Immune Shielding of Human Heart Valves: A Proof-of-Concept Study of HLA-Targeting Therapy for Transplantations.

Children born with defective heart valves require multiple donor valve replacements throughout life, because these cannot grow and can cause early failure through immune degeneration. This study tests the lentiviral delivery of viral immune evasion genes US2 and human serpin 9 to shield human heart valves from immune rejection. The results show we can efficiently down-regulate human leukocyte antigen expression in heart valve cells and in intact heart valve tissue resulting in decreased activity of a human leukocyte antigen-reactive CD8+ T-cell clone without inducing cytotoxicity.

Single-cell analysis of human fetal epicardium reveals its cellular composition and identifies CRIP1 as a modulator of EMT.

The epicardium plays an essential role in cardiogenesis by providing cardiac cell types and paracrine cues to the developing myocardium. The human adult epicardium is quiescent, but recapitulation of developmental features may contribute to adult cardiac repair. The cell fate of epicardial cells is proposed to be determined by the developmental persistence of specific subpopulations.

Restructuring of titanium oxide overlayers over nickel nanoparticles during catalysis.

Reducible supports can affect the performance of metal catalysts by the formation of suboxide overlayers upon reduction, a process referred to as the strong metal-support interaction (SMSI). A combination of operando electron microscopy and vibrational spectroscopy revealed that thin TiO overlayers formed on nickel/titanium dioxide catalysts during 400°C reduction were completely removed under carbon dioxide hydrogenation conditions. Conversely, after 600°C reduction, exposure to carbon dioxide hydrogenation reaction conditions led to only partial reexposure of nickel, forming interfacial sites in contact with TiO and favoring carbon-carbon coupling by providing a carbon species reservoir.