Publications by authors named "Kazuhisa Yoshimura"

We identified a 5-fluoro-benzothiazole-containing small molecule, TKB272, through fluorine-scanning of the benzothiazole moiety, which more potently inhibits the enzymatic activity of SARS-CoV-2's main protease (M) and more effectively blocks the infectivity and replication of all SARS-CoV-2 strains examined including Omicron variants such as SARS-CoV-2 and SARS-CoV-2 than two M inhibitors: nirmatrelvir and ensitrelvir. Notably, the administration of ritonavir-boosted nirmatrelvir and ensitrelvir causes drug-drug interactions warranting cautions due to their CYP3A4 inhibition, thereby limiting their clinical utility. When orally administered, TKB272 blocked SARS-CoV-2 replication without ritonavir in B6.

View Article and Find Full Text PDF

Background: Emergence of SARS-CoV-2 variants that escape neutralising antibodies hampers the development of vaccines and therapeutic antibodies against SARS-CoV-2. IGHV3-53/3-66-derived public antibodies, which are generally specific to the prototype virus and are frequently induced in infected or vaccinated individuals, show minimal affinity maturation and high potency against prototype SARS-CoV-2.

Methods: Monoclonal antibodies isolated from a Delta breakthrough infection case were analysed for cross-neutralising activities against SARS-CoV-2 variants.

View Article and Find Full Text PDF

The introduction of combined antiretroviral therapy (cART) has greatly improved the quality of life of human immunodeficiency virus type 1 (HIV-1)-infected individuals. Nonetheless, the ever-present desire to seek out a full remedy for HIV-1 infections makes the discovery of novel antiviral medication compelling. Owing to this, a new late-stage inhibitor, Lenacapavir/Sunlenca, an HIV multi-phase suppressor, was clinically authorized in 2022.

View Article and Find Full Text PDF

Background: Highly transmissible viruses including SARS-CoV-2 frequently accumulate novel mutations that are detected via high-throughput sequencing. However, there is a need to develop an alternative rapid and non-expensive approach. Here we developed a novel multiplex DNA detection method Intelli-OVI for analysing existing and novel mutations of SARS-CoV-2.

View Article and Find Full Text PDF

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has acquired multiple mutations since its emergence. Analyses of the SARS-CoV-2 genomes from infected patients exhibit a bias toward C-to-U mutations, which are suggested to be caused by the apolipoprotein B mRNA editing enzyme polypeptide-like 3 (APOBEC3, A3) cytosine deaminase proteins. However, the role of A3 enzymes in SARS-CoV-2 replication remains unclear.

View Article and Find Full Text PDF
Article Synopsis
  • A new variant of SARS-CoV-2, called EG.5.1, is spreading rapidly and has been studied using various scientific methods to understand its features.
  • Key mutations in EG.5.1, specifically S:F456L and ORF9b:I5T, enhance its viral fitness compared to other variants like XBB.1.5.
  • Structural differences were found in the spike proteins of EG.5.1 versus XBB.1.5, and the research helps us understand the evolution of emerging viruses that can affect human health.
View Article and Find Full Text PDF
Article Synopsis
  • Researchers isolated a coronavirus called BANAL-20-236 (B236) from Malayan horseshoe bats and found it lacks a key site in its spike protein that is present in SARS-CoV-2.
  • * They compared B236's characteristics using human-derived cells and hamster infection experiments, discovering it's less pathogenic and grows slower in respiratory cells compared to SARS-CoV-2, but grows better in intestinal cells.
  • * The study suggests that SC2r-CoVs like B236 may primarily replicate in the intestines rather than the respiratory system, supporting prior findings about its behavior in other models.
View Article and Find Full Text PDF
Article Synopsis
  • * A notable rise in syphilis cases has been observed among women in their 20s, increasing over three times, while the number of pregnant women with the disease also rose at the end of 2022.
  • * While congenital syphilis rates have remained stable due to effective early detection during pregnancy, the rising trend among young women poses a risk for future outbreaks, highlighting the need for targeted public health education and testing strategies.
View Article and Find Full Text PDF

Toward human immunodeficiency virus type-1 (HIV-1) cure, cells latently infected with HIV-1 must be eliminated from people living with HIV-1. We previously developed a protein kinase C (PKC) activator, diacylglycerol (DAG)-lactone derivative , with high HIV-1 latency-reversing activity, based on YSE028 () as a lead compound and found that the activity was correlated with binding affinity for PKC and stability against esterase-mediated hydrolysis. Here, we synthesized new DAG-lactone derivatives not only containing a tertiary ester group or an isoxazole surrogate but also several symmetric alkylidene moieties to improve HIV-1 latency reversing activity.

View Article and Find Full Text PDF
Article Synopsis
  • In late 2023, the SARS-CoV-2 BA.2.86 variant emerged alongside the dominant XBB descendants like EG.5.1, distinguishing itself with over 30 mutations in its spike protein.
  • Modeling showed BA.2.86 has a higher reproduction number compared to EG.5.1, suggesting it spreads more easily.
  • Despite its increased spread, BA.2.86 demonstrated lower pathogenicity and replication capacity in hamsters, indicating it may be less severe, while remaining sensitive to four existing antiviral treatments.
View Article and Find Full Text PDF

Background: Integrase strand transfer inhibitors (INSTIs) are recommended as first-line ART for people living with HIV (PLWH) in most guidelines. The INSTI-resistance-associated mutation E157Q, a highly prevalent (2%-5%) polymorphism of the HIV-1 (human immunodeficiency virus type 1) integrase gene, has limited data on optimal first-line ART regimens. We assessed the virological outcomes of various first-line ART regimens in PLWH with E157Q in real-world settings.

View Article and Find Full Text PDF
Article Synopsis
  • Most research on SARS-CoV-2 variants has concentrated on mutations in spike proteins that influence how the virus infects and spreads.
  • This study highlights that there are also significant mutations outside of the spike protein that can affect the virus's behavior.
  • Specifically, the study found that certain mutations in the Omicron BA.2 variant, including one in the spike protein and another further down the gene, play crucial roles in defining its characteristics.
View Article and Find Full Text PDF

Objective: There are few valid indicators of oral infection owing to the complexity of pathogenic factors in oral diseases. Salivary markers are very useful for scrutinizing the symptoms of disease. To provide a reliable and useful predictive indicator of infection for opportunistic pathogens in individuals with compromised immune systems, such as those with periodontal diseases and Human Immunodeficiency Virus (HIV), this study examines opportunistic pathogens such as and staphylococci and macrophage colony-stimulating factor (M-CSF) and CA125/MUC16 in saliva.

View Article and Find Full Text PDF

Cells latently infected with human immunodeficiency virus type 1 (HIV-1) prevent people living with HIV-1 from obtaining a cure to the infectious disease. Latency reversing agents (LRAs) such as protein kinase C (PKC) activators and histone deacetylase (HDAC) inhibitors can reactivate cells latently infected with HIV-1. Several trials based on treatment with HDAC inhibitors alone, however, failed to reduce the number of latent HIV-1 reservoirs.

View Article and Find Full Text PDF
Article Synopsis
  • - Late HIV diagnosis in Japan is a significant issue, particularly among young men who have sex with men (MSM) in urban areas, and the study aimed to understand various factors contributing to this problem, including demographics and clinical aspects.
  • - The research analyzed anonymized data from nearly 10,000 newly diagnosed HIV cases from 2003 to 2019, revealing that 71.2% of participants experienced late diagnosis, with a median CD4 count of 221 cells/μl at diagnosis.
  • - Key factors linked to late HIV diagnosis included older age, heterosexual transmission, living outside of Tokyo, co-infection with hepatitis C, and not being part of a genetic cluster, while a specific HIV subtype (CRF
View Article and Find Full Text PDF
Article Synopsis
  • In late 2022, the SARS-CoV-2 Omicron subvariant XBB emerged from the recombination of two existing BA.2 lineages, BJ.1 and BM.1.1.1, during the summer of 2022.
  • XBB.1 shows strong resistance to vaccines designed for BA.2/5 and has increased fusogenicity, meaning it can fuse with human cells more efficiently due to changes in its spike protein.
  • Research indicates that while XBB.1 is pathogenic, its disease-causing potential in male hamsters is similar to or lower than that of the BA.2.75 variant, marking a notable adaptation in virus evolution through recombination.
View Article and Find Full Text PDF
Article Synopsis
  • In late 2022, several Omicron subvariants emerged globally, characterized by specific amino acid changes in their spike proteins, indicating convergent evolution.
  • The study highlights a problematic lineage, BQ.1.1, which shows higher viral fitness due to five critical amino acid substitutions and better evasion of immune responses compared to the BA.5 subvariant.
  • In tests on hamsters, BQ.1.1 demonstrated lower pathogenicity than BA.5, revealing insights into the evolutionary patterns of Omicron subvariants up to 2022.
View Article and Find Full Text PDF

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) inactivation of pH-dependent graphene oxide (GO) nanosheets is presented. The observed virus inactivation using an authentic virus (Delta variant) and different GO dispersions at pH 3, 7, and 11 suggests that the higher pH of the GO dispersion yields a better performance compared to that of GO at neutral or lower pH. The current findings can be ascribed to the pH-driven functional group change and the overall charge of GO, favorable for the attachment between GO nanosheets and virus particles.

View Article and Find Full Text PDF

Mpox, caused by the mpox virus (MPXV), produces symptoms similar to those of smallpox when transmitted to humans. Since 1970, this disease has been endemic, particularly in Africa. However, since May 2022, the number of patients without a history of travel to endemic areas has increased rapidly globally.

View Article and Find Full Text PDF