Publications by authors named "Takahama S"

Article Synopsis
  • * It finds that the frequency of SIV-Gag-specific follicular CD8 T cells is linked to the amount of SIV-RNA, particularly in treated or naturally controlling macaques, while showing a different behavior in untreated macaques.
  • * The research indicates that the gene expression profile of fCD8 T cells in naturally controlled infections is more favorable compared to those under cART, suggesting that improving these cells may lead to potential curative strategies for HIV/SIV.
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Recent years have shown that secondary ice production (SIP) is ubiquitous, affecting all clouds from polar to tropical regions. SIP is not described well in models and may explain biases in warm mixed-phase cloud ice content and structure. Through modeling constrained by in-situ observations and its synergy with radar we show that SIP in orographic clouds exert a profound impact on the vertical distribution of hydrometeors and precipitation, especially in seeder-feeder cloud configurations.

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Globally, billions of people burn fuels indoors for cooking and heating, which contributes to millions of chronic illnesses and premature deaths annually. Additionally, residential burning contributes significantly to black carbon emissions, which have the highest global warming impacts after carbon dioxide and methane. In this study, we use Fourier transform infrared spectroscopy (FTIR) to analyze fine-particulate emissions collected on Teflon membrane filters from 15 cookstove types and 5 fuel types.

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People living with HIV (PLWH) could be at risk of blunted immune responses to COVID-19 vaccination. We investigated factors associated with neutralizing antibody (NAb) responses against SARS-CoV-2 and variants of concern (VOCs), following two-dose and third booster monovalent COVID-19 mRNA vaccination in Japanese PLWH. NAb titers were assessed in polyclonal IgG fractions by lentiviral-based pseudovirus assays.

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CD8 T cells affect the outcomes of pancreatic ductal adenocarcinoma (PDAC). Using tissue samples at pre-treatment to monitor the immune response is challenging, while blood samples are beneficial in overcoming this limitation. In this study, we measured peripheral antigen-specific CD8 T cell responses against four different tumor-associated antigens (TAAs) in PDAC using flow cytometry and investigated their relationships with clinical features.

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Background: Liver transplant recipients (LTRs) are at a high risk of severe COVID-19 owing to immunosuppression and comorbidities. LTRs are less responsive to mRNA vaccines than healthy donors (HDs) or other immunosuppressed patients. However, the disruption mechanism in humoral and cellular immune memory responses is unclear.

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Despite treatment, hepatitis B surface antigen (HBsAg) persists in patients with chronic hepatitis B (CHB), suggesting the likely presence of the virus in the body. CD8 T cell responses are essential for managing viral replication, but their effect on HBsAg levels remains unclear. We studied the traits of activated CD8 T cells and HBV-specific CD8 T cells in the blood of CHB patients undergoing nucleos(t)ide analog (NUC) therapy.

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Cancer‑associated fibroblasts (CAFs) are implicated in the strong malignancy of pancreatic cancer (PC). Various CAF subtypes have different functions, and their heterogeneity likely influence the malignancy of PC. Meanwhile, it is known that senescent cells can create a tumor‑promoting microenvironment by inducing a senescence‑associated secretory phenotype (SASP).

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Understanding the T-cell responses involved in inhibiting COVID-19 severity is crucial for developing new therapeutic and vaccine strategies. Here, we characterized SARS-CoV-2 spike-specific CD8 T cells in vaccinees longitudinally. The BNT162b2 mRNA vaccine can induce spike-specific CD8 T cells cross-reacting to BA.

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Stimulator of interferon genes (STING) is a cytoplasmic dinucleotide sensor used as an immunomodulatory agent for cancer treatment. The efficacy of the STING ligand (STING-L) against various tumors has been evaluated in mouse models; however, its safety and efficacy in non-human primates have not been reported. We examined the effects of escalating doses of cyclic-di-adenosine monophosphate (c-di-AMP) or cyclic [G (3',5')pA (3',5'p] (3'-3'-cGAMP) administered intramuscularly or intravenously to cynomolgus macaques.

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Small CD4-mimetic compound (CD4mc), which inhibits the interaction between gp120 with CD4, acts as an entry inhibitor and induces structural changes in the HIV-1 envelope glycoprotein trimer (Env) through its insertion within the Phe43 cavity of gp120. We recently developed YIR-821, a novel CD4mc, that has potent antiviral activity and lower toxicity than the prototype NBD-556. To assess the possibility of clinical application of YIR-821, we tested its antiviral activity using a panel of HIV-1 pseudoviruses from different subtypes.

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Efficient delivery of subunit vaccines to dendritic cells (DCs) is necessary to improve vaccine efficacy, because the vaccine antigen alone cannot induce sufficient protective immunity. Here, we identified DC-targeting peptides using a phage display system and demonstrated the potential of these peptides as antigen-delivery carriers to improve subunit vaccine effectiveness in mice. The fusion of antigen proteins and peptides with DC-targeting peptides induced strong antigen-specific IgG responses, even in the absence of adjuvants.

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Article Synopsis
  • Research identifies several cross-protective antibodies that target a wide variety of influenza A virus strains and help eliminate the virus through immune mechanisms like Fcγ receptor (FcγR) activity and neutralizing effects.
  • An original assay was developed to study how purified FI6 IgG interacts with cells presenting hemagglutinin (HA) using flow cytometry, with tests conducted on peripheral blood mononuclear cells from cynomolgus macaques.
  • The study showed that after administering an influenza vaccine, classical monocytes, a specific type of immune cell, predominantly engaged with HA-expressing cells through the FcγR pathway, suggesting this assay could aid in creating a universal influenza
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  • A new AI system, called MSP AI-G, has been developed to assist pathologists in diagnosing gastric biopsies more efficiently and accurately across various medical institutions.
  • This system uses a technique known as multistage semantic segmentation, which mimics how pathologists view tissue samples under a microscope, leading to a higher diagnostic accuracy of 91.0% compared to 89.8% for traditional AI methods.
  • MSP AI-G has demonstrated strong performance in diverse clinical settings, and it reduces the need for additional reviews by pathologists when initial diagnoses differ from AI predictions, streamlining the diagnostic process.
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The quality and size of liver grafts are critical factors that influence living-donor liver transplantation (LDLT) function and safety. However, the biomarkers used for predicting graft quality are lacking. In this study, we sought to identify unique graft quality markers, aside from donor age, by using the livers of non-human primates.

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Background: Human immunodeficiency virus (HIV) and hepatitis C virus (HCV) coinfection through unheated blood product for hemophilia caused in early 1980s has been significantly serious problem in Japan. After the development of HIV treatment in 1990s, HCV-related hepatocellular carcinoma (HCC) has been one of the most significant problem in these population. Treatment choices for HCC might be limited in hemophilia patients because of their bleeding tendency.

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Background: Recent data suggest the importance of non-neutralizing antibodies (nnAbs) in the development of vaccines against HIV-1 because two types of nnAbs that recognize the coreceptor binding site (CoRBS) and the C1C2 region mediate antibody-dependent cellular-cytotoxicity (ADCC) against HIV-1-infected cells. However, many studies have been conducted with nnAbs obtained from subtype B-infected individuals, with few studies in patients with non-subtype B infections.

Results: We isolated a monoclonal antibody 1E5 from a CRF02_AG-infected individual and constructed two forms of antibody with constant regions of IgG1 or IgG3.

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This 31-parameter panel was developed for simultaneously measuring multiple immune cell populations including T cells, B cells, natural killer cells, dendritic cells, monocytes, and hematopoietic progenitor cells in human peripheral blood mononuclear cells. This panel enables the capture of individual immune dynamics and assessments of single-cell changes in the immune system that are associated with aging and diseases. This panel includes markers to separate the differentiation status of each cell population and might be applicable to studies of infectious and autoimmune diseases, as patient samples are usually limited in volume and require an analysis system that provides a relatively large amount of information.

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Isolation of antigen (Ag)-specific T cells is an important step in the investigation of T-cell immunity. Activation-induced markers (AIMs), such as CD154/tumor necrosis factor (TNF)/CD107A/CD134/CD137 enable the sorting of Ag-specific T cells without using human leukocyte antigen (HLA)-multimers. However, optimal conditions suitable for simultaneous detection of both Ag-specific CD4 and CD8 T cells have not been investigated.

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Article Synopsis
  • Neurospora crassa is a type of fungus that can live and grow for over 2 years, but a mutation in the nd gene makes it only live for about 20 days.
  • Scientists found a mutation in the msh1 gene, which is important for fixing DNA and helps the fungus grow properly.
  • When they removed the msh1 gene, the fungus had serious growth problems and damage to its mitochondrial DNA, suggesting that the msh1 gene helps keep the fungus healthy and not aging too fast.
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Toll-like receptors (TLRs) were first identified as molecular sensors that transduce signals from specific structural patterns derived from pathogens; their underlying molecular mechanisms of recognition and signal transduction are well-understood. To date, more than 20 pattern-recognition receptors (PRRs) have been reported in humans, some of which are membrane-bound, similar to TLRs, whereas others are cytosolic, including retinoic acid-inducible gene-I (RIG-I)-like receptors (RLRs), nucleotide-binding oligomerization domain (NOD)-like receptors (NLRs), and stimulator of interferon genes (STING). Clinically, PRR ligands have been developed as vaccine adjuvants to activate innate immunity and enhance subsequent antigen-specific immune responses.

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Water activity and related thermodynamic properties are calculated for several aqueous solutions using equilibrium molecular dynamics in conjunction with the recent extension of the Kirkwood-Buff (KB) theory for closed systems. The general applicability of this method is evaluated on aqueous mixtures of ethanol, glyoxal, malonic acid, and NaCl, which represent different types of condensed-phase interactions. Solution microstructures are analyzed using KB integrals and cluster analysis to identify molecular associations due to hydrophobic interactions, hydrate formation, hydrogen bonding, or electrostatic forces affecting solution nonideality in the different systems.

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Cell-to-cell spread of HIV permits ongoing viral replication in the presence of antiretroviral therapy and is suggested to be a major contributor to sexual transmission by mucosal routes. Fusion inhibitors that prevent viral entry have been developed, but their clinical applications have been limited by weak antiviral activity, short half-life, and the low genetic barrier to development of resistance. We examined the inhibitory activities of a series of single-chain variable fragments (scFvs) targeting the V3 and CD4i epitopes against both cell-free and cell-to-cell HIV infection.

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