Publications by authors named "Burkhardt P"

The transition from simple to complex multicellularity involves division of labor and specialization of cell types. In animals, complex sensory-motor systems are primarily built around specialized cells of muscles and neurons, though the evolutionary origins of these and their integration remain unclear. Here, to investigate sensory-behavior coupling in the closest relatives of animals, we established a line of the choanoflagellate, which stably expresses the calcium indicator RGECO1.

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Reverse development, or the ability to rejuvenate by morphological reorganization into the preceding life cycle stage is thought to be restricted to a few species within Cnidaria. To date, is the only known species capable of undergoing reverse development after the onset of sexual reproduction. Here, we demonstrate that the ctenophore is capable of reversal from mature lobate to early cydippid when fed following a period of stress.

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Biomolecular assemblies are fundamental to life and viral disease. The spatiotemporal coordination of viral replication and assembly is largely unknown. Here, we developed a dual-color click chemistry procedure for imaging adenovirus DNA (vDNA) replication in the cell nucleus.

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Unlabelled: As the closest living relatives of animals, choanoflagellates offer insights into the ancestry of animal cell physiology. Here, we report the isolation and characterization of a colonial choanoflagellate from Mono Lake, California. The choanoflagellate forms large spherical colonies that are an order of magnitude larger than those formed by the closely related choanoflagellate .

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Chimeric antigen receptor T cells (CART) targeting lymphocyte antigens can induce T cell fratricide and require additional engineering to mitigate self-damage. We demonstrate that the expression of a chimeric antigen receptor (CAR) targeting CD5, a prominent pan-T cell antigen, induces rapid internalization and complete loss of the CD5 protein on T cells, protecting them from self-targeting. Notably, exposure of healthy and malignant T cells to CD5.

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Article Synopsis
  • The study investigates the evolution and function of SPIRE actin nucleators, crucial for organelle transport in mammalian cells.
  • SPIRE proteins are found in holozoans, including choanoflagellates, and they interact with various proteins to facilitate actin filament formation and organelle movement.
  • The findings suggest that SPIRE originated in unicellular ancestors of animals, potentially playing a key role in the development of more complex multicellular organisms.
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Ctenophores are marine organisms attracting significant attention from evolutionary biology, molecular biology, and ecological research. Here, we describe an easy and affordable setup to maintain a stable culture of the ctenophore Mnemiopsis leidyi. The challenging delicacy of the lobate ctenophores can be met by monitoring the water quality, providing the right nutrition, and adapting the handling and tank set-up to their fragile gelatinous body plan.

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Background: Using Otoplan software, it is possible to measure the cochlea before cochlear implant surgery. Until now, computed tomography (CT) of the cochlea has been necessary for this purpose. The aim of this study was to find out whether measuring the cochlea with magnetic resonance imaging (MRI) using Otoplan is possible with the same accuracy.

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Article Synopsis
  • The "ribbon" structure of connected Golgi stacks is typically thought to exist only in vertebrates, but this study suggests it might have originated earlier in animal evolution.
  • Researchers found ribbon-like structures in various metazoans, indicating that this architectural feature predates vertebrates and may be linked to processes like embryogenesis.
  • The study proposes that the evolution of specific proteins (GRASP) may have facilitated the formation of these Golgi ribbons, which could have important biological roles that are still not fully understood.
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Despite newer targeted therapies, patients with primary refractory or relapsed (r/r) T-cell lymphoma have a poor prognosis. The development of chimeric antigen receptor (CAR) T-cell platforms to treat T-cell malignancies often requires additional gene modifications to overcome fratricide because of shared T-cell antigens on normal and malignant T cells. We developed a CD5-directed CAR that produces minimal fratricide by downmodulating CD5 protein levels in transduced T cells while retaining strong cytotoxicity against CD5+ malignant cells.

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Certain environmental chemicals affect the body's energy balance and are known as metabolism disrupting chemicals (MDCs). MDCs have been implicated in the development of metabolic diseases, such as obesity and type 2 diabetes. In contrast to their well-known impact on developing adipocytes, MDC effects leading to altered energy balance and development of insulin resistance in mature white adipocytes, constituents of adult adipose tissue, are largely unclear.

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The ichthyosporean Sphaeroforma arctica, a protist closely related to animals, displays coenocytic development followed by cellularization and cell release. A new study reveals that the nuclear-to-cytoplasmic ratio drives cellularization in these fascinating organisms.

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A fundamental breakthrough in neurobiology has been the formulation of the neuron doctrine by Santiago Ramón y Cajal, which stated that the nervous system is composed of discrete cells. Electron microscopy later confirmed the doctrine and allowed the identification of synaptic connections. In this work, we used volume electron microscopy and three-dimensional reconstructions to characterize the nerve net of a ctenophore, a marine invertebrate that belongs to one of the earliest-branching animal lineages.

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A cochlear implant (CI) can partially restore hearing in individuals with profound sensorineural hearing loss. However, electrical hearing with a CI is limited and highly variable. The current study aimed to better understand the different factors contributing to this variability by examining how age affects cognitive functions and cortical speech processing in CI users.

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Chronic exposure to airborne carbon black ultrafine (nCB) particles generated from incomplete combustion of organic matter drives IL-17A-dependent emphysema. However, whether and how they alter the immune responses to lung cancer remains unknown. Here, we show that exposure to nCB particles increased PD-L1 PD-L2 CD206 antigen-presenting cells (APCs), exhausted T cells, and T cells.

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Ctenophores (commonly known as comb jellies) are among the earliest branching extant lineages of the animal kingdom. Here, I present a brief overview of the ctenophore nervous system, discussing its cellular architecture and molecular composition, as well as insights it offers into the early evolution of neurons and chemical neurotransmission.

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Neurons, especially when coupled with muscles, allow animals to interact with and navigate through their environment in ways unique to life on earth. Found in all major animal lineages except sponges and placozoans, nervous systems range widely in organization and complexity, with neurons possibly representing the most diverse cell-type. This diversity has led to much debate over the evolutionary origin of neurons as well as synapses, which allow for the directed transmission of information.

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Acute graft-versus-host disease (aGVHD) limits the therapeutic benefit of allogeneic hematopoietic stem cell transplantation (allo-HSCT) and requires immunosuppressive prophylaxis that compromises antitumor and antipathogen immunity. OX40 is a costimulatory receptor upregulated on circulating T cells in aGVHD and plays a central role in driving the expansion of alloreactive T cells. Here, we show that OX40 is also upregulated on T cells infiltrating GVHD target organs in a rhesus macaque model, supporting the hypothesis that targeted ablation of OX40+ T cells will mitigate GVHD pathogenesis.

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In vitro models of adipogenesis are phenotypic assays that most closely mimic the increase of adipose tissue in obesity. Current models, however, often lack throughput and sensitivity and even report conflicting data regarding adipogenic potencies of many chemicals. Here, we describe a ten-day long adipogenesis model using high content analysis readouts for adipocyte number, size, and lipid content on primary human mesenchymal stem cells (MSC) sensitive enough to compare bisphenol A derivatives quantitatively in a robust and high throughput manner.

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Chromatin regulation is a key process in development but its contribution to the evolution of animals is largely unexplored. Chromatin is regulated by a diverse set of proteins, which themselves are tightly regulated in a cell/tissue-specific manner. Using the cnidarian Nematostella vectensis as a basal metazoan model, we explore the function of one such chromatin regulator, Lysine specific demethylase 1 (Lsd1).

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Nervous systems evolved around 560 million years ago to coordinate and empower animal bodies. Ctenophores - one of the earliest-branching lineages - are thought to share a few neuronal genes with bilaterians and may have evolved neurons convergently. Here we review our current understanding of the evolution of neuronal molecules in nonbilaterians.

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The evolutionary origin of metazoan cell types such as neurons and muscles is not known. Using whole-body single-cell RNA sequencing in a sponge, an animal without nervous system and musculature, we identified 18 distinct cell types. These include nitric oxide–sensitive contractile pinacocytes, amoeboid phagocytes, and secretory neuroid cells that reside in close contact with digestive choanocytes that express scaffolding and receptor proteins.

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Ctenophores are gelatinous marine animals famous for locomotion by ciliary combs. Due to the uncertainties of the phylogenetic placement of ctenophores and the absence of some key bilaterian neuronal genes, it has been hypothesized that their neurons evolved independently. Additionally, recent whole-body, single-cell RNA sequencing (scRNA-seq) analysis failed to identify ctenophore neurons using any of the known neuronal molecular markers.

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Neurosecretory vesicles are highly specialized trafficking organelles that store neurotransmitters that are released at presynaptic nerve endings and are, therefore, important for animal cell-cell signalling. Despite considerable anatomical and functional diversity of neurons in animals, the protein composition of neurosecretory vesicles in bilaterians appears to be similar. This similarity points towards a common evolutionary origin.

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