem cells enhances erythropoiesis in developing embryoid bodies

To evaluate the role of the erythropoietin (Epo) receptor (R) in erythropoiesis in more primitive stem cells, we assessed the influence of retrovirus-mediated gene transfer of human (h) EpoR complementary DNA (cDNA) into murine embryonic stem (ES) cells on erythroid differentiation of these cells. The hEpoR cDNA was efficiently transduced into ES cells, forming hEpoR that stably expressed ES (ES-hEpoR) cells. Expression of hEpoR cDNA was confirmed in ES-hEpoR cells by reverse transcriptase-polymerase chain reaction and Northern blot analysis. Colony assays demonstrated that definitive erythroid and primitive erythroid colonies were significantly increased from ES-hEpoR cells, when compared with mock virus-transduced ES (ES-Neo) cells, during the time course of differentiation induced by withdrawal of leukemia inhibitory factor, in either the presence or the absence of Epo. Multipotential colony-forming units (CFU-Mix) were also increased in ES-hEpoR cells at different stages of differentiation, but no changes were detected for CFU-granulocyte-macrophage colonies (CFU-GM). Time course studies by Northern blot analysis demonstrated elevated levels of expression of beta-H1 and beta-Major globin genes in embryoid bodies derived from ES-hEpoR cells stimulated with Epo, when compared with similar expression from ES-Neo cells. Expression of the GATA-1 gene was enhanced in ES-hEpoR cells, when compared with ES-Neo cells, beginning immediately after initiation of the cultures until 8 days of differentiation. These data indicate that primitive and definitive erythropoiesis in differentiating embryoid bodies can be enhanced by retrovirus-mediated gene transfer of an hEpoR gene. Biol Blood Marrow Transplant 2000;6(4):395-407

Hemodynamic changes after transcatheter aortic valve implantation during sequential follow-ups in patients with bicuspid aortic valve compared with tricuspid aortic valve

Background: To investigate the individual sequential hemodynamic changes after transcatheter aortic valve implantation (TAVI), especially for patients with bicuspid aortic valve (BAV), in comparison with tricuspid aortic valve (TAV). Methods: The study population comprised 85 patients with severe aortic stenosis who underwent TAVI for BAV (n = 49) or TAV (n = 36) with at least two serial echocardiographic follow-ups. Doppler echocardiography was scheduled to be performed at discharge and 1, 3, 6 months and 1 year after the procedure. D peak transvalvular velocities and D mean transvalvular gradients were calculated as the difference at follow-up time points and discharge. Paravalvular leak (PVL) was assessed as another indicator for prosthesis performance. Results: Comparisons between patients with BAV and TAV revealed similar gradient performances (1.00 [–2.00, 2.00] vs. 1.00 [–0.25, 5.00] mm Hg, p = 0.57 at 1 month; –0.71 ± 7.52 vs. 1.55 ± 3.97 mm Hg, p = 0.21 at 3 months; 0.96 ± 7.81 vs. 1.53 ± 5.85 mm Hg, p = 0.79 at 6 months; 1.00 [–0.50, 2.25] vs. 3.00 [–0.50, 7.50] mm Hg, p = 0.07 at 1 year). Moreover, the incidence of ≥ mild PVL was not significantly different in patients with BAV and TAV during follow-up (34.88% vs. 19.35%, p = 0.14 at 1 month; 45.83% vs. 27.27%, p = 0.19 at 3 months; 30.00% vs. 23.53%, p = 0.89 at 6 months; 30.00% vs. 17.65%, p = 0.56 at 1 year). Conclusions: TAVI is effective and applicable in BAV anatomy with sustained and acceptable mid- -term prosthesis hemodynamic performance. (Cardiol J 2017; 24, 4: 350–357

Emergent Schr\"{o}dinger cat states during superradiant phase transitions

Superradiant phase transitions (SPTs) are important for understanding light-matter interactions at the quantum level [1, 2], and play a central role in criticality-enhanced quantum sensing [3]. So far, SPTs have been observed in driven-dissipative systems [4-9], but the emergent light fields did not show any nonclassical characteristic due to the presence of strong dissipation. Here we report an experimental demonstration of the SPT featuring the emergence of a highly nonclassical photonic field, realized with a resonator coupled to a superconducting qubit, implementing the quantum Rabi model [10, 11]. We fully characterize the light-matter state by Wigner matrix tomography. The measured matrix elements exhibit quantum interference intrinsic of a photonic Schr\"{o}dinger cat state [12], and reveal light-matter entanglement. Besides their fundamental importance, these hitherto unobserved emergent quantum phenomena are useful for quantum metrology and fault-tolerant quantum computation.Comment: 19 pages, 14 figures, 2 table

31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two

Background The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd. Methods We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background. Results First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001). Conclusions In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival

MLL repression domain interacts with histone deacetylases, the polycomb group proteins HPC2 and BMI-1, and the corepressor C-terminal-binding protein

The MLL (mixed-lineage leukemia) gene is involved in many chromosomal translocations associated with acute myeloid and lymphoid leukemia. We previously identified a transcriptional repression domain in MLL, which contains a region with homology to DNA methyltransferase. In chromosomal translocations, the MLL repression domain is retained in the leukemogenic fusion protein and is required for transforming activity of MLL fusion proteins. We explored the mechanism of action of the MLL repression domain. Histone deacetylase 1 interacts with the MLL repression domain, partially mediating its activity; binding of Cyp33 to the adjacent MLL-PHD domain potentiates this binding. Because the MLL repression domain activity was only partially relieved with the histone deacetylase inhibitor trichostatin A, we explored other protein interactions with this domain. Polycomb group proteins HPC2 and BMI-1 and the corepressor C-terminal-binding protein also bind the MLL repression domain. Expression of exogenous BMI-1 potentiates MLL repression domain activity. Functional antagonism between Mll and Bmi-1 has been shown genetically in murine knockout models for Mll and Bmi-1. Our new data suggest a model whereby recruitment of BMI-1 to the MLL protein may be able to modulate its function. Furthermore, repression mediated by histone deacetylases and that mediated by polycomb group proteins may act either independently or together for MLL function in vivo