Biology subjects

Tsuji, M.

Publications and source records attributed to Tsuji, M..

10 recordsLinked to original sources

bioRxiv2026

A novel model demonstrating that human immune cells promote multiorgan SARS-CoV-2 dissemination and human T cells limit anti-viral innate immunity

Despite extensive studies, many questions remain regarding the pathology and mechanisms behind Coronavirus disease 2019 (COVID-19), and particularly on post-acute sequelae of COVID-19 (PASC). Because existing mouse models cannot recapitulate human immune responses, we developed a human immune system (HIS) mouse model with physiologic expression of hACE2. After intranasal infection, persistent viral RNA was observed in multiple organs for 8 weeks, despite the generation of human SARS-CoV-2-specific T cell responses. Human immune cells increased viral infection in the lung and non-pulmonary tissues. COVID-19-related pathology was recapitulated in the lungs, with fibrosis peaking at 14 days post-infection. Immune activation was detected in the lungs, hearts, intestines and brains of acutely infected mice and persisted at 8 weeks in the heart and lungs. The presence of human T cells correlated with attenuated innate antiviral transcriptional signatures in the lung, where a persisting cytotoxic mature CD4+ T cell population with JAK-STAT activation was enriched in infected mice. Thus, human T cells mount an antigen-specific but ultimately dysfunctional response, while paradoxically suppressing the innate interferon response, permitting chronic interferon activation and long-term viral persistence, recapitulating several immunologic and histopathologic features associated with PASC. This model will uniquely facilitate understanding of virus-human immune dynamics and therapeutic approaches to PASC.

immunology↗

bioRxiv2025

Dopaminergic Neurons in the Brain Orchestrates Cardiac and Behavioral Threat Responses

Heartbeat and behavior are tightly coordinated during defensive states, yet the neuronal mechanisms linking threat processing to cardiac modulation--and the potential contribution of cardiac dynamics to behavioral output--remain poorly understood. Here we show in Drosophila that mechanical threat triggers locomotion together with cardiac deceleration. We identify two pairs of dopaminergic neurons, termed DA-WED neurons, that mediate this cardiac response: silencing these neurons markedly attenuates threat-induced cardiac deceleration, whereas optogenetic activation induces cardiac deceleration in the absence of threat. Calcium imaging further shows that DA-WED neurons are activated by mechanical threat. Linking cardiac dynamics to behavior, direct optogenetic manipulation of cardiomyocytes that quantitatively reproduces threat-evoked cardiac deceleration is accompanied by increased locomotion. Together, these results identify a dopaminergic descending pathway that links threat processing to cardiac modulation and suggest that cardiac dynamics may contribute to shaping defensive behavior.

neuroscience↗

bioRxiv2025

Repeated stress persistently suppressesthe central node in the courtship circuitry in Drosophila

Stress caused by external stressors, such as painful stimulation, can elicit a drastic set of behavioral responses. Such stress responses normally decay soon after the stressor disappears, but can become persistent when the stressor becomes longer and/or repeated. The neuronal mechanism underlying the persistence of stress responses, however, remains elusive. Here, we discovered that repeated electric shocks persistently suppress male Drosophilas courtship behavior. We comprehensively evaluated the physiological changes in the genetically defined courtship circuitry, and found that a courtship-triggering node of the circuitry, called P1 neurons, is preferentially and persistently suppressed following electric shocks. Our data uncovers in a comprehensively defined courtship circuitry that repeated stress persistently suppresses a critical node of the circuitry in a targeted fashion to alter behavior.

neuroscience↗

bioRxiv2025

Neuropeptidergic circuit modulation of developmental sleep in Drosophila

Sleep-wakefulness regulation dynamically evolves along development in a wide range of organisms. While the mechanism regulating sleep in adults are relatively well understood, little is known about its counterpart in early developmental stages. Here we report a neuropeptidergic circuitry that modulates sleep in developing Drosophila larvae. Through an unbiased screen, we identified the neuropeptide Hugin and its receptor PK2-R1 as critical regulators of larval sleep. Our genetic and behavioral data suggest that HugPC neurons secrete Hugin peptides to activate Insulin-producing cells (IPCs), which expresses a Hugin receptor PK2-R1. IPCs, in turn, release insulin-like peptides (Dilps) to regulate sleep. We further show that the Hugin/PK2-R1 axis is dispensable for adult sleep. Our findings thus reveal the neuromodulatry circuit that regulates developmental sleep in larvae, and highlight differential impacts of the same modulatory axis on early-life sleep and adult sleep.

neuroscience↗

bioRxiv2025

Distinct CD8+ T-cell types Associated with COVID-19 Severity in Unvaccinated HLA-A2+ Patients

Although emerging data have revealed the critical role of memory CD8+ T cells in preventing and controlling SARS-CoV-2 infection, virus-specific CD8+ T-cell responses against SARS-CoV-2 and its memory and innate-like subsets in unvaccinated COVID-19 patients with various disease manifestations in an HLA-restricted fashion remain to be understood. Here, we show the strong association of protective cellular immunity with mild COVID-19 and unique cell types against SARS-CoV-2 virus in an HLA-A2 restricted manner. ELISpot assays reveal that SARS-CoV-2-specific CD8+ T-cell responses in mild COVID-19 patients are significantly higher than in severe patients, whereas neutralizing antibody responses against SARS-CoV-2 virus significantly correlate with disease severity. Single-cell analyses of HLA-A2-restricted CD8+ T cells, which recognize highly conserved immunodominant SARS-CoV-2-specific epitopes, demonstrate divergent profiles in unvaccinated patients with mild versus severe disease. CD8+ T-cell types including cytotoxic KLRB1+ CD8 cells with innate-like T-cell signatures, IFNGhiID3hi memory cells and IL7R+ proliferative stem cell-like memory cells are preferentially observed in mild COVID-19, whereas distinct terminally-differentiated T-cell subsets are predominantly detected in severe COVID-19: highly activated FASLhi T-cell subsets and early-terminated or dysfunctional IL4R+ GATA3+ stem cell-like memory T-cell subset. In conclusion, our findings suggest that unique and contrasting SARS-CoV-2-specific CD8+ T-cell profiles may dictate COVID-19 severity. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=143 SRC="FIGDIR/small/632164v1_ufig1.gif" ALT="Figure 1"> View larger version (25K): org.highwire.dtl.DTLVardef@154796corg.highwire.dtl.DTLVardef@efca24org.highwire.dtl.DTLVardef@c01b9corg.highwire.dtl.DTLVardef@54ad83_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOGraphical abstract.C_FLOATNO SARS-CoV-2 epitope-specific CD8+ T-cell subtypes associated with mild or severe COVID-19 patients. Potent memory CD8+ T-cell subtypes with gene signature in mild COVID-19 patients (upper) and dysfunctional CD8+ T-cell subtypes with gene signature in severe COVID-19 patients (lower). C_FIG

immunology↗

bioRxiv2023

STING/RANTES Pathway in Airway Epithelium Stimulates Sensitization to Der p1 in an Asthma Model

BackgroundAsthma development can be attributed to various factors, including viral infections. Several pathogen including viruses activate stimulators of interferon genes (STING), and a small amount of STING agonist functions as adjuvants for sensitization to house dust mite (HDM); however, the associated mechanism is unclear. We investigated the role of STING during sensitization to HDM in airway epithelial cells. MethodsAirway epithelial cell STING expression was analyzed using the GEO database. We delivered cyclic-GMP-AMP (cGAMP), a STING agonist to mice intranasally, and sorted epithelial cells and performed RNA-seq. Human airway epithelial cells (HBEpCs) were stimulated using cGAMP in vitro. Next, we sensitized mice with cGAMP and HDM, Der p1 on Day 1, and challenged with HDM on Day 7, and on Day 8, analyzed cytokine/chemokine levels, bronchoalveolar lavage cell fraction, histology, and the number of group 2 innate lymphoid cells (ILC2s) and dendritic cells (DCs). Furthermore, we evaluated the effect of RANTES/CCL5 alone on sensitizing to HDM. ResultsRelative to other pattern recognition receptors, TMEM173, encoding STING, was highly expressed in HBEpCs, and RANTES expression was remarkably upregulated in cGAMP-treated mice. RANTES, not IL-33 or TSLP, was also activated by cGAMP in HBEpCs, especially in the presence of H2O2. Type 2 cytokine/chemokine, eosinophil, and goblet cell metaplasia increased with ILC2 and cDC2 accumulation in cGAMP-adjuvanted HDM-sensitized mice. RANTES alone functioned as an adjuvant for induction of type 2 inflammation in mice. ConclusionSTING was highly expressed in airway epithelial cells. STING/RANTES axis may be a crucial pathway for stimulating asthma sensitization.

immunology↗

bioRxiv2023

A pancreatic cancer mouse model with human immunity

Pancreatic ductal adenocarcinoma (PDAC) is characterized by a tumor immune microenvironment (TIME) that promotes resistance to immunotherapy. A preclinical model system that facilitates studies of the TIME and its impact on the responsiveness of human PDAC to immunotherapies remains an unmet need. We report a novel mouse model, which develops metastatic human PDAC that becomes infiltrated by human immune cells recapitulating the TIME of human PDAC. The model may serve as a versatile platform to study the nature of human PDAC TIME and its response to various treatments.

cancer biology↗

bioRxiv2021

Isolation and comparative analysis of antibodies that broadly neutralize sarbecoviruses

The devastation caused by SARS-CoV-2 has made clear the importance of pandemic preparedness. To address future zoonotic outbreaks due to related viruses in the sarbecovirus subgenus, we identified a human monoclonal antibody, 10-40, that neutralized or bound all sarbecoviruses tested in vitro and protected against SARS-CoV-2 and SARS-CoV in vivo. Comparative studies with other receptor-binding domain (RBD)-directed antibodies showed 10-40 to have the greatest breadth against sarbecoviruses and thus its promise as an agent for pandemic preparedness. Moreover, structural analyses on 10-40 and similar antibodies not only defined an epitope cluster in the inner face of the RBD that is well conserved among sarbecoviruses, but also uncovered a new antibody class with a common CDRH3 motif. Our analyses also suggested that elicitation of this class of antibodies may not be overly difficult, an observation that bodes well for the development of a pan-sarbecovirus vaccine. One sentence summaryA monoclonal antibody that neutralizes or binds all sarbecoviruses tested and represents a reproducible antibody class.

microbiology↗

bioRxiv2021

The inhibitory effects of toothpaste and mouthwash ingredients on the interaction between the SARS-CoV-2 spike protein and ACE2, and the protease activity of TMPRSS2, in vitro

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) enters host cells when the viral spike protein is cleaved by transmembrane protease serine 2 (TMPRSS2) after binding to the host angiotensin-converting enzyme 2 (ACE2). Since ACE2 and TMPRSS2 are expressed in the mucosa of the tongue and gingiva, the oral cavity seems like it is an entry point for SARS-CoV-2. Daily oral care using mouthwash seems to play an important role in preventing SARS-CoV-2 infection. However, the relationship between daily oral care and the mechanisms of virus entry into host cells is unclear. In this study, we evaluated the inhibitory effects of ingredients that are generally contained in toothpaste and mouthwash on the interaction between the spike protein and ACE2 and on the serine protease activity of TMPRSS2 using an enzyme-linked immunosorbent assay and in vitro enzyme assay, respectively. Both assays detected inhibitory effects of sodium tetradecene sulfonate, sodium N-lauroyl-N-methyltaurate, sodium N-lauroylsarcosinate, sodium dodecyl sulfate, and copper gluconate. Molecular docking simulations suggested that these ingredients could bind to the inhibitor-binding site of ACE2. In addition, tranexamic acid and 6-aminohexanoic acid, which act as serine protease inhibitors, exerted inhibitory effects on TMPRSS2 protease activity. Further experimental and clinical studies are needed to further elucidate these mechanisms. Our findings support the possibility that toothpaste and mouthwash contain ingredients that inhibit SARS-CoV-2 infection.

molecular biology↗

bioRxiv2020

Virus-Like Particle Based-Vaccines Elicit Neutralizing Antibodies against the HIV-1 Fusion Peptide

Broadly neutralizing antibodies (bnAbs) isolated from HIV-infected individuals delineate vulnerable sites on the HIV envelope glycoprotein that are potential vaccine targets. A linear epitope at the N-terminal region of the HIV-1 fusion peptide (FP8) is the primary target of VRC34.01, a bnAb that neutralizes ~50% of primary HIV isolates. FP8 has attracted attention as a potential HIV vaccine target because it is a simple linear epitope. Here, we used platform technologies based on RNA bacteriophage virus-like particles (VLPs) to develop multivalent vaccines targeting the FP8 epitope. We produced recombinant MS2 VLPs displaying the FP8 peptide and we chemically conjugated synthetic FP8 peptides to Q{beta} VLPs. Both recombinant and conjugated FP8-VLPs induced high titers of FP8-specific antibodies in mice. A heterologous prime-boost-boost regimen employing the two FP8-VLP vaccines and native envelope trimer was the most effective approach for eliciting HIV-1 neutralizing antibodies. Given the potent immunogenicity of VLP-based vaccines, this vaccination strategy - inspired by bnAb-guided epitope mapping, VLP bioengineering, and optimal prime-boost immunization strategies - may be an effective strategy for eliciting bnAb responses against HIV.

immunology↗