Although programmed death-ligand 1-programmed death 1 (PD-L1-PD-1) inhibitors are broadly efficacious, improved outcomes have been observed in patients with high PD-L1 expression or high tumor mutational burden (TMB). PD-L1 testing is required for checkpoint inhibitor monotherapy in front-line non-small-cell lung cancer (NSCLC). However, obtaining adequate tumor tissue for molecular testing in patients with advanced disease can be challenging. Thus, an unmet medical need exists for diagnostic approaches that do not require tissue to identify patients who may benefit from immunotherapy. Here, we describe a novel, technically robust, blood-based assay to measure TMB in plasma (bTMB) that is distinct from tissue-based approaches. Using a retrospective analysis of two large randomized trials as test and validation studies, we show that bTMB reproducibly identifies patients who derive clinically significant improvements in progression-free survival from atezolizumab (an anti-PD-L1) in second-line and higher NSCLC. Collectively, our data show that high bTMB is a clinically actionable biomarker for atezolizumab in NSCLC.

Interleukin 1 receptor antagonist (IL-ira) is a cytokine whose only known action is competitive inhibition of the binding of interleukin 1 (IL-1) to its receptor. To investigate the physiological roles of endogenously produced IL-Ira, we generated mice that either lack IL-lra or overproduce it under control of the endogenous promoter. Mice lacking IL-lra have decreased body mass compared with wild-type controls. They are more susceptible than controls to lethal endotoxemia but are less susceptible to infection with Listeria monocytogenes. Conversely, IL-lra overproducers are protected from the lethal effects of endotoxin but are more susceptible to listeriosis. Serum levels of IL-1 following an endotoxin challenge are decreased in IL-lra nulls and increased in IL-lra overproducers in comparison to controls. These data demonstrate critical roles for endogenously produced IL-lra in growth, responses to infection and inflammation, and regulation of cytokine expression.Interleukin 1 (IL-1) is a proinflammatory cytokine that participates in the response to infectious and inflammatory challenges by recruiting and activating neutrophils and macrophages, by producing fever and vascular dilation, and by inducing mediators such as IL-6, acute phase reactants, and prostaglandin E2 (reviewed in ref.

The integrity of polarized epithelia is critical for development and human health. Many questions remain concerning the full complement and the function of the proteins that regulate cell polarity. Here we report that the Drosophila FERM proteins Yurt (Yrt) and Coracle (Cora) and the membrane proteins Neurexin IV (Nrx-IV) and Na(+),K(+)-ATPase are a new group of functionally cooperating epithelial polarity proteins. This 'Yrt/Cora group' promotes basolateral membrane stability and shows negative regulatory interactions with the apical determinant Crumbs (Crb). Genetic analyses indicate that Nrx-IV and Na(+),K(+)-ATPase act together with Cora in one pathway, whereas Yrt acts in a second redundant pathway. Moreover, we show that the Yrt/Cora group is essential for epithelial polarity during organogenesis but not when epithelial polarity is first established or during terminal differentiation. This property of Yrt/Cora group proteins explains the recovery of polarity in embryos lacking the function of the Lethal giant larvae (Lgl) group of basolateral polarity proteins. We also find that the mammalian Yrt orthologue EPB41L5 (also known as YMO1 and Limulus) is required for lateral membrane formation, indicating a conserved function of Yrt proteins in epithelial polarity.

Although the correct architecture of epithelial tubes is crucial for the function of organs such as the lung, kidney and vascular system, little is known about the molecular mechanisms that control tube size. We show that mutations in the ATPα α and nrv2 β subunits of the Na+/K+ ATPase cause Drosophila tracheal tubes to have increased lengths and expanded diameters. ATPαand nrv2 mutations also disrupt stable formation of septate junctions, structures with some functional and molecular similarities to vertebrate tight junctions. The Nrv2 β subunit isoforms have unique tube size and junctional functions because Nrv2, but not other DrosophilaNa+/K+ ATPase β subunits, can rescue nrv2mutant phenotypes. Mutations in known septate junctions genes cause the same tracheal tube-size defects as ATPα and nrv2 mutations,indicating that septate junctions have a previously unidentified role in epithelial tube-size control. Double mutant analyses suggest that tube-size control by septate junctions is mediated by at least two discernable pathways,although the paracellular diffusion barrier function does not appear to involved because tube-size control and diffusion barrier function are genetically separable. Together, our results demonstrate that specific isoforms of the Na+/K+ ATPase play a crucial role in septate junction function and that septate junctions have multiple distinct functions that regulate paracellular transport and epithelial tube size.

Summary Uncoupling protein 1 (UCP1) mediates non-shivering thermogenesis and, upon cold exposure, is induced in BAT and subcutaneous white adipose tissue (iWAT). Here, by high-throughput screening using the UCP1 promoter, we identify Zfp516 as a novel transcriptional activator of UCP1 as well as PGC1α thereby promoting a BAT program. Zfp516 itself is induced by cold and sympathetic stimulation through the cAMP-CREB/ATF2 pathway. Zfp516 directly binds to the proximal region of the UCP1 promoter, not to the enhancer region where other transcription factors bind, and interacts with PRDM16 to activate the UCP1 promoter. Although ablation of Zfp516 causes embryonic lethality, knockout embryos still show drastically reduced BAT mass. Overexpression of Zfp516 in adipose tissue promotes browning of iWAT even at room temperature, increasing body temperature, energy expenditure, and preventing diet-induced obesity. Zfp516 may represent a future target for obesity therapeutics.