Biology subjects

Cohen, A. A.

Publications and source records attributed to Cohen, A. A..

At least 19 recordsLinked to original sources

bioRxiv2026

Duality Vaccination through Nanodesign of Click-Ligated B-Cell Inhibitory Receptor Bridging

Synthesis of precise and robust molecular architectures is critical to harness the power of the immune system. The dimensions, rigidity and multivalency of nanoparticles contribute to eliciting high levels of antibodies from vaccination. However, antibodies vary hugely in quality: some antibodies are highly effective at neutralizing pathogens, while others provide little or no benefit. Here we establish switchable and modular platforms for protein and nanoparticle assembly that program the target of antibody responses. We introduce Duality vaccination: the simultaneous delivery of activating and inhibitory stimuli for focusing immune responses. To construct activatory immunogens, we employ click biology with spontaneous amidation to functionalize plug-and-display self-assembling porous dodecahedral nanocages. We construct inhibitory immunogens using SpyMask protease-gated bispecific assembly, ligating the antigen to binders that bridge the B cell receptor to immune checkpoint receptors. This dual immunogen architecture tailors the elicited antibodies to down-modulate undesired B cell responses. We establish the effect of temporal and spatial separation of activatory and inhibitory immunogen delivery. We further explore sensitivity to valency, linker flexibility and adjuvant delivery, employing model targets and coronavirus antigens. Dual programmable functionalization identifies key nanodesign features to control in vivo outputs, providing logic-gating towards urgent challenges in the creation of protective vaccines.

synthetic biology↗

bioRxiv2026

DE-SWAN analysis of biomarker trajectories over the life course is highly sensitive to age distribution and model parameterization

DE-SWAN is a commonly used method to study how large ensembles of omics biomarkers change across the life course. It has been used to demonstrate apparent repeated accelerations and decelerations of aging rates across the life course, including 2-3 peaks of aging-related changes. This result contradicts what is expected based on the demography of aging and known biological mechanisms. Here, we use simulations to study the robustness of DE-SWAN to the age distribution of the study sample and to choice of window size. We show that under many realistic scenarios, DE-SWAN is highly sensitive to factors unrelated to the underlying rates of change in aging biology. This calls into question the results of previous analyses that have attributed DE-SWAN peaks to acceleration and deceleration of aging. We conclude that the method is unreliable for studying rates of change across the life course under most circumstances.

bioinformatics↗

bioRxiv2025

Development of a Recombinant Single-Cycle Influenza Viral Vector as an Intranasal Vaccine against SARS-CoV-2 and SARS-like Betacoronaviruses

The COVID-19 pandemic has demonstrated the detrimental potential of zoonotic coronavirus transmission to human populations. Effective vaccines capable of eliciting immunity to SARS-CoV-2 have been pivotal in mitigating the spread of the virus. In this study, we describe the generation of a non-replicating pseudotyped influenza A virus (S-FLU), where the native haemagglutinin (HA) sequence is replaced with the coding sequence of either a membrane-anchored form (TM) or secretory form (Sec) of the receptor-binding domain (RBD) of the ancestral SARS-CoV-2 Wuhan (S-RBD Wuhan). We showed that both S-RBD-TM and S-RBD-Sec viruses can be generated via reverse genetics and grown to high titre. Intranasal immunisation in mice with S-RBD-TM elicits robust serum binding and neutralisation activity against SARS-CoV-2, superior to S-RBD-Sec. Furthermore, we demonstrate that a heterologous prime-boost immunisation regime in mice with S-RBD-TM Wuhan and S-RBD-TM BM48-31 (a distant Clade 3 SARS-like betacoronavirus (sarbecovirus)) increases antibody breadth against mismatched sarbecoviruses compared to homologous prime-boost with S-RBD-TM Wuhan. These results suggest that S-RBD-TM is a promising intranasal vaccine candidate against SARS-CoV-2 and may offer potential as a broadly protective sarbecovirus vaccine.

immunology↗

bioRxiv2025

mRNA delivery of genetically encoded mosaic-8 pan-sarbecovirus RBD vaccines

Effective pan-sarbecovirus vaccines could prevent future zoonotic spillovers of SARS-like betacoronaviruses. We previously developed protein-based mosaic-8 nanoparticles displaying eight diverse sarbecovirus RBDs, either individually (mosaic-8 RBD-NPs) or as two "quartets" of four tandemly-arranged RBDs (dual-quartet RBD-NPs), which elicited broadly cross-reactive antibodies but require multi-component manufacturing. Here, we address scalability challenges by extending the mosaic-8 concept to mRNA by encoding membrane-bound RBD quartets as dual-quartet RBD-mRNA and dual-quartet RBD-EABR-mRNA, the latter leveraging ESCRT- and ALIX-binding region (EABR) technology for immunogen display on cell surfaces and secreted virus-like particles. Compared with protein-based mosaic-8 immunogens, mRNA-encoded mosaic-8 vaccines induced equivalent or enhanced antibody breadth, neutralization potencies, T-cell responses, and targeting of conserved RBD epitopes. In addition, mRNA-encoded mosaic-8 vaccines elicited more balanced IgG subclass profiles and increased Fc{gamma} receptor-binding IgGs, consistent with potentially superior Fc effector functions. These findings demonstrate successful translation of mosaic-8 RBD-NPs into mRNA/EABR-mRNA vaccines, enabling scalable manufacturing and improving protection against future sarbecovirus outbreaks. Finally, our newly developed technique, Systems Serology-Polyclonal Epitope Mapping (SySPEM), revealed distinct IgG-subclass-specific epitope signatures across mRNA, EABR-mRNA, and protein vaccines, demonstrating that the mode of antigen display can shape epitope recognition. SummaryWe translated a pan-sarbecovirus RBD vaccine from protein nanoparticles to scalable mRNA and EABR-mRNA platforms encoding RBD quartets. Compared with protein-based immunogens, mRNA-based vaccines matched or improved antibody breadth, T-cell responses, Fc functionality, and conserved epitope targeting. A newly-developed Systems Serology-Polyclonal Epitope Mapping (SySPEM) technique revealed that antigen presentation modality shapes IgG subclass-specific epitope recognition.

immunology↗

bioRxiv2025

Evidence for an energetic trade-off model linking inflammaging and immunosenescence in the US Health and Retirement Study and UK Biobank

Later life is characterized by the development of chronic inflammation, termed inflammaging, alongside changes in immune cell profiles, or immunosenescence. While these features contribute to health risk, they have also been interpreted as adaptive remodeling of the immune system in response to accumulating somatic damage. Here we consider a recently developed theoretical framework to understand these processes as interrelated: the Brain-Body Energy Conservation model of aging. This model views functional declines, such as immunosenescence, as part of an energy conserving response to the rising energy expenditure of inflammaging. This response promotes short term survival against somatic damage at the expense of future health risk. For example, naive T cells, which enhance defense against future infections, decline with age. We find evidence consistent with this model in the US Health and Retirement Study (HRS) and UK Biobank (UKB). TNFR1, a key marker of inflammaging, mediated 10% and 5% of the age-related declines in naive CD4T and CD8T cells respectively in the HRS (n = 8,261). Consistent with an impaired immune response to future infections, TNFR1 also mediated 16% of the age-related increased risk of hospitalization or death from COVID-19 in the UKB (n = 522 hospitalized or died, full sample n = 40,638). GDF15, which is produced in response to metabolic stress and has been found to induce immune tolerance in response to chronic inflammation, mediated 28% of the TNFR1-related COVID-19 health risk, as well as 38% of the age-related increased risk independent of TNFR1.

evolutionary biology↗

bioRxiv2025

Bivalent mRNA booster encoding virus-like particles elicits potent polyclass RBD antibodies in pre-vaccinated mice

mRNA vaccines emerged as a leading vaccine technology during the COVID-19 pandemic. However, their sustained protective efficacies were limited by relatively short-lived antibody responses and the emergence of SARS-CoV-2 variants, necessitating frequent and variant-updated boosters. We recently developed the ESCRT- and ALIX-binding region (EABR) mRNA vaccine platform, which encodes engineered immunogens that induce budding of enveloped virus-like particles (eVLPs) from the plasma membrane, thereby resulting in presentation of immunogens on cell surfaces and eVLPs. Prior studies showed that spike (S)-EABR mRNA-LNP immunizations elicited enhanced neutralizing antibody responses against ancestral and variant SARS-CoV-2 compared with conventional S mRNA-LNP in naive mice, but the effectiveness of S-EABR mRNA-LNP boosters in the context of pre-existing immunity has not been investigated. Here, we evaluated monovalent Wuhan-Hu-1 (Wu1) and bivalent (Wu1/BA.5) S-EABR mRNA-LNP boosters in mice pre-vaccinated with conventional Wu1 S mRNA-LNP. Compared to conventional S mRNA-LNP boosters, the EABR approach enhanced monovalent and bivalent mRNA-LNP booster-induced neutralizing responses against Omicron subvariants BA.1, BA.5, BQ.1.1, and XBB.1, with bivalent S-EABR mRNA-LNP consistently eliciting the highest titers. Epitope mapping of polyclonal antisera by deep mutational scanning revealed that bivalent S-EABR mRNA-LNP boosted diverse "polyclass" anti-receptor-binding domain (RBD) responses, suggesting balanced targeting of multiple RBD epitope classes. In contrast, monovalent S, bivalent S, and monovalent S-EABR mRNA-LNP boosters elicited less diverse polyclonal serum responses primarily targeting immunodominant RBD epitopes. Cryo-EM structures demonstrated that bivalent mRNA immunizations promote S heterotrimer formation, potentially enhancing bivalent S-EABR mRNA-LNP booster-induced antibody breadth and polyclass epitope targeting by activating cross-reactive B cells through intra-S crosslinking. These findings support the future design of bivalent or multivalent S-EABR mRNA-LNP boosters as a promising strategy to confer broader, and therefore potentially more durable, protection against emerging SARS-CoV-2 variants and other rapidly evolving viruses.

immunology↗

bioRxiv2025

Single administration of mosaic-8b RBD-nanoparticle vaccine prepared with atomic layer deposition technology elicits broadly neutralizing anti-sarbecovirus responses

Atomic layer deposition (ALD), a new vaccine technology, permits multiple dosing with a single administration by pulsatile release of one or more immunogens. We evaluated ALD delivery of mosaic-8b [60-mer nanoparticles presenting 8 different SARS-like betacoronavirus (sarbecovirus) receptor-binding domains (RBDs)] that elicits broadly cross-reactive antibodies and protects against mismatched sarbecoviruses not represented by RBDs on mosaic-8b. Compared with conventional prime-boost immunizations, ALD-delivered mosaic-8b RBD-nanoparticles elicited antibodies in both naive and pre-vaccinated mice with improved mismatched binding and neutralization. Results of RBD epitope mapping of serum antibodies from ALD-delivered mosaic-8b were consistent with broader coverage of RBD epitopes compared to conventional immunizations, and systems serology revealed distinct IgG subclass and Fc{gamma}R-binding IgG distributions. These results suggest that ALD is a promising technology for use with mosaic-8b RBD-nanoparticle vaccines to protect against future sarbecovirus spillovers and support applications for ALD vaccine delivery to elicit cross-reactive antibodies against rapidly mutating or diverse pathogens.

immunology↗

bioRxiv2025

Mapping the GDF15 Arm of the Integrated Stress Response in Human Cells and Tissues

Mitochondrial stress activates the integrated stress response (ISR) and triggers cell-cell communication through the secretion of the metabokine growth differentiation factor 15 (GDF15). However, the gene network underlying the ISR remains poorly defined, particularly across metabolically diverse cellular states and tissues. Using RNAseq data from fibroblasts subjected to eleven metabolic perturbations, including genetic and pharmacological mitochondrial OxPhos defects, we showed that the ISR has multiple arms and developed an ISRGDF15 index quantifying the GDF15 arm of ISR activation in human cells. The ISRGDF15 index was validated using optogenetic activation of the ISR protein kinase R (PKR) in a stable cell line, demonstrating its rapid kinetics preceding to GDF15 gene expression. We then deployed the ISRGDF15 index across 44 postmortem human tissues, reporting that the ISRGDF15 was upregulated in the heart of individuals who died of an acute cause in the emergency room, whereas it was preferentially upregulated in the brain of individuals who died as inpatients after protracted hospital stays. ISRGDF15 was also moderately, positively correlated with age across all tissues. These data highlight multiple distinct ISR pathways and clarify which genes are related to the GDF15 arm of the ISR, yielding an ISRGDF15 index that can be used to investigate tissue-specific and age-related ISR activation in both in vitro cultures and human tissues. Ultimately, we expand our knowledge of the GDF15 arm of the ISR in humans, show its inducibility by the ISR kinase PKR, and demonstrate its applicability to detect ISR activation in specific human tissues.

cell biology↗

bioRxiv2025

Cross-reactive sarbecovirus antibodies induced by mosaic RBD-nanoparticles

Broad immune responses are needed to mitigate viral evolution and escape. To induce antibodies against conserved receptor-binding domain (RBD) regions of SARS-like betacoronavirus (sarbecovirus) spike proteins that recognize SARS-CoV-2 variants of concern and zoonotic sarbecoviruses, we developed mosaic-8b RBD-nanoparticles presenting eight sarbecovirus RBDs arranged randomly on a 60-mer nanoparticle. Mosaic-8b immunizations protected animals from challenges from viruses whose RBDs were matched or mismatched to those on nanoparticles. Here, we describe neutralizing mAbs isolated from mosaic-8b-immunized rabbits, some on par with Pemgarda, the only currently FDA-approved therapeutic mAb. Deep mutational scanning, in vitro selection of spike resistance mutations, and single-particle cryo-electron microscopy structures of spike-antibody complexes demonstrated targeting of conserved RBD epitopes. Rabbit mAbs included critical D-gene segment RBD-recognizing features in common with human anti-RBD mAbs, despite rabbit genomes lacking an equivalent human D-gene segment, thus demonstrating that the immune systems of humans and other mammals can utilize different antibody gene segments to arrive at similar modes of antigen recognition. These results suggest that animal models can be used to elicit anti-RBD mAbs with similar properties to those raised in humans, which can then be humanized for therapeutic use, and that mosaic RBD-nanoparticle immunization coupled with multiplexed screening represents an efficient way to generate and select broadly cross-reactive therapeutic pan-sarbecovirus and pan-SARS-CoV-2 variant mAbs. Significance StatementSARS-CoV-2 variants and potential zoonotic sarbecovirus infections continue to threaten human health. Anti-SARS-CoV-2 mAbs that recognize conserved epitopes could be used prophylactically or therapeutically. We present approaches to elicit and identify cross-reactive mAbs using immunizations in animals with mosaic RBD-nanoparticles. We show that human and other mammalian immune systems can utilize different antibody gene segments to arrive at similar modes of antigen recognition, underscoring the flexibility of mammalian antibody repertoires and suggesting that experimental animals can be used to generate therapeutically-useful cross-reactive anti-RBD mAbs. The combination of mosaic-8b RBD-nanoparticles to focus the immune response and a multiplexed assay to select cross-reactive mAbs can be applied at larger scale, or against other pathogens, to identify mAbs of therapeutic and scientific potential.

immunology↗

bioRxiv2024

Brain-body mitochondrial distribution patterns lack coherence and point to tissue-specific and individualized regulatory mechanisms

Energy transformation capacity is generally assumed to be a coherent individual trait driven by genetic and environmental factors. This predicts that some individuals should have high and others low mitochondrial oxidative phosphorylation (OxPhos) capacity across organ systems. Here, we test this assumption using multi-tissue molecular and enzymatic activities in mice and humans. Across up to 22 mouse tissues, neither mitochondrial OxPhos capacity nor mtDNA density were correlated between tissues (median r = -0.01-0.16), indicating that animals with high mitochondrial capacity in one tissue can have low capacity in other tissues. Similarly, the multi-tissue correlation structure of RNAseq-based indices of mitochondrial gene expression across 45 tissues from 948 women and men (GTEx) showed small to moderate coherence between only some tissues (regions of the same brain), but not between brain-body tissue pairs in the same person (median r = 0.01). Mitochondrial DNA copy number (mtDNAcn) also lacked coherence across organs and tissues. Mechanistically, tissue-specific differences in mitochondrial gene expression were attributable in part to i) tissue-specific activation of canonical energy sensing pathways including the transcriptional coactivator PGC-111 and the integrated stress response (ISR), and ii) proliferative activity across tissues. Finally, we identify subgroups of individuals with high mitochondrial gene expression in some tissues (e.g., heart) but low expression in others (e.g., skeletal muscle) who display different clinical phenotypic patterns. Taken together, these data raise the possibility that tissue-specific energy sensing pathways may contribute to the idiosyncratic mitochondrial distribution patterns associated with the inter-organ heterogeneity and phenotypic diversity among individuals.

cell biology↗

bioRxiv2024

Designed mosaic nanoparticles enhance cross-reactive immune responses in mice

Using computational methods, we designed 60-mer nanoparticles displaying SARS-like betacoronavirus (sarbecovirus) receptor-binding domains (RBDs) by (i) creating RBD sequences with 6 mutations in the SARS-COV-2 WA1 RBD that were predicted to retain proper folding and abrogate antibody responses to variable epitopes (mosaic-2COMs; mosaic-5COM), and (ii) selecting 7 natural sarbecovirus RBDs (mosaic-7COM). These antigens were compared with mosaic-8b, which elicits cross-reactive antibodies and protects from sarbecovirus challenges in animals. Immunizations in naive and COVID-19 pre-vaccinated mice revealed that mosaic-7COM elicited higher binding and neutralization titers than mosaic-8b and related antigens. Deep mutational scanning showed that mosaic-7COM targeted conserved RBD epitopes. Mosaic-2COMs and mosaic-5COM elicited higher titers than homotypic SARS-CoV-2 Beta RBD-nanoparticles and increased potencies against some SARS-CoV-2 variants than mosaic-7COM. However, mosaic-7COM elicited more potent responses against zoonotic sarbecoviruses and highly mutated Omicrons. These results support using mosaic-7COM to protect against highly mutated SARS-CoV-2 variants and zoonotic sarbecoviruses with spillover potential.

immunology↗

bioRxiv2024

Mosaic sarbecovirus vaccination elicits cross-reactive responses in pre-immunized animals

Immunization with mosaic-8b [60-mer nanoparticles presenting 8 SARS-like betacoronavirus (sarbecovirus) receptor-binding domains (RBDs)] elicits more broadly cross-reactive antibodies than homotypic SARS-CoV-2 RBD-only nanoparticles and protects against sarbecoviruses. To investigate original antigenic sin (OAS) effects on mosaic-8b efficacy, we evaluated effects of prior COVID-19 vaccinations in non-human primates and mice on anti-sarbecovirus responses elicited by mosaic-8b, admix-8b (8 homotypics), or homotypic SARS-CoV-2 immunizations, finding greatest cross-reactivity for mosaic-8b. As demonstrated by molecular fate-mapping in which antibodies from specific cohorts of B cells are differentially detected, B cells primed by WA1 spike mRNA-LNP dominated antibody responses after RBD-nanoparticle boosting. While mosaic-8b- and homotypic-nanoparticles boosted cross-reactive antibodies, de novo antibodies were predominantly induced by mosaic-8b, and these were specific for variant RBDs with increased identity to RBDs on mosaic-8b. These results inform OAS mechanisms and support using mosaic-8b to protect COVID-19 vaccinated/infected humans against as-yet-unknown SARS-CoV-2 variants and animal sarbecoviruses with human spillover potential.

immunology↗

bioRxiv2023

Multiviral Quartet Nanocages Elicit Broad Anti-Coronavirus Responses for Proactive Vaccinology

Defending against future pandemics may require vaccine platforms that protect across a range of related pathogens. The presentation of multiple receptor-binding domains (RBDs) from evolutionarily-related viruses on a nanoparticle scaffold elicits a strong antibody response to conserved regions. Here we produce quartets of tandemly-linked RBDs from SARS-like betacoronaviruses coupled to the mi3 nanocage through a SpyTag/SpyCatcher spontaneous reaction. These Quartet Nanocages induce a high level of neutralizing antibodies against several different coronaviruses, including against viruses not represented on the vaccine. In animals primed with SARS-CoV-2 Spike, boost immunizations with Quartet Nanocages increased the strength and breadth of an otherwise narrow immune response. Quartet Nanocages are a strategy with potential to confer heterotypic protection against emergent zoonotic coronavirus pathogens and facilitate proactive pandemic protection. One Sentence SummaryA vaccine candidate with polyprotein antigens displayed on nanocages induces neutralizing antibodies to multiple SARS-like coronaviruses.

immunology↗

bioRxiv2022

ESCRT recruitment to mRNA-encoded SARS-CoV-2 spike induces virus-like particles and enhanced antibody responses

Prime-boost regimens for COVID-19 vaccines elicit poor antibody responses against Omicron-based variants and employ frequent boosters to maintain antibody levels. We present a natural infection-mimicking technology that combines features of mRNA- and protein nanoparticle-based vaccines through encoding self-assembling enveloped virus-like particles (eVLPs). eVLP assembly is achieved by inserting an ESCRT- and ALIX-binding region (EABR) into the SARS-CoV-2 spike cytoplasmic tail, which recruits ESCRT proteins to induce eVLP budding from cells. Purified spike-EABR eVLPs presented densely-arrayed spikes and elicited potent antibody responses in mice. Two immunizations with mRNA-LNP encoding spike-EABR elicited potent CD8+ T-cell responses and superior neutralizing antibody responses against original and variant SARS-CoV-2 compared to conventional spike-encoding mRNA-LNP and purified spike-EABR eVLPs, improving neutralizing titers >10-fold against Omicron-based variants for three months post-boost. Thus, EABR technology enhances potency and breadth of vaccine-induced responses through antigen presentation on cell surfaces and eVLPs, enabling longer-lasting protection against SARS-CoV-2 and other viruses.

immunology↗

bioRxiv2022

Neutralizing monoclonal antibodies elicited by mosaic RBD nanoparticles bind conserved sarbecovirus epitopes

Protection from SARS-related coronaviruses with spillover potential and SARS-CoV-2 variants could prevent and/or end pandemics. We show that mice immunized with nanoparticles co-displaying spike receptor-binding domains (RBDs) from eight sarbecoviruses (mosaic-8 RBD-nanoparticles) efficiently elicit cross-reactive anti-sarbecovirus antibodies against conserved class 1/4 and class 3 RBD epitopes. Monoclonal antibodies (mAbs) identified from initial screening of <10,000 single B-cells secreting IgGs binding two or more sarbecovirus RBDs showed cross-reactive binding and neutralization of SARS-CoV-2 variants and animal sarbecoviruses. Single-particle cryo-EM structures of antibody-spike complexes, including a Fab-Omicron complex, mapped neutralizing mAbs to conserved class 1/4 RBD epitopes and revealed neutralization mechanisms, potentials for intra-spike trimer crosslinking by single IgGs, and induced changes in trimer upon Fab binding. In addition, we identified a mAb resembling Bebtelovimab, an EUA-approved human class 3 anti-RBD mAb. These results support using mosaic RBD-nanoparticles to identify therapeutic pan-sarbecovirus and pan-variant mAbs and to elicit them by vaccination.

immunology↗

bioRxiv2022

Mosaic RBD nanoparticles protect against multiple sarbecovirus challenges in animal models

To combat future SARS-CoV-2 variants and spillovers of SARS-like betacoronaviruses (sarbecoviruses) threatening global health, we designed mosaic nanoparticles presenting randomly-arranged sarbecovirus spike receptor-binding domains (RBDs) to elicit antibodies against conserved/relatively-occluded, rather than variable/immunodominant/exposed, epitopes. We compared immune responses elicited by mosaic-8 (SARS-CoV-2 and seven animal sarbecoviruses) and homotypic (only SARS-CoV-2) RBD-nanoparticles in mice and macaques, observing stronger responses elicited by mosaic-8 to mismatched (not on nanoparticles) strains including SARS-CoV and animal sarbecoviruses. Mosaic-8 immunization showed equivalent neutralization of SARS-CoV-2 variants including Omicron and protected from SARS-CoV-2 and SARS-CoV challenges, whereas homotypic SARS-CoV-2 immunization protected only from SARS-CoV-2 challenge. Epitope mapping demonstrated increased targeting of conserved epitopes after mosaic-8 immunization. Together, these results suggest mosaic-8 RBD-nanoparticles could protect against SARS-CoV-2 variants and future sarbecovirus spillovers.

microbiology↗

bioRxiv2021

Broad cross-reactivity across sarbecoviruses exhibited by a subset of COVID-19 donor-derived neutralizing antibodies

Many anti-SARS-CoV-2 neutralizing antibodies target the ACE2-binding site on viral spike receptor-binding domains (RBDs). The most potent antibodies recognize exposed variable epitopes, often rendering them ineffective against other sarbecoviruses and SARS-CoV-2 variants. Class 4 anti-RBD antibodies against a less-exposed, but more-conserved, cryptic epitope could recognize newly-emergent zoonotic sarbecoviruses and variants, but usually show only weak neutralization potencies. We characterized two class 4 anti-RBD antibodies derived from COVID-19 donors that exhibited broad recognition and potent neutralization of zoonotic coronavirus and SARS-CoV-2 variants. C118-RBD and C022-RBD structures revealed CDRH3 mainchain H-bond interactions that extended an RBD {beta}-sheet, thus reducing sensitivity to RBD sidechain changes, and epitopes that extended from the cryptic epitope to occlude ACE2 binding. A C118-spike trimer structure revealed rotated RBDs to allow cryptic epitope access and the potential for intra-spike crosslinking to increase avidity. These studies facilitate vaccine design and illustrate potential advantages of class 4 RBD-binding antibody therapeutics.

immunology↗

bioRxiv2021

Engaging the complexity of diet and healthy aging in humans

Little is known about how normal variation in dietary patterns in humans affects the aging process, largely because both nutrition and the physiology of aging are highly complex and multidimensional. Here, we apply the nutritional geometry framework to data from 1560 older adults followed over four years to assess how nutrient intake patterns affect the aging process. Aging was quantified via blood biomarkers integrated to measure loss of homeostasis. Additionally, we extend nutritional geometry to 19 micronutrients. Salient results include benefits of intermediate protein and vitamin E intake. Broadly, we show that there are few simple answers of "good" or "bad" nutrients - optimal levels are generally intermediate, but dependent on other nutrients. Simpler linear/univariate analytical approaches are insufficient to capture such associations. We present an interactive tool to explore the results, and our approach presents a roadmap for future studies to explore the full complexity of the nutrition-aging landscape. Impact StatementMultidimensional nutritional analyses reveal how the association between diet and healthy aging is hard to untangle, as most nutrients have non-linear and interactive effects in humans.

bioinformatics↗