IL-2/anti-IL-2 antibody complexes augment immune responses to therapeutic cancer vaccines.

One driver of the high failure rates of clinical trials for therapeutic cancer vaccines is likely the inability to sufficiently engage conventional dendritic cells (cDCs), the antigen-presenting cell (APC) subset that is specialized in priming antitumor T cells. Here, we demonstrate that, relative to vaccination with an injectable mesoporous silica rod (MPS) vaccine alone (Vax), combining MPS vaccines with CD122-biased IL-2/anti-IL-2 antibody complexes (IL-2cx) drives ~3-fold expansion of cDCs at the vaccination sites, vaccine-draining lymph nodes, and spleens of treated mice. Furthermore, relative to Vax alone, Vax+IL-2cx led to a ~3-fold increase in the numbers of CD8 T cells and ~15-fold increase in the numbers of NK cells at the vaccination site.

Raman amplifier based on stimulated Raman scattering in a methane-filled hollow core fiber.

This article reports on a single pass amplifier based on stimulated Raman scattering in a methane-filled negative curvature hollow core fiber (HCF) to transition 1.06 μm power to 1.54 μm.

FAST-EM array tomography: a workflow for multibeam volume electron microscopy.

Elucidating the 3D nanoscale structure of tissues and cells is essential for understanding the complexity of biological processes. Electron microscopy (EM) offers the resolution needed for reliable interpretation, but the limited throughput of electron microscopes has hindered its ability to effectively image large volumes. We report a workflow for volume EM with FAST-EM, a novel multibeam scanning transmission electron microscope that speeds up acquisition by scanning the sample in parallel with 64 electron beams.

A large-scale cancer-specific protein-DNA interaction network.

Cancer development and progression are generally associated with gene dysregulation, often resulting from changes in the transcription factor (TF) sequence or expression. Identifying key TFs involved in cancer gene regulation provides a framework for potential new therapeutics. This study presents a large-scale cancer gene TF-DNA interaction network, as well as an extensive promoter clone resource for future studies.

Durable lymph-node expansion is associated with the efficacy of therapeutic vaccination.

Following immunization, lymph nodes dynamically expand and contract. The mechanical and cellular changes enabling the early-stage expansion of lymph nodes have been characterized, yet the durability of such responses and their implications for adaptive immunity and vaccine efficacy are unknown. Here, by leveraging high-frequency ultrasound imaging of the lymph nodes of mice, we report more potent and persistent lymph-node expansion for animals immunized with a mesoporous silica vaccine incorporating a model antigen than for animals given bolus immunization or standard vaccine formulations such as alum, and that durable and robust lymph-node expansion was associated with vaccine efficacy and adaptive immunity for 100 days post-vaccination in a mouse model of melanoma.

Widespread variation in molecular interactions and regulatory properties among transcription factor isoforms.

Most human Transcription factors (TFs) genes encode multiple protein isoforms differing in DNA binding domains, effector domains, or other protein regions. The global extent to which this results in functional differences between isoforms remains unknown. Here, we systematically compared 693 isoforms of 246 TF genes, assessing DNA binding, protein binding, transcriptional activation, subcellular localization, and condensate formation.

A large-scale cancer-specific protein-DNA interaction network.

Cancer development and progression are generally associated with dysregulation of gene expression, often resulting from changes in transcription factor (TF) sequence or expression. Identifying key TFs involved in cancer gene regulation provides a framework for potential new therapeutics. This study presents a large-scale cancer gene TF-DNA interaction network as well as an extensive promoter clone resource for future studies.

Optical STEM detection for scanning electron microscopy.

Recent advances in electron microscopy techniques have led to a significant scale up in volumetric imaging of biological tissue. The throughput of electron microscopes, however, remains a limiting factor for the volume that can be imaged in high resolution within reasonable time. Faster detection methods will improve throughput.

Paired yeast one-hybrid assays to detect DNA-binding cooperativity and antagonism across transcription factors.

Cooperativity and antagonism between transcription factors (TFs) can drastically modify their binding to regulatory DNA elements. While mapping these relationships between TFs is important for understanding their context-specific functions, existing approaches either rely on DNA binding motif predictions, interrogate one TF at a time, or study individual TFs in parallel. Here, we introduce paired yeast one-hybrid (pY1H) assays to detect cooperativity and antagonism across hundreds of TF-pairs at DNA regions of interest.

The effects of NF-κB suppression on the early healing response following intrasynovial tendon repair in a canine model.

The highly variable clinical outcomes noted after intrasynovial tendon repair have been associated with an early inflammatory response leading to the development of fibrovascular adhesions. Prior efforts to broadly suppress this inflammatory response have been largely unsuccessful. Recent studies have shown that selective inhibition of IkappaB kinase beta (IKK-β), an upstream activator of nuclear factor kappa-light chain enhancer of activated B cells (NF-κB) signaling, mitigates the early inflammatory response and leads to improved tendon healing outcomes.

Extracellular Vesicles From Primed Adipose-Derived Stem Cells Enhance Achilles Tendon Repair by Reducing Inflammation and Promoting Intrinsic Healing.

Achilles tendon rupture is a common sports-related injury. Even with advanced clinical treatments, many patients suffer from long-term pain and functional deficits. These unsatisfactory outcomes result primarily from an imbalanced injury response with excessive inflammation and inadequate tendon regeneration.

Extracellular Vesicles from Inflammation-Primed Adipose-Derived Stem Cells Enhance Achilles Tendon Repair by Reducing Inflammation and Promoting Intrinsic Healing.

Unlabelled: Achilles tendon rupture is a common sports-related tendon injury. Even with advanced clinical treatments, many patients suffer from long-term pain and reduced function. These unsatisfactory outcomes result primarily from an imbalanced injury response with excessive inflammation and inadequate regeneration.

How innovations in methodology offer new prospects for volume electron microscopy.

Detailed knowledge of biological structure has been key in understanding biology at several levels of organisation, from organs to cells and proteins. Volume electron microscopy (volume EM) provides high resolution 3D structural information about tissues on the nanometre scale. However, the throughput rate of conventional electron microscopes has limited the volume size and number of samples that can be imaged.

Metabolic regulation of intrasynovial flexor tendon repair: The effects of dichloroacetate administration on early tendon healing in a canine model.

Enriched in glycolytic enzymes, paucicellular and hypovascular intrasynovial flexor tendons fail to mount an effective healing response after injury and repair. In contrast, well-vascularized extrasynovial flexor tendons possess high levels of oxidative phosphorylation (OXPHOS) enzymes and have a markedly improved healing capacity. This study was designed to compare the metabolic profiles of the two types of tendons and to evaluate the impact of metabolic reprogramming on early intrasynovial tendon healing in a clinically relevant canine model.

Integrated Array Tomography for 3D Correlative Light and Electron Microscopy.

Volume electron microscopy (EM) of biological systems has grown exponentially in recent years due to innovative large-scale imaging approaches. As a standalone imaging method, however, large-scale EM typically has two major limitations: slow rates of acquisition and the difficulty to provide targeted biological information. We developed a 3D image acquisition and reconstruction pipeline that overcomes both of these limitations by using a widefield fluorescence microscope integrated inside of a scanning electron microscope.

In Situ Tumor Vaccination with Nanoparticle Co-Delivering CpG and STAT3 siRNA to Effectively Induce Whole-Body Antitumor Immune Response.

The success of immunotherapy with immune checkpoint inhibitors (ICIs) in a subset of individuals has been very exciting. However, in many cancers, responses to current ICIs are modest and are seen only in a small subsets of patients. Herein, a widely applicable approach that increases the benefit of ICIs is reported.

Gremlin 1 fibroblastic niche maintains dendritic cell homeostasis in lymphoid tissues.

Fibroblastic reticular cells (FRCs) are specialized stromal cells that define tissue architecture and regulate lymphocyte compartmentalization, homeostasis, and innate and adaptive immunity in secondary lymphoid organs (SLOs). In the present study, we used single-cell RNA sequencing (scRNA-seq) of human and mouse lymph nodes (LNs) to identify a subset of T cell-zone FRCs defined by the expression of Gremlin1 (Grem1) in both species. Grem1-CreER knock-in mice enabled localization, multi-omics characterization and genetic depletion of Grem1 FRCs.

Optimization of negative stage bias potential for faster imaging in large-scale electron microscopy.

Large-scale electron microscopy (EM) allows analysis of both tissues and macromolecules in a semi-automated manner, but acquisition rate forms a bottleneck. We reasoned that a negative bias potential may be used to enhance signal collection, allowing shorter dwell times and thus increasing imaging speed. Negative bias potential has previously been used to tune penetration depth in block-face imaging.

Retarding Field Integrated Fluorescence and Electron Microscope.

The authors present the application of a retarding field between the electron objective lens and sample in an integrated fluorescence and electron microscope. The retarding field enhances signal collection and signal strength in the electron microscope. This is beneficial for samples prepared for integrated fluorescence and electron microscopy as the amount of staining material added to enhance electron microscopy signal is typically lower compared to conventional samples in order to preserve fluorescence.

Quantifying Leukocyte Egress via Lymphatic Vessels from Murine Skin and Tumors.

Leukocyte egress from peripheral tissues to draining lymph nodes is not only critical for immune surveillance and initiation but also contributes to the resolution of peripheral tissue responses. While a variety of methods are used to quantify leukocyte egress from non-lymphoid, peripheral tissues, the cellular and molecular mechanisms that govern context-dependent egress remain poorly understood. Here, we describe the use of in situ photoconversion for quantitative analysis of leukocyte egress from murine skin and tumors.

Non-hematopoietic Control of Peripheral Tissue T Cell Responses: Implications for Solid Tumors.

In response to pathological challenge, the host generates rapid, protective adaptive immune responses while simultaneously maintaining tolerance to self and limiting immune pathology. Peripheral tissues (e.g.

IFNγ-activated dermal lymphatic vessels inhibit cytotoxic T cells in melanoma and inflamed skin.

Mechanisms of immune suppression in peripheral tissues counteract protective immunity to prevent immunopathology and are coopted by tumors for immune evasion. While lymphatic vessels facilitate T cell priming, they also exert immune suppressive effects in lymph nodes at steady-state. Therefore, we hypothesized that peripheral lymphatic vessels acquire suppressive mechanisms to limit local effector CD8 T cell accumulation in murine skin.

Numerical investigation of pulsed gas amplifiers operating in hollow-core optical fibers.

Optically pumped molecular gas amplifiers having a gain medium contained in a hollow-core optical fiber are investigated with numerical modeling to understand the primary physical processes that affect amplifier output and efficiency. A comparison of computational results with experimental measurements of incident pump, absorbed pump, and emitted mid-IR from a pulsed, acetylene-filled, hollow-core fiber amplifier [ Opt. Exp.