Biology subjects

Rho, S.

Publications and source records attributed to Rho, S..

8 recordsLinked to original sources

bioRxiv2026

A mosaic RBD-nanoparticle pan-sarbecovirus vaccine elicits nanobodies that target highly conserved epitopes

SARS-CoV-2, the virus that causes COVID-19, continually mutates, producing new variants of concern (VOCs). Substitutions in the SARS-CoV-2 spike protein receptor-binding domain (RBD) have resulted in reduced efficacies of vaccines and therapeutic monoclonal antibodies. Indeed, since the emergence of Omicron and earlier VOCs, most previously approved anti-RBD therapeutic monoclonal antibodies are no longer authorized as therapeutics. To address VOC substitutions effects on therapeutic antibody efficacy, we sought to identify single-domain nanobodies (VHHs) targeting RBD regions (class 4, class 1/4, portions of class 3 and class 5 RBD epitopes) that are more conserved across VOCs, reasoning that the smaller size of camelid nanobodies compared with conventional two-domain antibody combining sites would facilitate access to occluded RBD epitopes. We used a Beacon optofluidic platform to isolate and characterize single memory B cells from a llama immunized with a mosaic RBD-nanoparticle immunogen that elicits broad antibody responses across sarbecoviruses. Using multiplex binding assays, we identified nanobodies that bind to spike RBDs from diverse sarbecovirus strains. Competition ELISAs and crystal structures of VHH-RBD complexes showed that isolated nanobodies recognize broadly conserved epitopes, including those on the RBD that are inaccessible to analogous conventional two-domain antibodies. Promising VHH-Fcs neutralized SARS-CoV-2 variants of concern and zoonotic sarbecoviruses, demonstrating potential therapeutic utility for current and future outbreaks.

immunology↗

bioRxiv2026

Distributed resonant coupling enables high efficiency power transfer to mm-scale bioelectronics

Miniaturized implantable bioelectronics offer breakthrough potential in disease treatment, biomarker monitoring, and physiological sensing. However, wireless power transfer (WPT) remains a central limitation for millimeter-scale devices, as scaling down the receiver size rapidly decreases coupling efficiency due to tissue attenuation, low quality-factors, reduced mutual inductance, and limited tolerance to spatial and angular displacement. Here, we introduce distributed resonant coupling (DRC), a 3-coil WPT paradigm which enables the receiver (Rx) to actively participate in a strongly coupled resonance, transforming the Rx from a passive energy harvester into an active participant in a strongly coupled regime. By co-designing transmitters (Tx), resonators (Rs), and mm-scale receiver coils (Rx) as fully coupled systems, DRC exhibits simulated maximum power levels of 66%, measured received power transfer efficiencies of [~]56%, and end-to-end DC power transfer efficiencies of 42%, delivering >420 mW to loads at 1 W of transmitted power while maintaining robust performance across a range of practically relevant orientations and tissue media. Systematic theoretical and experimental efforts establish core design rules for DRC systems enabling operation without specialized tuning integrated circuits or components. To illustrate the capabilities of DRC in practical applications in vivo, we demonstrate three technologies that capture a broad application space in bioelectronics: implant localization, rapid wireless battery charging, and ultraminiaturized drug delivery devices compatible with particulate drug formulations. Taken together, these results suggest operational capabilities across a wide range of angular tolerances (up to 60{degrees}), tissue depths and dielectric and scattering media.

bioengineering↗

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

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↗

bioRxiv2025

An ultra-long heavy chain bovine antibody neutralizes SARS-CoV-2 and reacts broadly with sarbecoviruses.

The ongoing threat of new SARS-CoV-2 variants and other sarbecoviruses has driven efforts to develop broadly neutralizing monoclonal antibodies (mAbs). This study used immunized cattle, known for producing antibodies with ultra-long CDRH3 domains, to generate 33 mAbs, ten of which had ultra-long CDRH3s (>50 amino acids). Of these, mAbs P7 and 99, demonstrated broad and potent neutralization. Notably, mAb P7 neutralized all tested variants, including SARS-CoV-1, with IC50 values between 0.05 and 9.2 {micro}g/mL, and showed cross-reactivity with RBDs from various sarbecoviruses. Structural analysis revealed that mAb 99 binds the spike proteins RBD at the ACE2 binding site. Although the exact binding of P7 wasnt resolved, evidence suggests it targets a hidden epitope, promoting spike trimer dissociation via its extended CDRH3. In Syrian hamsters, both mAbs significantly reduced lung viral loads. These results support the potential of bovine-derived mAbs, particularly those with ultra-long CDRH3s, for future antiviral therapies.

immunology↗

bioRxiv2024

Intestinal Dysbiosis Alters Acute Seizure Burden and Antiseizure Medicine Activity in the Theiler's Virus Model of Encephalitis

ObjectiveBrain infection with Theilers virus (TMEV) in C57BL/6J mice produces an etiologically relevant model of acquired seizures. Dietary changes can modify acute seizure presentation following TMEV brain infection and influence intestinal microbiome diversity and composition. Intestinal dysbiosis may thus similarly affect seizure burden and antiseizure medicine (ASM) activity in this model, independent of pharmacokinetic effects. We thus sought to define the influence of antibiotic (ABX)-induced gut dysbiosis on acute seizure presentation, anticonvulsant activity of carbamazepine (CBZ), and CBZ pharmacokinetics with TMEV infection. MethodsMale C57BL/6J mice (4-5 weeks) received oral (p.o.) ABX or saline (SAL) once daily beginning on arrival through Day 7 post-TMEV infection (p.i.). Mice were infected with TMEV or PBS on Day 0. Mice received intraperitoneal (i.p.; 20 mg/kg) CBZ or vehicle (VEH) twice daily Days 3-7 p.i. and were assessed for handling-induced seizures 30 min after treatment. Plasma was collected on Day 7 p.i. at 15 and 60 min post-CBZ administration for bioanalysis. ResultsTMEV infection induced acute seizures, but ABX-induced gut dysbiosis altered seizure presentation. There were 75% SAL-VEH, 35% SAL-CBZ, 35% ABX-VEH, and 72% ABX- CBZ mice with seizures during the 7-day monitoring period. There was a significant pretreatment x ASM interaction (p=0.0001), with differences in seizure burden in SAL- versus ABX-pretreated mice (p=0.004). CBZ significantly increased latency to seizure presentation; an effect absent in ABX-CBZ mice. Plasma CBZ concentrations did not differ between SAL and ABX pretreatment groups, suggesting that ABX did not influence CBZ pharmacokinetics. SignificanceABX-induced gut dysbiosis markedly altered acute disease trajectory with TMEV- induced encephalitis, reflecting a novel contribution of the gut microbiome to seizure presentation. ABX-induced gut dysbiosis also significantly changed acute seizure control by CBZ, but did not influence plasma CBZ concentrations. The gut-brain axis is thus an under- recognized contributor to TMEV infection-induced seizures, ASM activity, and disease burden. Key PointsO_LITheilers virus infection in mice models encephalitis that exhibits differential disease trajectory with gut microbiome modulation. C_LIO_LIExperimentally evoked gut dysbiosis, i.e. a disrupted gut microbiome, dramatically shifts the anticonvulsant activity of carbamazepine. C_LIO_LIThere is no concomitant shift in circulating carbamazepine concentrations in TMEV- infected mice with and without a dysbiotic microbiome. C_LIO_LIThe gut microbiome is an under-recognized driver of seizure risk and antiseizure medicine activity in the Theilers virus mouse model. C_LI

neuroscience↗

bioRxiv2021

Measurements of acoustic radiation force of ultrahigh frequency ultrasonic transducers using model-based approach

Even though ultrahigh frequency ultrasonic transducers over 60 MHz have been used for single cell level manipulation such as intracellular delivery, acoustic tweezers, and stimulation to investigate cell phenotype and cell mechanics, no techniques have been available to measure actual acoustic radiation force (ARF) applied to target cells. Therefore, we have developed an approach to measure ARF of ultrahigh frequency ultrasonic transducers using theoretical model of the dynamics of a solid sphere in a gelatin phantom. To estimate ARF at the focus of 130 MHz transducer, we matched measured maximum displacements of a solid sphere with theoretical calculations. We selected appropriate ranges of input voltages and pulse durations for single cell applications and estimated ARF were in the range of tens of pN to nN. FRET live cell imaging was demonstrated to visualize calcium transport between cells after a target single cell was stimulated by the developed ultrasonic transducer.

bioengineering↗

bioRxiv2020

Nicotinamide provides neuroprotection in glaucoma by protecting against mitochondrial and metabolic dysfunction

Nicotinamide adenine dinucleotide (NAD) is a REDOX cofactor and metabolite essential for neuronal survival. Glaucoma is a common neurodegenerative disease in which neuronal levels of NAD decline. Repleting NAD via dietary supplementation of nicotinamide (a precursor to NAD) is effective in preventing retinal ganglion cell neurodegeneration in mouse models. Supporting this, short-term oral nicotinamide treatment in human glaucoma patients provides a recovery of retinal ganglion cell function implying a protection of visual function. Despite this, the mechanism of neuroprotection and full effects of nicotinamide on retinal ganglion cells is unclear. Glaucoma is a complex neurodegenerative disease in which a mix of healthy, stressed, and degenerating retinal ganglion cells co-exist, and in which retinal ganglion cells display compartmentalized degeneration across their visual trajectory. Therefore, we assess the effects of nicotinamide on retinal ganglion cells in normal physiological conditions and across a range of glaucoma relevant insults. We confirm neuroprotection afforded by nicotinamide in rodent models which represent isolated ocular hypertensive, axon degenerative, and mitochondrial degenerative insults. We define a small molecular weight metabolome for the retina, optic nerve, and superior colliculus which demonstrates that ocular hypertension induces widespread metabolic disruption that can be prevented by nicotinamide. Nicotinamide provides these neuroprotective effects by increasing oxidative phosphorylation, buffering and preventing metabolic stress, and increasing mitochondrial size and motility whilst simultaneously dampening action potential firing frequency. These data support continued determination of the utility of long-term NAM treatment as a neuroprotective therapy for human glaucoma. One Sentence SummaryThe NAD precursor nicotinamide has a potent neuroprotective effect in the retina and optic nerve, targeting neuronal function, metabolism, and mitochondrial function.

neuroscience↗