Biology subjects

Rose, J. B.

Publications and source records attributed to Rose, J. B..

5 recordsLinked to original sources

bioRxiv2026

Bacterial Membrane Vesicles in Wastewater Disseminate Antibiotic Resistance Genes

Bacterial membrane vesicles (BMVs) have emerged as important contributors to the dissemination of antibiotic resistance genes (ARGs) in the environment. Here, we developed a high-performance immunomagnetic isolation method that improves the purity and selectivity of BMV recovery from wastewater, minimizes contamination from eDNA and viruses, and enables differentiation of BMVs originating from Gram-positive versus Gram-negative bacteria with minimal cross-reactivity. Using this approach, we found that ARGs such as the kanamycin resistance gene (kanR) was highly abundant in BMVs from both raw and treated wastewater, exhibited persistence following treatment, and retained the ability to generate antibiotic-resistant bacteria via transformation. Metagenomic sequencing further revealed that tetracycline resistance genes were the most abundant ARG class across all wastewater samples, while the composition of BMV-associated ARGs differed from the bulk ARG profile. These findings highlight the critical yet underrecognized role of BMVs in the spread of antimicrobial resistance and underscore the need to address BMV-mediated pathways within a One Health framework linking environmental and human health.

microbiology↗

bioRxiv2025

Generation of a Synthetic Single Domain Antibody Library for Radiopharmaceutical Ligand Discovery

Single domain antibodies, often known as nanobodies, are versatile molecules with therapeutic and diagnostic applications, but they are primarily developed through immunization of camelids. This approach is not scalable by automation, not effective for non-immunogenic or toxic antigens, and prevents the use of modified scaffolds for altered pharmacokinetic properties. Synthetic libraries allow for pre-selection of a single domain framework tailored to its intended downstream use. One area of interest for these biologic vectors is radiopharmaceuticals. Ideal radiopharmaceutical pharmacokinetic properties differ from most traditional therapeutics, as short plasma circulation and rapid kidney clearance are necessary to avoid dose-limiting organ radiation. Although there are a growing number of nanobody radiopharmaceuticals in clinical trials, their frameworks and corresponding pharmacokinetic properties vary. One potential method for improving the development of novel single domain antibody radiopharmaceuticals is through synthetic libraries based on nanobodies with proven clinically acceptable pharmacokinetics. We developed a modular synthetic nanobody phage display vector based on the scaffold of the 2Rs15d nanobody that allows for manipulation of the binding and framework regions. Using this vector, we created a library of nanobodies with a randomized CDR2 containing over 1.7x106 unique sequences/{micro}L. As a proof-of-concept, we panned the library for nanobodies binding calreticulin (CALR), a protein critical in immunogenic cell death. One isolated clone, Cal3, has a measured affinity of 140 nM for CALR and is cross-reactive with mouse and human CALR. Using positron emission tomography (PET) imaging, the radiolabeled 64Cu-NOTA-Cal3 demonstrated CALR binding in vivo, representing the first reported synthetic nanobody characterized by PET imaging. This study demonstrates the feasibility of building and panning synthetic libraries for high-affinity radiopharmaceutical nanobodies as an alternative to immunized camelid libraries.

bioengineering↗

bioRxiv2022

Preclinical safety evaluation of continuous UV-A lighting in an operative setting

BackgroundGermicidal ultraviolet (UV-C) light has been shown as an effective modality for disinfection in laboratory settings and in the operative room. Traditionally, short-wavelength UV-C devices, which have previously been shown to cause DNA damage, are utilized only for disinfection in pre- and post-operative settings and are not continuously active during operations. Continuous use of intraoperative UV light can potentially decrease pathogens and subsequent surgical site infections (SSIs), which arise in approximately 5-15% of operative cases. SSIs are a significant determinant of patient morbidity, readmission rates, and overall cost. Therefore, a method of UV light disinfection with a low risk of DNA damage is needed so that greater antimicrobial protection can be afforded to patients during the entirety of their surgical procedures. A new disinfection device that harnesses longer-wavelength UV-A light to disinfect the surgical field throughout the entirety of the procedure, including pre- and post-operation, has been developed. MethodsThis study aimed to determine if intraoperatively administered UV-A light was safe, as defined by the minimal presence of DNA damage and safe amounts of reflection upon medical personnel. Using in vitro models, we examined the differential impacts of UV-C and UV-A light on DNA damage and repair pathways. In a murine model, we looked at the difference in production of DNA damage photoproducts between UV-A and UV-C exposure. ResultsOur results show UV-A light does not induce a significant amount of DNA damage at the cellular or tissue level. Furthermore, a preclinical porcine study showed that surgical personnel were exposed to safe levels of UV-A irradiance from an overhead UV-A light used during an operation. The amount of UV-A transmitted through surgical personal protective equipment (PPE) also remained within safe levels. ConclusionsIn conclusion, we found that UV-A may be a safe for intraoperative use.

molecular biology↗

bioRxiv2022

PKD-1 Signaling Is Required for the Maintenance of CSCs with Epithelial-mesenchymal Plasticity in Pancreatic Neuroendocrine Tumors

Pancreatic neuroendocrine tumors (pNETs) are extremely heterogeneous and highly vascularized neoplasms that arise from endocrine cells in the pancreas. pNETs harbor a subpopulation of stem cell-like cancer cells (cancer stem cells/CSCs), which contribute to intratumoral heterogeneity and promote tumor maintenance and recurrence. In this study we demonstrated that CSCs in human pNETs co-expressed PKD-1 and CD44. We further identified PKD-1 signaling as a critical pathway in the regulation of CSC maintenance in pNET cells. PKD-1 signaling regulated the expression of a CSC-related gene signature and promoted CSC self-renewal. Intriguingly, pharmacological or genetic disruption of PKD-1 signaling in human pNET cells impaired lysophosphatidic acid-induced expression of genes associated with epithelial to mesenchymal transition (EMT), specifically E-cadherin and vimentin. This study indicates that PKD-1 signaling is essential for the maintenance of a subpopulation of CSCs in pNETs at an intermediate state along the epithelial-mesenchymal spectrum, thereby leading to a CSC phenotype with plasticity and partial EMT. Inhibiting the PKD-1 pathway may facilitate the elimination of CSC subpopulations to curb pNET progression, therapeutic resistance and metastasis. Given that the signaling networks associated with CSC maintenance and EMT are complex and extend across multiple levels of gene regulation, this study provides insight into signaling regulation of partial EMT in determining CSC fate and aids in developing potential therapeutic strategies that target different subsets of CSCs in a variety of cancers.

cancer biology↗

bioRxiv2021

Cdk5 drives formation of heterogeneous pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors (PanNETs) are a heterogeneous population of neoplasms that arise from hormone-secreting islet cells of the pancreas and have increased markedly in incidence over the past four decades. Non-functional PanNETs, which occur more frequently than hormone-secreting tumors, are often not diagnosed until later stages of tumor development and have poorer prognoses. Development of successful therapeutics for PanNETs has been slow, partially due to a lack of diverse animal models for pre-clinical testing. Here, we report development of an inducible, conditional mouse model of PanNETs by using a bitransgenic system for regulated expression of the aberrant activator of Cdk5, p25, specifically in {beta}-islet cells. This model produces a heterogeneous population of PanNETs that includes a subgroup of well-differentiated, non-functional tumors. The utility of this model is enhanced by ability to form tumor-derived allografts. Production of these tumors demonstrates the causative potential of aberrantly active Cdk5 for generation of PanNETs. Further, we show that human PanNETs express Cdk5 pathway components, are dependent on Cdk5 for growth, and share genetic and transcriptional overlap with the INS-p25OE model. This new model of PanNETs will facilitate molecular delineation of Cdk5-dependent PanNETs and the development of new targeted therapeutics.

cancer biology↗