Citations

Abstract The use of natural killer (NK) cells for the treatment of solid tumors such as cholangiocarcinoma has been hindered by challenges related to cell production, persistence and trafficking, as well as by reduced efficacy within an immunosuppressive tumor microenvironment. Antitumor immunity can be reduced by the interaction of NK cell expressed programmed cell death protein 1 (PD1) with ligands on tumor and other cells within the tumor microenvironment. The antitumor effect of NK cells is enhanced in cells engineered to express a truncated PD1 without an intracellular domain. The cytolytic potential and therapeutic efficacy of extracellular vesicles (EVs) derived from human NK cells expressing truncated PD1 was evaluated as a cell-free therapeutic to overcome some limitations faced by cell therapies. We demonstrate the feasibility of efficient expansion, production and isolation of therapeutic vesicles from human NK cell lines and from engineered NK92 cells expressing truncated PD1. The cytotoxic efficacy of these therapeutic vesicles was validated in both monolayer tumor cell cultures and in multicellular tumor spheroids. Concomitant administration of gemcitabine upregulated NKG2D ligands on tumor cells and increased susceptibility to NK cell and to NK cell derived EV mediated killing. These findings position engineered NK cell derived-EVs as a scalable and promising cell-free immunotherapeutic for cholangiocarcinoma.

Key Points Activin A is implicated in profibrotic and prosenescent kidney injury and correlates with kidney injury markers in animals and humans. Follistatin, through activin A antagonism, reduces senescence burden, macrophage infiltration, and proinflammatory pathway activation in murine diabetic kidney disease. Follistatin and other antagonists of activin A signaling pathways may be promising, novel therapeutics for diabetic kidney disease. Background Circulating activin A, an inflammatory mediator implicated in profibrotic kidney injury and cellular senescence-induced adipose tissue dysfunction, is increased in human diabetic kidney disease (DKD) and directly correlates with kidney dysfunction. We tested the hypothesis that activin A increases kidney injury, senescent cell abundance, and macrophage infiltration in DKD and antagonism through follistatin (FS) therapy diminishes these effects. Methods An accelerated nephropathy type 2 diabetes (db/db) mouse model was generated by implantation of angiotensin II-loaded osmotic minipumps resulting in increased albuminuria and glomerular and tubular injury. Kidney repair effects of FS (5 µ g intraperitoneal; two doses) were assessed through markers of kidney injury, fibrosis, inflammation, cellular senescence, and macrophage infiltration. In vitro studies examined antiactivin effects of FS on high glucose-exposed human monocytes, renal fibroblasts, and renal tubule epithelial cells. Results Activin A antagonism with FS reduced senescence (p19), proinflammatory (including senescence-associated secretory phenotype), and profibrotic markers including activin A. FS improved kidney morphology, restored podocyte markers (nephrin and Wilms tumor-1), and reduced kidney injury biomarkers, albuminuria and kidney fibrosis. FS decreased kidney macrophage and leukocyte infiltration and absent in melanoma 2 inflammasome activation. FS seemed to suppress inflammation through the toll-like receptor-4/NF kappa-light-chain-enhancer of activated B cells pathway in vivo further supported in human macrophages in vitro . In addition, FS reduced hyperglycemia-induced renal fibroblast activation and renal tubule epithelial cell senescence in vitro . Conclusions Activin A is a mediator of kidney injury through macrophage-associated inflammation in murine DKD. FS acts through senomorphic activities which inhibit profibrotic, proinflammatory, and prosenescence signaling by activin A. Hence, antiactivin targeting may aid in the development of a promising, novel therapeutic for DKD.

AbstractThe Society for Cardiovascular Angiography and Interventions (SCAI) Think Tank is a collaborative venture that brings together interventional cardiologists, administrative partners, and select members of the cardiovascular industry community annually for high‐level field‐wide discussions. The 2021 Think Tank was organized into four parallel sessions reflective of the field of interventional cardiology: (a) coronary intervention, (b) endovascular medicine, (c) structural heart disease, and (d) congenital heart disease. Each session was moderated by a senior content expert and co‐moderated by a member of SCAI's Emerging Leader Mentorship program. This document presents the proceedings to the wider cardiovascular community in order to enhance participation in this discussion, create additional dialog from a broader base, and thereby aid SCAI, the industry community and external stakeholders in developing specific action items to move these areas forward.

X-linked reticulate pigmentary disorder (XLPDR, Mendelian Inheritance in Man #301220) is a rare syndrome characterized by recurrent infections and sterile multiorgan inflammation. The syndrome is caused by an intronic mutation in POLA1, the gene encoding the catalytic subunit of DNA polymerase-α (Pol-α), which is responsible for Okazaki fragment synthesis during DNA replication. Reduced POLA1 expression in this condition triggers spontaneous type I interferon expression, which can be linked to the autoinflammatory manifestations of the disease. However, the history of recurrent infections in this syndrome is as yet unexplained. Here we report that patients with XLPDR have reduced NK cell cytotoxic activity and decreased numbers of NK cells, particularly differentiated, stage V, cells (CD3 – CD56 dim ). This phenotype is reminiscent of hypomorphic mutations in MCM4 , which encodes a component of the minichromosome maintenance (MCM) helicase complex that is functionally linked to Pol-α during the DNA replication process. We find that POLA1 deficiency leads to MCM4 depletion and that both can impair NK cell natural cytotoxicity and show that this is due to a defect in lytic granule polarization. Altogether, our study provides mechanistic connections between Pol-α and the MCM complex and demonstrates their relevance in NK cell function.