Ashley Utz

All Publications

• Generation of an inflammatory niche in a hydrogel depot through recruitment of key immune cells improves efficacy of mRNA vaccines. Science advances Meany, E. L., Klich, J. H., Jons, C. K., Mao, T., Chaudhary, N., Utz, A., Baillet, J., Song, Y. E., Saouaf, O. M., Ou, B. S., Williams, S. C., Eckman, N., Irvine, D. J., Appel, E. 2025; 11 (15): eadr2631

  Abstract

  Messenger RNA (mRNA) delivered in lipid nanoparticles (LNPs) rose to the forefront of vaccine candidates during the COVID-19 pandemic due to scalability, adaptability, and potency. Yet, there remain critical areas for improvements of these vaccines in durability and breadth of humoral responses. In this work, we explore a modular strategy to target mRNA/LNPs to antigen-presenting cells with an injectable polymer-nanoparticle (PNP) hydrogel technology, which recruits key immune cells and forms an immunological niche in vivo. We characterize this niche on a single-cell level and find it is highly tunable through incorporation of adjuvants like MPLAs and 3M-052. Delivering commercially available severe acute respiratory syndrome coronavirus 2 mRNA vaccines in PNP hydrogels improves the durability and quality of germinal center reactions, and the magnitude, breadth, and durability of humoral responses. The tunable immune niche formed within PNP hydrogels effectively skews immune responses based on encapsulated adjuvants, creating opportunities to precisely modulate mRNA/LNP vaccines for various indications from infectious diseases to cancers.

  View details for DOI 10.1126/sciadv.adr2631

  View details for PubMedID 40215318

  View details for PubMedCentralID PMC11988412

• Multilayered HIV-1 resistance in HSPCs through CCR5 Knockout and B cell secretion of HIV-inhibiting antibodies. Nature communications Feist, W. N., Luna, S. E., Ben-Efraim, K., Filsinger Interrante, M. V., Amorin, A., Johnston, N. M., Bruun, T. U., Utz, A., Ghanim, H. Y., Lesch, B. J., McLaughlin, T. M., Dudek, A. M., Porteus, M. H. 2025; 16 (1): 3103

  Abstract

  Allogeneic transplantation of CCR5 null hematopoietic stem and progenitor cells (HSPCs) is the only known cure for HIV-1 infection. However, this treatment is limited because of the rarity of CCR5-null matched donors, the morbidities associated with allogeneic transplantation, and the prevalence of HIV-1 strains resistant to CCR5 knockout (KO) alone. Here, we propose a one-time therapy through autologous transplantation of HSPCs genetically engineered ex vivo to produce both CCR5 KO cells and long-term secretion of potent HIV-1 inhibiting antibodies from B cell progeny. CRISPR-Cas9-engineered HSPCs engraft and reconstitute multiple hematopoietic lineages in vivo and can be engineered to express multiple antibodies simultaneously (in pre-clinical models). Human B cells engineered to express each antibody secrete neutralizing concentrations capable of inhibiting HIV-1 pseudovirus infection in vitro. This work lays the foundation for a potential one-time functional cure for HIV-1 through combining the long-term delivery of therapeutic antibodies against HIV-1 and the known efficacy of CCR5 KO HSPC transplantation.

  View details for DOI 10.1038/s41467-025-58371-8

  View details for PubMedID 40164595

  View details for PubMedCentralID 24285

• Development of Pan-Betacoronavirus Therapeutics for Future Pandemic Preparedness Utz, A., Thi Thuy Tien Nguyen, Weidenbacher, P. B., Kim, P. S. WILEY. 2024: 96-97

  View details for Web of Science ID 001437110900109

• Engineering a SARS-CoV-2 Vaccine Targeting the Receptor-Binding Domain Cryptic-Face via Immunofocusing. ACS central science Bruun, T. U., Do, J., Weidenbacher, P. A., Utz, A., Kim, P. S. 2024; 10 (10): 1871-1884

  Abstract

  The receptor-binding domain (RBD) of the SARS-CoV-2 spike protein is the main target of neutralizing antibodies. Although they are infrequently elicited during infection or vaccination, antibodies that bind to the conformation-specific cryptic face of the RBD display remarkable breadth of binding and neutralization across Sarbecoviruses. Here, we employed the immunofocusing technique PMD (protect, modify, deprotect) to create RBD immunogens (PMD-RBD) specifically designed to focus the antibody response toward the cryptic-face epitope recognized by the broadly neutralizing antibody S2X259. Immunization with PMD-RBD antigens induced robust binding titers and broad neutralizing activity against homologous and heterologous Sarbecovirus strains. A serum-depletion assay provided direct evidence that PMD successfully skewed the polyclonal antibody response toward the cryptic face of the RBD. Our work demonstrates the ability of PMD to overcome immunodominance and refocus humoral immunity, with implications for the development of broader and more resilient vaccines against current and emerging viruses with pandemic potential.

  View details for DOI 10.1021/acscentsci.4c00722

  View details for PubMedID 39463836

  View details for PubMedCentralID PMC11503491

• Engineering a SARS-CoV-2 Vaccine Targeting the Receptor-Binding Domain Cryptic-Face via Immunofocusing ACS CENTRAL SCIENCE Bruun, T. J., Do, J., Weidenbacher, P., Utz, A., Kim, P. S. 2024

  View details for DOI 10.1021/acscentsci.4c00722

  View details for Web of Science ID 001315141300001

• Design of universal Ebola virus vaccine candidates via immunofocusing. Proceedings of the National Academy of Sciences of the United States of America Xu, D., Powell, A. E., Utz, A., Sanyal, M., Do, J., Patten, J. J., Moliva, J. I., Sullivan, N. J., Davey, R. A., Kim, P. S. 2024; 121 (7): e2316960121

  Abstract

  The Ebola virus causes hemorrhagic fever in humans and poses a significant threat to global public health. Although two viral vector vaccines have been approved to prevent Ebola virus disease, they are distributed in the limited ring vaccination setting and only indicated for prevention of infection from orthoebolavirus zairense (EBOV)-one of three orthoebolavirus species that have caused previous outbreaks. Ebola virus glycoprotein GP mediates viral infection and serves as the primary target of neutralizing antibodies. Here, we describe a universal Ebola virus vaccine approach using a structure-guided design of candidates with hyperglycosylation that aims to direct antibody responses away from variable regions and toward conserved epitopes of GP. We first determined the hyperglycosylation landscape on Ebola virus GP and used that to generate hyperglycosylated GP variants with two to four additional glycosylation sites to mask the highly variable glycan cap region. We then created vaccine candidates by displaying wild-type or hyperglycosylated GP variants on ferritin nanoparticles (Fer). Immunization with these antigens elicited potent neutralizing antisera against EBOV in mice. Importantly, we observed consistent cross-neutralizing activity against Bundibugyo virus and Sudan virus from hyperglycosylated GP-Fer with two or three additional glycans. In comparison, elicitation of cross-neutralizing antisera was rare in mice immunized with wild-type GP-Fer. These results demonstrate a potential strategy to develop universal Ebola virus vaccines that confer cross-protective immunity against existing and emerging filovirus species.

  View details for DOI 10.1073/pnas.2316960121

  View details for PubMedID 38319964

• Vaccine design via antigen reorientation. Nature chemical biology Xu, D., Carter, J. J., Li, C., Utz, A., Weidenbacher, P. A., Tang, S., Sanyal, M., Pulendran, B., Barnes, C. O., Kim, P. S. 2024

  Abstract

  A major challenge in creating universal influenza vaccines is to focus immune responses away from the immunodominant, variable head region of hemagglutinin (HA-head) and toward the evolutionarily conserved stem region (HA-stem). Here we introduce an approach to control antigen orientation via site-specific insertion of aspartate residues that facilitates antigen binding to alum. We demonstrate the generalizability of this approach with antigens from Ebola, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza viruses and observe enhanced neutralizing antibody responses in all cases. We then reorient an H2 HA in an 'upside-down' configuration to increase the exposure and immunogenicity of HA-stem. The reoriented H2 HA (reoH2HA) on alum induced stem-directed antibodies that cross-react with both group 1 and group 2 influenza A subtypes. Electron microscopy polyclonal epitope mapping (EMPEM) revealed that reoH2HA (group 1) elicits cross-reactive antibodies targeting group 2 HA-stems. Our results highlight antigen reorientation as a generalizable approach for designing epitope-focused vaccines.

  View details for DOI 10.1038/s41589-023-01529-6

  View details for PubMedID 38225471

  View details for PubMedCentralID 9345323

• Design of universal Ebola virus vaccine candidates via immunofocusing. bioRxiv : the preprint server for biology Xu, D., Powell, A. E., Utz, A., Sanyal, M., Do, J., Patten, J. J., Moliva, J. I., Sullivan, N. J., Davey, R. A., Kim, P. S. 2023

  Abstract

  Ebola virus causes hemorrhagic fever in humans and poses a significant threat to global public health. Although two viral vector vaccines have been approved to prevent Ebola virus disease, they are distributed in the limited ring vaccination setting and only indicated for prevention of infection from orthoebolavirus zairense (EBOV) - one of three orthoebolavirus species that have caused previous outbreaks. Ebola virus glycoprotein GP mediates viral infection and serves as the primary target of neutralizing antibodies. Here we describe a universal Ebola virus vaccine approach using structure-guided design of candidates with hyperglycosylation that aims to direct antibody responses away from variable regions and toward conserved epitopes of GP. We first determined the hyperglycosylation landscape on Ebola virus GP and used that to generate hyperglycosylated GP variants with two to four additional glycosylation sites to mask the highly variable glycan cap region. We then created vaccine candidates by displaying wild-type or hyperglycosylated GP variants on ferritin nanoparticles (Fer). Immunization with these antigens elicited potent neutralizing antisera against EBOV in mice. Importantly, we observed consistent cross-neutralizing activity against Bundibugyo virus and Sudan virus from hyperglycosylated GP-Fer with two or three additional glycans. In comparison, elicitation of cross-neutralizing antisera was rare in mice immunized with wild-type GP-Fer. These results demonstrate a potential strategy to develop universal Ebola virus vaccines that confer cross-protective immunity against existing and emerging filovirus species.Ebola virus outbreaks cause hemorrhagic fever with high mortality rates. Current viral vaccines require cold-chain storage and are distributed in limited ring vaccination settings. They are only indicated for protection against orthoebolavirus zairense (EBOV), one of three human-pathogenic Ebola virus species. Here we harness hyperglycosylation as an immunofocusing approach to design universal Ebola virus vaccine candidates based on Ebola virus glycoprotein (GP) displayed on ferritin nanoparticles (Fer). Compared with wild-type GP-Fer, immunization with hyperglycosylated GP-Fer elicited potently neutralizing antisera against EBOV, and more importantly, consistent cross-neutralizing activity against the other two orthoebolavirus species. Our work shows that immunofocusing antibody responses toward conserved and neutralizing epitopes of GP represents a promising strategy for vaccine design against antigenically diverse Ebola virus species.

  View details for DOI 10.1101/2023.10.14.562364

  View details for PubMedID 37904982

  View details for PubMedCentralID PMC10614775

• Designing epitope-focused vaccines via antigen reorientation. bioRxiv : the preprint server for biology Xu, D., Li, C., Utz, A., Weidenbacher, P. A., Tang, S., Sanyal, M., Pulendran, B., Kim, P. S. 2022

  Abstract

  A major challenge in vaccine development, especially against rapidly evolving viruses, is the ability to focus the immune response toward evolutionarily conserved antigenic regions to confer broad protection. For example, while many broadly neutralizing antibodies against influenza have been found to target the highly conserved stem region of hemagglutinin (HA-stem), the immune response to seasonal influenza vaccines is predominantly directed to the immunodominant but variable head region (HA-head), leading to narrow-spectrum efficacy. Here, we first introduce an approach to controlling antigen orientation based on the site-specific insertion of short stretches of aspartate residues (oligoD) that facilitates antigen-binding to alum adjuvants. We demonstrate the generalizability of this approach to antigens from the Ebola virus, SARS-CoV-2, and influenza and observe enhanced antibody responses following immunization in all cases. Next, we use this approach to reorient HA in an "upside down" configuration, which we envision increases HA-stem exposure, therefore also improving its immunogenicity compared to HA-head. When applied to HA of H2N2 A/Japan/305/1957, the reoriented H2 HA (reoH2HA) on alum induced a stem-directed antibody response that cross-reacted with both group 1 and 2 influenza A HAs. Our results demonstrate the possibility and benefits of antigen reorientation via oligoD insertion, which represents a generalizable immunofocusing approach readily applicable for designing epitope-focused vaccine candidates.GRAPHICAL ABSTRACT: Seasonal influenza vaccines induce a biased antibody response against the variable head of hemagglutinin, whereas conserved epitopes on the stem are a target for universal vaccines. Here we show that reorienting HA in an "upside-down" configuration sterically occludes the head and redirects the antibody response to the more exposed stem, thereby inducing broad cross-reactivity against hemagglutinins from diverse influenza strains.

  View details for DOI 10.1101/2022.12.20.521291

  View details for PubMedID 36597536

• Toward Point-of-Care Detection of Mycobacterium tuberculosis: A Brighter Solvatochromic Probe Detects Mycobacteria within Minutes. JACS Au Kamariza, M., Keyser, S. G., Utz, A., Knapp, B. D., Ealand, C., Ahn, G., Cambier, C. J., Chen, T., Kana, B., Huang, K. C., Bertozzi, C. R. 2021; 1 (9): 1368-1379

  Abstract

  There is an urgent need for point-of-care tuberculosis (TB) diagnostic methods that are fast, inexpensive, and operationally simple. Here, we report on a bright solvatochromic dye trehalose conjugate that specifically detects Mycobacterium tuberculosis (Mtb) in minutes. 3-Hydroxychromone (3HC) dyes, known for having high fluorescence quantum yields, exhibit shifts in fluorescence intensity in response to changes in environmental polarity. We synthesized two analogs of 3HC-trehalose conjugates (3HC-2-Tre and 3HC-3-Tre) and determined that 3HC-3-Tre has exceptionally favorable properties for Mtb detection. 3HC-3-Tre-labeled mycobacterial cells displayed a 10-fold increase in fluorescence intensity compared to our previous reports on the dye 4,4-N,N-dimethylaminonapthalimide (DMN-Tre). Excitingly, we detected fluorescent Mtb cells within 10 min of probe treatment. Thus, 3HC-3-Tre permits rapid visualization of mycobacteria that ultimately could empower improved Mtb detection at the point-of-care in low-resource settings.

  View details for DOI 10.1021/jacsau.1c00173

  View details for PubMedID 34604847

• Computation-Guided Rational Design of a Peptide Motif That Reacts with Cyanobenzothiazoles via Internal Cysteine-Lysine Relay JOURNAL OF ORGANIC CHEMISTRY Keyser, S. L., Utz, A., Bertozzi, C. R. 2018; 83 (14): 7467–79

  Abstract

  Site-selective protein modification based on covalent reactions of peptide tags and small molecules is a key capability for basic research as well as for the development of new therapeutic bioconjugates. Here, we describe the computation-guided rational design of a cysteine- and lysine-containing 11-residue peptide sequence that reacts with 2-cyanobenzothiazole (CBT) derivatives. Our data show that the cysteine residue reversibly reacts with the nitrile group on the CBT moiety to form an intermediate thioimidate, which undergoes irreversible SN transfer to the lysine residue, yielding an amidine-linked product. The concepts outlined herein lay a foundation for future development of peptide tags in the context of site-selective modification of lysine residues within engineered microenvironments.

  View details for DOI 10.1021/acs.joc.8b00625

  View details for Web of Science ID 000439761100020

  View details for PubMedID 29771122

• Synthesis of solvatochromic probes to label the mycobacterial cell wall and their use in studies of host-pathogen interactions Keyser, S., Utz, A., Kamariza, M., Bertozzi, C. AMER CHEMICAL SOC. 2017

  View details for Web of Science ID 000429556702049

• Synthesis of solvatochromic probes to study the effect of host microenvironment on mycobacterial cell wall dynamics during infection Keyser, S., Utz, A., Bertozzi, C. AMER CHEMICAL SOC. 2017

  View details for Web of Science ID 000430568501010

• Synthesis of solvatochromic probes to label the mycobacterial cell wall Utz, A., Keyser, S., Bertozzi, C. AMER CHEMICAL SOC. 2017

  View details for Web of Science ID 000430568504214