Biology subjects

Joseph, R. A.

Publications and source records attributed to Joseph, R. A..

5 recordsLinked to original sources

bioRxiv2026

Fulfilling Koch-like postulates for fungal-animal mutualists: gallery and mycangial colonization by Xyleborus ambrosia symbiotic fungi

Fungal-animal mutualisms remain significantly understudied, yet they represent some of the most successful partnerships known in nature. Fungal farming ambrosia beetles cultivate a consortium of fungal partners that include obligate filamentous members and yeasts. These fungi are maintained in highly specialized insect organs, termed mycangia, and are cultivated as food along the beetle galleries elaborated within host trees. Here, we isolated fungi from the mycangia of Xyleborus affinis ambrosia beetles using both standard ethanol-wash and ethanol-free protocols. Omitting the ethanol wash significantly increased fungal recovery and diversity. We identify two previously described filamentous species, Raffaelea arxii and R. fusca, and the yeast, Ambrosiozyma monospora, together with two new filamentous fungi, Neocosmospora affinis and Graphium ambrosium, and two novel yeasts, Alloascoidea xylebori and Wickerhamomyces ambrosius, from both gallery walls and beetle mycangia. To meet Koch-like postulates, using mycangial colonization assays, we demonstrate that all seven fungal species were individually competent at colonizing aposymbiotic X. affinis mycangia, demonstrating each as viable symbionts. Our results show that ethanol-protocols can bias recovery of mycangial fungi, leading to underestimation of fungal diversity associated with ambrosia beetles. These findings provide a framework for improved characterization of ambrosia beetle-fungal mutualisms and experimental validation of fungal symbionts.

microbiology↗

bioRxiv2025

UV induces common cutaneous amyloid-like melanosomal protein aggregates

Misfolding of aggregation-prone proteins underpins diseases known as proteinopathies. One of these proteins, alpha-synuclein, is a component of aggregates in neurodegenerative conditions such as Parkinsons disease. The melanosomal protein PMEL, which forms physiologic amyloid scaffold structures on which melanin is organized in melanosomes, similarly ectopically accumulates in the dermis in many forms of cutaneous hyperpigmentation. Here, we demonstrate in a wide range of common clinical pigmentary disorders, as well as in primary melanocyte and mouse models examined by molecular, proteomic, and electron microscopic tools, that melanocytic alpha-synuclein is a prominent component of intracellular protein aggregates bound to similar proteins as in Parkinsons disease, as well as melanized extracellular protein deposits. Using the Real Time Quaking-Induced Conversion Assay (RT-QuIC), we demonstrate that UV induces misfolded melanosomal proteins to self-propagate, augmenting this pathology in prion-like fashion. CUT&RUN chromatin profiling and single-cell RNA-seq demonstrate that melanocytes utilize microphthalmia-associated transcription factor (MITF)-regulated autophagy to counteract protein aggregation, identifying aggregate removal as a core function of tanning. In contrast to extracellular aggregation, impaired intracellular aggregate removal contributes to melanocyte senescence, which conversely exacerbates chronic hypopigmentation and photoaging-related discoloration. These findings identify melanosomal proteinopathy as a common contributor to melanocyte dysfunction and suggest aggregate-focused management approaches.

molecular biology↗

bioRxiv2025

Anti-CD38-Targeted Piperazine-Derived Lipid Nanoparticles Overcome Hepatic Clearance for mRNA Delivery to Multiple Myeloma Cells In Vivo

Multiple myeloma (MM) is an incurable plasma cell malignancy characterized by clonal heterogeneity, immune evasion, and therapeutic resistance. Messenger RNA (mRNA) therapeutics offer programmable strategies to express therapeutic proteins and gene editors, but their efficacy is limited by poor extrahepatic delivery. To overcome these barriers, we developed a lipid nanoparticle (LNP) platform for targeted mRNA delivery to MM cells in vivo. Through combinatorial screening, we identified C16-O1, a piperazine-based ionizable lipid that efficiently transfects both CD138+ and therapy-resistant CD138-MM subclones. For tumor selectivity, LNPs were functionalized with an antibody fragment against CD38, a clinically validated MM antigen. Anti-CD38 LNPs reached the tumor-site and significantly reduced hepatic accumulation in murine xenografts. As an in vitro proof-of-concept, delivery of Cas9 mRNA and an IRF4-targeting guide RNA induced gene knockout, cell-cycle arrest, and lenalidomide sensitization. Together, these findings establish a robust framework for targeted mRNA delivery in MM and other hematologic malignancies.

bioengineering↗

bioRxiv2025

Lipid nanoparticle co-delivery of mRNA and a small molecule drug for oral cancer chemoimmunotherapy

Oral squamous cell carcinoma (OSCC) represents 90% of all head and neck cancers. Despite decades of research, the 5-year survival rate is 50%, and strikingly, the overall incidence rate is projected to increase by 30% in the next ten years, which will result in a sharp increase in mortality. Two fundamental aspects of OSCC are that it progresses via the inactivation and mutation of tumor suppressor (TS) genes and has a "cold" tumor immune microenvironment (TIME). A major barrier in the treatment of OSCC is the lack of novel therapies clinicians have at their disposal that are designed to disrupt tumor progression by reshaping the cold tumors into inflammatory "hot" tumors. To overcome these obstacles, we employed a lipid nanoparticle (LNP) that co-encapsulates p53 mRNA and the small molecule ciclopirox (CPX). We demonstrate that both drugs have innate chemotherapeutic properties by facilitating caspase activation. Moreover, these therapies can create a less immunosuppressive TIME in part by repolarizing tumor-associated macrophages (TAMs) to M1-like phenotypes. When formulated together, our platform provides an all-in-one approach for OSCC, effective in both p53-therapy-susceptible and p53-therapy-resistant models. Additionally, this work provides a template for a delivery platform capable of tackling multiple mechanisms of OSCC progression and survival.

bioengineering↗

bioRxiv2025

High-throughput in vivo screening using barcoded mRNA identifies lipid nanoparticles with extrahepatic tropism for cancer immunotherapy

Interest continues to grow in the use of mRNA vaccines for cancer immunotherapy. While effective for immunization against infectious diseases, current clinical lipid nanoparticle (LNP) formulations used for mRNA delivery suffer from off-target accumulation, poor immune transfection, and reactogenicity, limiting their application to cancer immunotherapy. Development of new mRNA LNPs is severely bottlenecked by the LNP discovery process, which is historically low-throughput due to reliance on low-plexity measurements. Here, we develop a next-generation high-throughput in vivo mRNA LNP screening platform based on barcoded mRNA (b-mRNA). Using this b-mRNA screening platform to simultaneously evaluate 122 LNPs, we identify novel LNP formulations capable of potent hepatic and extrahepatic transfection. We employ novel biochemical characterization techniques to analyze nanoparticle protein corona formation with single-particle resolution and gain insight into the influence of protein adsorption on hepatic and splenic transfection. We evaluate a lead LNP candidate for therapeutic cancer vaccination in a syngeneic mouse model of melanoma and demonstrate a significant reduction in tumor burden and increase in survival compared to a clinical mRNA LNP formulation. Together, our results demonstrate the value of advanced LNP screening and characterization techniques for the development of next-generation mRNA therapeutics and vaccines.

bioengineering↗