Although treatment with the glucocorticoid-induced tumor necrosis factor receptor-related protein (GITR) agonistic antibody (DTA-1) has shown antitumor activity in various tumor models, the underlying mechanism is not fully understood. Here, we demonstrate that interleukin (IL)-21-producing follicular helper T (Tfh) cells play a crucial role in DTA-1-induced tumor inhibition. The administration of DTA-1 increased IL21 expression by Tfh cells in an antigen-specific manner, and this activation led to enhanced antitumor cytotoxic T lymphocyte (CTL) activity. Mice treated with an antibody that neutralizes the IL21 receptor exhibited decreased antitumor activity when treated with DTA-1. Tumor growth inhibition by DTA-1 was abrogated in Bcl6fl/flCd4Cre mice, which are genetically deficient in Tfh cells. IL4 was required for optimal induction of IL21-expressing Tfh cells by GITR costimulation and c-Maf mediated this pathway. Thus, our findings identify GITR costimulation as an inducer of IL21-expressing Tfh cells and provide a mechanism for the antitumor activity of GITR agonism. Copyright ©2020, American Association for Cancer Research.Metabolic reprogramming is critical for the polarization and function of tumor associated macrophages (TAMs) and hepatocarcinogenesis, but how this reprogramming occurs is unknown. Here, we showed that receptor-interacting protein kinase 3 (RIPK3), a central factor in necroptosis, is downregulated in hepatocellular carcinoma (HCC)-associated macrophages, which correlated with tumorigenesis and enhanced the accumulation and polarization of M2 TAM. Mechanistically, RIPK3 deficiency in TAMs reduced reactive oxygen species (ROS) and significantly inhibited caspase1-mediated cleavage of peroxisome proliferator-activated receptors (PPARs). These effects enabled PPAR activation and facilitated fatty acid metabolism, including fatty acid oxidation (FAO), and induced M2 polarization in the tumor microenvironment (TME). RIPK3 upregulation or FAO blockade reversed the immunosuppressive activity of TAMs and dampened HCC tumorigenesis. Our findings provide molecular basis for the regulation of RIPK3-mediated, lipid metabolic reprogramming of TAMs, thus highlighting a potential strategy for targeting the immunometabolism of HCC. NSC 362856 in vitro Copyright ©2020, American Association for Cancer Research.The Drosophila male germline stem cell (GSC) lineage provides a great model to understand stem cell maintenance, proliferation, differentiation, and dedifferentiation. link2 Here we use Drosophila GSC lineage to systematically analyze transcriptome of discrete but continuous differentiating germline cysts. We first isolated single cysts at each recognizable stage from wild-type testes, which were subsequently applied for RNA-seq analyses. Our data delineate a high-resolution transcriptome atlas in the entire male GSC lineage The most dramatic switch occurs from early to late spermatocyte, followed by the change from the mitotic spermatogonia to early meiotic spermatocyte. By contrast, the transit-amplifying spermatogonia cysts display similar transcriptomes, suggesting common molecular features among these stages, which may underlie their similar behavior during both differentiation and dedifferentiation processes. Finally, distinct differentiating germ cell cyst samples do not exhibit obvious dosage compensation of X-chromosomal genes, even with consideration of the paucity of X-chromosomal gene expression during meiosis, which is different from somatic cells. Together, our single cyst-resolution, genome-wide transcriptional profile analyses provide an unprecedented resource to understand many questions in both germ cell biology and stem cell biology fields. © 2020. Published by The Company of Biologists Ltd.Control of cell number is crucial to define body size during animal development and to restrict tumoral transformation. link3 The cell number is determined by the balance between cell proliferation and cell death. Although many genes are known to regulate those processes, the molecular mechanisms underlying the relationship between cell number and body size remain poorly understood. This relationship can be better understood by studying planarians, flatworms that continuously change their body size according to nutrient availability. We identified a novel gene family, blitzschnell (bls), which consists of de novo and taxonomically restricted genes that control cell proliferationcell death ratio. Their silencing promotes faster regeneration and increases cell number during homeostasis. Importantly, this increase in cell number only leads to an increase in body size in a nutrient-rich environment; in starved planarians silencing results in a decrease in cell size and cell accumulation that ultimately produces overgrowths. bls expression is down-regulated after feeding and related with the Insulin/Akt/mTOR network activity, suggesting that the bls family evolved in planarians as an additional mechanism by which to restrict cell number in nutrient-fluctuating environments. © 2020. Published by The Company of Biologists Ltd.The Gsx2 homeodomain transcription factor promotes neural progenitor identity in the lateral ganglionic eminence (LGE), despite upregulating the neurogenic factor Ascl1. How this balance in maturation is maintained is unclear. Here, we show that Gsx2 and Ascl1 are co-expressed in subapical progenitors that have unique transcriptional signatures in LGE ventricular zone (VZ) cells. Moreover, while Ascl1 misexpression promotes neurogenesis in dorsal telencephalic progenitors, the co-expression of Gsx2 with Ascl1 inhibits neurogenesis. Using luciferase assays, we found that Gsx2 reduces the ability of Ascl1 to activate gene expression in a dose-dependent and DNA binding-independent manner. Moreover, Gsx2 physically interacts with the basic helix-loop-helix (bHLH) domain of Ascl1, and DNA binding assays demonstrated that this interaction interferes with Ascl1’s ability to bind DNA. Finally, we modified a proximity ligation assay for tissue sections and found that Ascl1Gsx2 interactions are enriched within LGE VZ progenitors, whereas Ascl1Tcf3 (E-protein) interactions predominate in the subventricular zone. Thus, Gsx2 contributes to the balance between progenitor maintenance and neurogenesis by physically interacting with Ascl1, interfering with its DNA binding, and limiting neurogenesis within LGE progenitors. © 2020. Published by The Company of Biologists Ltd.Studies in recent years have shed light on the particular features of cytoskeleton dynamics in immune cells, challenging the classical picture drawn from typical adherent cell lines. New mechanisms linking the dynamics of the membrane-cytoskeleton interface to the mechanical properties of immune cells have been uncovered and shown to be essential for immune surveillance functions. In this Essay, we discuss these features, and propose immune cells as a new playground for cell biologists who try to understand how cells adapt to different microenvironments to fulfil their functions efficiently. © 2020. Published by The Company of Biologists Ltd.BACKGROUND AND OBJECTIVES National guidelines advocate for the administration of antibiotics within 1 hour to children with septic shock, although there is variance in the pediatric evidence-based literature supporting this benchmark. Our objective for this study was to describe the association of target time to antibiotic administration (TTAA) with outcomes of children treated for suspected septic shock in a pediatric emergency department. Septic shock is suspected when signs of perfusion and/or hypotension are present. The primary outcome was mortality. Secondary outcomes included PICU admission, hospital and PICU length of stay, and organ dysfunction resolution by hospital day 2. METHODS We conducted a retrospective study of children less then 18 years of age admitted from the pediatric emergency department and treated for suspected septic shock between February 1, 2007, and December 31, 2015. Associations between TTAA and outcomes were evaluated by using multivariable linear and logistic regression models obtained from stepwise selection. RESULTS Of 1377 patients, 47% were boys with a median age of 4.0 (interquartile range 1.4-11.6) years, 1.5% (20) died, 90% were compliant with TTAA goals, 40% required PICU admission, 38% had ≥2 unique complex chronic conditions, 71% received antibiotics in ≤2 hours, and 30% had a culture-positive bacterial etiology. There were no significant associations between TTAA and outcomes. CONCLUSIONS We found no association with TTAA and any clinical outcomes, adding to the growing body of literature questioning the timing benchmark of antibiotic administration. Although the importance of antibiotics is not in question, elucidating the target TTAA may improve resource use and decrease inappropriate or unnecessary antibiotic exposure. Copyright © 2020 by the American Academy of Pediatrics.BACKGROUND Cancer projections to the current year help in policy development, planning of programs and allocation of resources. We sought to provide an overview of the expected incidence and mortality of cancer in Canada in 2020 in follow-up to the Canadian Cancer Statistics 2019 report. METHODS We obtained incidence data from the National Cancer Incidence Reporting System (1984-1991) and Canadian Cancer Registry (1992-2015). Mortality data (1984-2015) were obtained from the Canadian Vital Statistics – Death Database. All databases are maintained by Statistics Canada. Cancer incidence and mortality counts and age-standardized rates were projected to 2020 for 23 cancer types by sex and geographic region (provinces and territories) for all ages combined. RESULTS An estimated 225 800 new cancer cases and 83 300 cancer deaths are expected in Canada in 2020. The most commonly diagnosed cancers are expected to be lung overall (29 800), breast in females (27 400) and prostate in males (23 300). Lung cancer is also expected to be the leading cause of cancer death, accounting for 25.5% of all cancer deaths, followed by colorectal (11.6%), pancreatic (6.4%) and breast (6.1%) cancers. Incidence and mortality rates will be generally higher in the eastern provinces than in the western provinces. INTERPRETATION The number of cancer cases and deaths remains high in Canada and, owing to the growing and aging population, is expected to continue to increase. Although progress has been made in reducing deaths for most major cancers (breast, prostate and lung), there has been limited progress for pancreatic cancer, which is expected to be the third leading cause of cancer death in Canada in 2020. Additional efforts to improve uptake of existing programs, as well as to advance research, prevention, screening and treatment, are needed to address the cancer burden in Canada. © 2020 Joule Inc. or its licensors.The voltage-gated potassium channel Kv1.5 plays important roles in atrial repolarization and regulation of vascular tone. In the present study, we investigated the effects of mechanical stretch on Kv1.5 channels. We induced mechanical stretch by centrifuging or culturing Kv1.5-expressing HEK 293 cells and neonatal rat ventricular myocytes in low osmolarity (LO) medium, and then recorded Kv1.5 current (IKv1.5) in a normal, isotonic solution. We observed that mechanical stretch increased IKv1.5, and this increase required the intact long, proline-rich extracellular S1-S2 linker of the Kv1.5 channel. The LO-induced IKv1.5 increase also required an intact intracellular N-terminus, which contains the binding motif for endogenous Src tyrosine kinase that constitutively inhibits IKv1.5 Disrupting the Src-binding motif of Kv1.5 through N-terminal truncation or mutagenesis abolished the mechanical stretch-mediated increase in IKv1.5 Our results further showed that the extracellular S1-S2 linker of Kv1.5 communicates with the intracellular N-terminus.