Antibodies targeting immune checkpoints are emerging as potent and viable cancer therapies, but not all patients respond to these as single agents. Concurrently targeting additional immunosuppressive pathways is a promising approach to enhance immune checkpoint blockade, and bifunctional molecules designed to target two pathways simultaneously may provide a strategic advantage over the combination of two single agents. M7824 (MSB0011359C) is a bifunctional fusion protein composed of a monoclonal antibody against programmed death ligand 1 (PD-L1) fused to the extracellular domain of human transforming growth factor-β (TGF-β) receptor II, which functions as a "trap" for all three TGF-β isoforms. We demonstrate that M7824 efficiently, specifically, and simultaneously binds PD-L1 and TGF-β. In syngeneic mouse models, M7824 suppressed tumor growth and metastasis more effectively than treatment with either an anti-PD-L1 antibody or TGF-β trap alone; furthermore, M7824 extended survival and conferred long-term protective antitumor immunity. Mechanistically, the dual anti-immunosuppressive function of M7824 resulted in activation of both the innate and adaptive immune systems, which contributed to M7824's antitumor activity. Finally, M7824 was an effective combination partner for radiotherapy or chemotherapy in mouse models. Collectively, our preclinical data demonstrate that simultaneous blockade of the PD-L1 and TGF-β pathways by M7824 elicits potent and superior antitumor activity relative to monotherapies.

2016-12-23T18:47:23

We report a study of ν(μ) charged-current quasielastic events in the segmented scintillator inner tracker of the MINERvA experiment running in the NuMI neutrino beam at Fermilab. The events were selected by requiring a μ- and low calorimetric recoil energy separated from the interaction vertex. We measure the flux-averaged differential cross section, dσ/dQ², and study the low energy particle content of the final state. Deviations are found between the measured dσ/dQ² and the expectations of a model of independent nucleons in a relativistic Fermi gas. We also observe an excess of energy near the vertex consistent with multiple protons in the final state.

We use genome-wide nucleosome maps to study sequence specificity of intrinsic histone-DNA interactions. In contrast with previous approaches, we employ an analogy between a classical one-dimensional fluid of finite-size particles in an arbitrary external potential and arrays of DNA-bound histone octamers. We derive an analytical solution to infer free energies of nucleosome formation directly from nucleosome occupancies measured in high-throughput experiments. The sequence-specific part of free energies is then captured by fitting them to a sum of energies assigned to individual nucleotide motifs. We have developed hierarchical models of increasing complexity and spatial resolution, establishing that nucleosome occupancies can be explained by systematic differences in mono-and dinucleotide content between nucleosomal and linker DNA sequences, with periodic dinucleotide distributions and longer sequence motifs playing a minor role. Furthermore, similar sequence signatures are exhibited by control experiments in which nucleosome-free genomic DNA is either sonicated or digested with micrococcal nuclease, making it possible that current predictions based on high-throughput nucleosomepositioning maps are biased by experimental artifacts.chromatin structure | histone-DNA interactions | nucleosome positioning | biophysical models I n eukaryotes, 75%-90% of genomic DNA is packaged into histone-DNA complexes called nucleosomes, with adjacent nucleosomes separated by stretches of linker DNA (1). Each nucleosome consists of 147 base pairs (bp) of DNA wrapped around a histone octamer in a left-handed superhelix (2). Arrays of nucleosomes fold into filamentous chromatin fibers which constitute building blocks for higher-order structures (3). DNA wrapped in a nucleosome is occluded from interacting with other DNA-binding proteins such as transcription factors, RNA polymerase, and DNA repair complexes (2). On the other hand, histone tail domains act as substrates for posttranslational modifications, providing binding sites for chromatin-associated proteins which facilitate transitions between active and silent chromatin states (4).Several distinct factors affect nucleosome positions in living cells. First of all, intrinsic histone-DNA interactions are sequence-specific: for example, polyðdA∶dTÞ tracts are well known to disfavor nucleosome formation (5, 6). In addition, nucleosome-depleted regions can be generated through the action of ATP-dependent chromatin remodeling enzymes (7) and histone acetylases (8). Finally, non-histone DNA-binding factors can alter nucleosome positions through binding their cognate sites and either displacing nucleosomes or hindering their subsequent formation (9, 10).The nucleosome code hypothesis states that DNA sequence is the primary determinant of nucleosome positions in living cells (11). This hypothesis is often contrasted with the idea of statistical positioning which asserts that most nucleosomes are ordered into regular arrays simply by steric exclusion (12, 13). In this view the nucleosoma...