Publications by authors named "Michael Pierce"

Ricin, a category-B agent for bioterrorism, and Shiga toxins (Stxs), which cause food poisoning bind to the ribosomal P-stalk to depurinate the sarcin/ricin loop. No effective therapy exists for ricin or Stx intoxication. Ribosome binding sites of the toxins have not been targeted by small molecules.

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Background: CEACAM5 and CEACAM6 are glycosylphosphatidylinositol (GPI)- linked members of the carcinoembryonic antigen-related cell adhesion molecule (CEACAM) family, which are frequently upregulated in epithelial cancers where they contribute to invasion, metastasis, immune evasion, and resistance to anoikis. CT109 is a novel antibody with dual specificity to both CEACAM5 and 6.

Objectives: In this study, we aimed to perform the preclinical characterization of CT109 and antibody- drug conjugate (ADCs) derivatives of CT109, focusing on CT109-SN-38.

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The rise of multidrug-resistant (MDR) pathogens, especially MDR Gram-negatives, poses a significant challenge to clinicians and public health. These resilient bacteria have rendered many traditional antibiotics ineffective, underscoring the urgency for innovative therapeutic solutions. Eravacycline, a broad-spectrum fluorocycline tetracycline antibiotic approved by the FDA in 2018, emerges as a promising candidate, exhibiting potential against a diverse array of MDR bacteria, including Gram-negative, Gram-positive, anaerobic strains, and Mycobacterium.

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Forty-six patients were treated with eravacycline (ERV) for Acinetobacter baumannii infections, where 69.5% of isolates were carbapenem resistant (CRAB). Infections were primarily pulmonary (58.

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infections may be overlooked by clinicians due to the uncommon encounter of this pathogen in humans and common isolation of co-pathogens. However, the isolation of in immunocompromised individuals may represent a true infection. We report our experience with the fatal case of a stem cell transplant recipient, co-infected with SARS-CoV-2 and , who was considered fully vaccinated (two doses) at the time of her case in spring 2021.

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Article Synopsis
  • Human intelectin-1 (hIntL-1) is a protein that can bind to specific sugars on the surface of pathogens like Streptococcus pneumoniae, which can lead to increased immune responses.
  • This study focuses on hIntL-1's interactions with S. pneumoniae serotype 43, showing it can agglutinate the bacteria but does not kill them through the expected immune mechanisms.
  • However, hIntL-1 does enhance the ability of neutrophils to kill these bacteria and helps them attach to lung cells, indicating its role in immune surveillance and targeting harmful pathogens.
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Ricin toxin A subunit (RTA) is the catalytic subunit of ricin, which depurinates an adenine from the sarcin/ricin loop in eukaryotic ribosomes. There are no approved inhibitors against ricin. We used a new strategy to disrupt RTA-ribosome interactions by fragment screening using surface plasmon resonance.

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We aimed to determine the mechanism of epithelial-mesenchymal transition (EMT)-induced stemness in cancer cells. Cancer relapse and metastasis are caused by rare stem-like cells within tumors. Studies of stem cell reprogramming have linked repression and acquisition of stemness with the EMT factor, .

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Ricin undergoes retrograde transport to the endoplasmic reticulum (ER), and ricin toxin A chain (RTA) enters the cytosol from the ER. Previous reports indicated that RTA inhibits activation of the unfolded protein response (UPR) in yeast and in mammalian cells. Both precursor (preRTA) and mature form of RTA (mRTA) inhibited splicing of ( for uninduced) mRNA, suggesting that UPR inhibition occurred on the cytosolic face of the ER.

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Electrochemical double layers (EDL) form at electrified interfaces. Whereas the Gouy-Chapman model describes moderately charged EDL, the formation of Stern layers was predicted for highly charged EDL. Our results provide structural evidence for a Stern layer of cations at potentials close to hydrogen evolution in alkali fluoride and chloride electrolytes.

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Rapid and continued growth in the generation of glycomic data has revealed the need for enhanced development of basic infrastructure for presenting and interpreting these datasets in a manner that engages the broader biomedical research community. Early in their growth, the genomic and proteomic fields implemented mechanisms for assigning unique gene and protein identifiers that were essential for organizing data presentation and for enhancing bioinformatic approaches to extracting knowledge. Similar unique identifiers are currently absent from glycomic data.

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To study the regulation of colorectal adenocarcinoma progression by -GlcNAc, we have focused on the -GlcNAc-mediated epigenetic regulation of human colon cancer stem cells (CCSC). Xenograft tumors from colon tumor cells with -linked -acetylglucosamine transferase (OGT) knockdown grew significantly slower than those formed from control cells, indicating a reduced proliferation of tumor cells due to inhibition of OGT expression. Significant reduction of the CCSC population was observed in the tumor cells after OGT knockdown, whereas tumor cells treated with the -GlcNAcase inhibitor showed an increased CCSC population, indicating that -GlcNAc levels regulated the CCSC compartment.

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Dysregulation of tumor suppressor protein E-cadherin is an early molecular event in cancer. O-mannosylation profile of E-cadherin is a newly-described post-translational modification crucial for its adhesive functions in homeostasis. However, the role of O-mannosyl glycans in E-cadherin-mediated cell adhesion in cancer and their interplay with N-glycans remains largely unknown.

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This paper describes solid form control and particle size control of RG3487, a nicotinic receptor partial agonist. Four crystal forms were identified by polymorph screen under ∼100 varying conditions. Form A and Form B are anhydrates, while Forms C and D are solvates.

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Polysialic acid (PSA) is a carbohydrate polymer of repeating α-2,8 sialic acid residues that decorates multiple targets, including neural cell adhesion molecule (NCAM). PST and STX encode the two enzymes responsible for PSA modification of target proteins in mammalian cells, but despite widespread polysialylation in embryonic development, the majority of studies have focused strictly on the role of PSA in neurogenesis. Using human pluripotent stem cells (hPSCs), we have revisited the developmental role of PST and STX and show that early progenitors of the three embryonic germ layers are polysialylated on their cell surface.

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Glycans are known as the third major class of biopolymers, next to DNA and proteins. They cover the surfaces of many cells, serving as the 'face' of cells, whereby other biomolecules and viruses interact. The structure of glycans, however, differs greatly from DNA and proteins in that they are branched, as opposed to linear sequences of amino acids or nucleotides.

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The applied potential dependent rate of atomic step motion of the Ag(001) surface in weak NaF electrolyte has been measured using a new extension of the technique of X-ray Photon Correlation Spectroscopy (XPCS). For applied potentials between hydrogen evolution and oxidation, the surface configuration completely changes on timescales of 10(2)-10(4) seconds depending upon the applied potential. These dynamics, directly measured over large areas of the sample surface simultaneously, are related to the surface energy relative to over or under potential.

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Deletion of GnT-V (MGAT5), which synthesizes N-glycans with β(1,6)-branched glycans, reduced the compartment of cancer stem cells (CSC) in the her-2 mouse model of breast cancer, leading to delay of tumor onset. Because GnT-V levels are also commonly up-regulated in colon cancer, we investigated their regulation of colon CSC and adenoma development. Anchorage-independent cell growth and tumor formation induced by injection of colon tumor cells into NOD/SCID mice were positively associated with GnT-V levels, indicating regulation of proliferation and tumorigenicity.

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We developed a method for production of arrays of platinum nanocrystals of controlled size and shape using templates from ordered silica bead monolayers. Silica beads with nominal sizes of 150 and 450 nm were self-assembled into monolayers over strontium titanate single crystal substrates. The monolayers were used as shadow masks for platinum metal deposition on the substrate using the three-step evaporation technique.

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The glycosylphosphatidylinositol (GPI) anchor is a glycan and lipid posttranslational modification added to proteins in the endoplasmic reticulum. Certain enzymes within the GPI biosynthetic pathway, particularly the subunits of the GPI transamidase, are elevated in various human cancers. Specific GPI anchored proteins, such as carcinoembryonic antigen and mesothelin, have been described as potential biomarkers for certain cancers; however, the overall levels of GPI anchored proteins present in plasma from cases of human cancers have not been evaluated.

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Glycomics is a broad and emerging scientific discipline focused on defining the structures and functional roles of glycans in biological systems. The staggering complexity of the glycome, minimally defined as the repertoire of glycans expressed in a cell or organism, has resulted in many challenges that must be overcome; these are being addressed by new advances in mass spectrometry as well as by the expansion of genetic and cell biology studies. Conversely, identifying the specific glycan recognition determinants of glycan-binding proteins by employing the new technology of glycan microarrays is providing insights into how glycans function in recognition and signaling within an organism and with microbes and pathogens.

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