Biology subjects

Denzin, L. K.

Publications and source records attributed to Denzin, L. K..

4 recordsLinked to original sources

bioRxiv2025

Evaluation of Antigen Expression and Early Immune Response following Cutaneous Suction-mediated DNA Delivery

Suction-based in vivo cutaneous DNA transfection is a newly developed, cost-effective method that produces high transfection efficiency. This method has shown robust immunogenic responses following SARS-CoV-2 DNA vaccination in both pre-clinical studies and clinical trials. The current work investigates suction-based transfection and immune activation on a detailed, cellular level. The spatiotemporal patterns of antigen expression in rat skin following suction-induced delivery of a pEGFP-N1 plasmid and a SARS-CoV-2 DNA vaccine are evaluated via immunofluorescence staining, which demonstrates early and prolonged expression. The epidermis is identified as the primary location of transfection, and the transfected cells are primarily epidermal keratinocytes. Early immune response is assessed by detection of antigen presenting cells (APCs) following suction-induced DNA vaccination.

bioengineering↗

bioRxiv2025

Cutaneous suction-mediated transfection in mice for delivery of DNA-encoded vaccines and proteins

An important step to fulfill the functionalities of DNA vaccines and therapeutics is transfection in vivo to produce the encoded antigens or therapeutic proteins. A cutaneous suction-based method has demonstrated effectiveness in many animal models and has been successfully applied in human clinical trials, but has not been extended to mouse models, where numerous disease models, transgenic strains, and murine-specific reagents exist. The current work establishes and optimizes methods for cutaneous suction-mediated DNA transfection in mice. By adapting a smaller cup diameter and smaller injection volume, the challenges of skin hyperelasticity and decreased skin thickness can be effectively addressed, and vaccinating mice with the GLS-5310 SARS-CoV-2 DNA vaccine yielded high levels of binding antibody and T cell responses. Additionally, suction following injection of a novel pVAX1-based expression vector yielded systemic levels of a SEAP transgene. Thus, suction-mediated delivery of nucleic acid-based therapies and vaccines can be a valuable tool for the study in pre-clinical mouse models.

bioengineering↗

bioRxiv2023

A SARS-CoV-2 vaccine designed for manufacturability results in unexpected potency and non-waning humoral response

The rapid development of several highly efficacious SARS-CoV-2 vaccines was an unprecedented scientific achievement that saved millions of lives. However, now that SARS-CoV-2 is transitioning to the endemic stage, there exists an unmet need for new vaccines that provide durable immunity, protection against variants, and can be more easily manufactured and distributed. Here we describe a novel protein component vaccine candidate, MT-001, based on a fragment of the SARS-CoV-2 spike protein that encompasses the receptor binding domain (RBD). Mice and hamsters immunized with a prime-boost regimen of MT-001 demonstrated extremely high anti-spike IgG titers, and remarkably this humoral response did not appreciably wane for up to 12 months following vaccination. Further, virus neutralization titers, including titers against variants such as Delta and Omicron BA.1, remained high without the requirement for subsequent boosting. MT-001 was designed for manufacturability and ease of distribution, and we demonstrate that these attributes are not inconsistent with a highly immunogenic vaccine that confers durable and broad immunity to SARS-CoV-2 and its emerging variants. These properties suggest MT-001 could be a valuable new addition to the toolbox of SARS-CoV-2 vaccines and other interventions to prevent infection and curtail additional morbidity and mortality from the ongoing worldwide pandemic.

immunology↗

bioRxiv2019

Deletion of mouse Setd4 promotes the recovery of hematopoietic failure.

Acquired hematopoietic failure is commonly caused by therapeutic and accidental exposure to toxic agents to the bone marrow (BM). Efficient recovery from the BM failure is not only dictated by the intrinsic sensitivity and proliferation capacity of the hematopoietic stem and progenitor cells, but also nourished by the BM environment niche. Identification of genetic factors that improve the recovery from hematopoietic failure is essential. Vertebrate SETD4 is a poorly characterized, putative non-histone methyl-transferase whose physiological substrates have not yet been fully identified. By inducing Setd4 deletion in adult mice, we found that loss of Setd4 improved the survival of whole body irradiation induced BM failure. This was associated with improved recoveries of long-term and short-term hematopoietic stem cells (HSC), and early progenitor cells. BM transplantation analyses surprisingly showed that the improved recovery was not due to a radiation resistance of the Setd4 deficient HSC, but that Setd4 deficient HSC were actually more sensitive to radiation. However, the Setd4 deficient mice were better recipients for allogeneic HSC transplantation. Furthermore, there was an enhanced splenic erythropoiesis in Setd4 deficient mice. These findings not only revealed a previously unrecognized role of the Setd4 as a unique modulator of hematopoiesis, but also underscored the critical role of the BM niche in the recovery of hematopoietic failure. These studies also implicated Setd4 as a potential target for therapeutic inhibition to improve the conditioning of the BM niche prior to allogeneic transplantation. Key pointsO_LIDeletion of Setd4 in adult mice improved the survival from hematopoietic failure. C_LIO_LISetd4 deficiency sensitized HSCs to radiation, but improved bone marrow environment niche. C_LIO_LIThe study suggests that SETD4 as a potential inhibitory target to improve bone marrow niche function for recovery of bone marrow failure. C_LI

developmental biology↗