A ferritin-based COVID-19 nanoparticle vaccine that elicits robust, durable, broad-spectrum neutralizing antisera in non-human primates

While the rapid development of COVID-19 vaccines has been a scientific triumph, the need remains for a globally available vaccine that provides longer-lasting immunity against present and future SARS-CoV-2 variants of concern (VOCs). Here, we describe DCFHP, a ferritin-based, protein-nanoparticle vaccine candidate that, when formulated with aluminum hydroxide as the sole adjuvant (DCFHP-alum), elicits potent and durable neutralizing antisera in non-human primates against known VOCs, including Omicron BQ.1, as well as against SARS-CoV-1. Following a booster ~one year after the initial immunization, DCFHP-alum elicits a robust anamnestic response. To enable global accessibility, we generated a cell line that can enable production of thousands of vaccine doses per liter of cell culture and show that DCFHP-alum maintains potency for at least 14 days at temperatures exceeding standard room temperature. DCFHP-alum has potential as a once-yearly (or less frequent) booster vaccine, and as a primary vaccine for pediatric use including in infants

Chemical Modification-Assisted Bisulfite Sequencing (CAB-Seq) for 5‑Carboxylcytosine Detection in DNA

5-Methylcytosine (5mC) in DNA can be oxidized stepwise to 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC), and 5-carboxylcytosine (5caC) by the TET family proteins. Thymine DNA glycosylase can further remove 5fC and 5caC, connecting 5mC oxidation with active DNA demethylation. Here, we present a chemical modification-assisted bisulfite sequencing (CAB-Seq) that can detect 5caC with single-base resolution in DNA. We optimized 1-ethyl-3-[3-dimethylaminopropyl]­carbodiimide hydrochloride (EDC)-catalyzed amide bond formation between the carboxyl group of 5caC and a primary amine group. We found that the modified 5caC can survive the bisulfite treatment without deamination. Therefore, this chemical labeling coupled with bisulfite treatment provides a base-resolution detection and sequencing method for 5caC

Formulation development and comparability studies with an aluminum-salt adjuvanted SARS-CoV-2 Spike ferritin nanoparticle vaccine antigen produced from two different cell lines (Dataset)

The development of safe and effective second-generation COVID-19 vaccines to improve affordability and storage stability requirements remains a high priority to expand global coverage. In this report, we describe formulation development and comparability studies with a self-assembled SARS-CoV-2 spike ferritin nanoparticle vaccine antigen (called DCFHP), when produced in two different cell lines and formulated with an aluminum-salt adjuvant (Alhydrogel, AH). Varying levels of phosphate buffer altered the extent and strength of antigen-adjuvant interactions, and these formulations were evaluated for their (1) in vivo performance in mice and (2) in vitro stability profiles. Unadjuvanted DCFHP produced minimal immune responses while AH-adjuvanted formulations elicited greatly enhanced pseudovirus neutralization titers independent of ~100%, ~40% or ~10% of the DCFHP antigen adsorbed to AH. These formulations differed, however, in their in vitro stability properties as determined by biophysical studies and a competitive ELISA for measuring ACE2 receptor binding of AH-bound antigen. Interestingly, after one month of 4ºC storage, small increases in antigenicity with concomitant decreases in the ability to desorb the antigen from the AH were observed. Finally, we performed a comparability assessment of DCFHP antigen produced in Expi293 and CHO cells, which displayed expected differences in their N-linked oligosaccharide profiles. Despite consisting of different DCFHP glycoforms, these two preparations were highly similar in their key quality attributes including molecular size, structural integrity, conformational stability, binding to ACE2 receptor and mouse immunogenicity profiles. Taken together, these studies support future preclinical and clinical development of an AH-adjuvanted DCFHP vaccine candidate produced in CHO cells

Targeted Desialylation Overcomes Glyco-Immune Checkpoints and Potentiates the Anticancer Immune Response in Vivo

Currently approved immune checkpoint inhibitor (ICI) therapies targeting the PD-1 and CTLA-4 receptor pathways are powerful treatment options for certain cancers; however, the majority of patients across cancer types still fail to respond. Addressing alternative pathways that mediate immune suppression could enhance ICI efficacy. One such mechanism is the increase in sialic acid-containing proteins and lipids (sialoglycans) in malignancy, which recently has been shown to inhibit immune cell activation through multiple mechanisms including Siglec receptor binding, and therefore represents a targetable glyco-immune checkpoint. Here, we report the design of a trastuzumab- sialidase conjugate that potently and selectively strips diverse sialoglycans from breast cancer cells in vivo. In a syngeneic orthotopic HER2+ breast cancer model, targeted desialylation delayed tumor growth and enhanced immune cell infiltration and activation, leading to prolonged survival of mice with trastuzumab-resistant breast cancer. Thus, antibody-sialidase conjugates represent a promising modality for cancer immune therapy.</div

Mechanisms of innate and adaptive immunity to the Pfizer-BioNTech BNT162b2 vaccine

Despite the success of the BNT162b2 mRNA vaccine, the immunological mechanisms that underlie its efficacy are poorly understood. Here we analyzed the innate and adaptive responses to BNT162b2 in mice, and show that immunization stimulated potent antibody and antigen-specific T cell responses, as well as strikingly enhanced innate responses after secondary immunization, which was concurrent with enhanced serum interferon (IFN)-γ levels 1 d following secondary immunization. Notably, we found that natural killer cells and CD8+ T cells in the draining lymph nodes are the major producers of this circulating IFN-γ. Analysis of knockout mice revealed that induction of antibody and T cell responses to BNT162b2 was not dependent on signaling via Toll-like receptors 2, 3, 4, 5 and 7 nor inflammasome activation, nor the necroptosis or pyroptosis cell death pathways. Rather, the CD8+ T cell response induced by BNT162b2 was dependent on type I interferon-dependent MDA5 signaling. These results provide insights into the molecular mechanisms by which the BNT162b2 vaccine stimulates immune responses