Publications by authors named "Tetsuro Matano"

Post-translational modification of proteins is a crucial biological reaction that regulates protein functions by altering molecular properties. The specific detection of such modifications in proteins has made significant contributions to molecular biology research and holds potential for future drug development applications. In HIV research, for example, tyrosine sulfation at the N-terminus of C-C chemokine receptor type 5 (CCR5) is considered to significantly enhance HIV infection efficiency.

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  • Researchers investigated whether SARS-CoV-2 RNA can be found on the skin of COVID-19 patients by analyzing skin surface lipids (SSLs) collected from their faces.
  • Using RT-PCR, they found that 84.6% of samples tested positive within 5 days of symptom onset, while only 30.4% tested positive between 6-10 days.
  • The study also revealed an increase in specific genes related to the immune response in the skin samples, highlighting a new method for detecting the virus and studying its impact on human health non-invasively.
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Background: Person with human immunodeficiency virus type-1 (PWH) are prone to chronic inflammation due to residual viral production, even with antiretroviral therapy (ART), which increases the risk of age-related diseases. There is also limited information on changes in the intestinal environment of PWH during ART. In this longitudinal study, we investigated changes in the gut microbiota, persistence of chronic inflammation, interactions between the gut environment and inflammation, and metabolic changes in PWH using long-term ART.

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  • Persistent inflammation in people living with HIV (PWH) may influence their immune response to SARS-CoV-2 infection differently than in HIV-uninfected individuals.
  • During a study, proinflammatory cytokine levels were measured in PWH, revealing no significant differences in cytokine levels across various COVID-19 severity levels, unlike in HIV-uninfected individuals where higher levels correlated with severe cases.
  • The findings indicate that PWH are in a heightened inflammatory state but exhibit distinct inflammatory responses to SARS-CoV-2 compared to the general population, possibly due to impairments in their immune cells and existing inflammation.
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Antigen-presenting cells (APCs) play an important role in virus infection control by bridging innate and adaptive immune responses. Macrophages and dendritic cells (DCs) possess various surface receptors to recognize/internalize antigens, and antibody binding can enhance pathogen-opsonizing uptake by these APCs via interaction of antibody fragment crystallizable (Fc) domains with Fc receptors, evoking profound pathogen control in certain settings. Here, we examined phagocytosis-enhancing potential of Fc domains directly oriented on a retroviral virion/virus-like particle (VLP) surface.

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Human T cell leukemia/T-lymphotropic virus type 1 (HTLV-1) infection occurs by cell-to-cell transmission and can induce fatal adult T cell leukemia. Vaccine development is critical for the control of HTLV-1 transmission. However, determining whether vaccine-induced anti-Env antibodies can prevent cell-to-cell HTLV-1 transmission is challenging.

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Dengue virus (DENV) represents a significant global health burden, with 50% of the world's population at risk of infection, and there is an urgent need for next-generation vaccines. Virus-like particle (VLP)-based vaccines, which mimic the antigenic structure of the virus but lack the viral genome, are an attractive approach. Here, we describe a dengue VLP (DENVLP) vaccine which generates a neutralizing antibody response against all four DENV serotypes in 100% of immunized non-human primates for up to 1 year.

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Human immunodeficiency virus (HIV) 1 infection is known to cause gut microbiota dysbiosis. Among the causes is the direct infection of HIV-1 in gut-resident CD4 T cells, causing a cascade of phenomena resulting in the instability of the gut mucosa. The effect of HIV infection on gut microbiome dysbiosis remains unresolved despite antiretroviral therapy.

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  • The study evaluated the LC16m8 vaccine's safety and effectiveness against the monkeypox virus (MPXV) in 50 healthy adults over 168 days.
  • On day 28, the vaccine showed strong immunogenicity, with 72% to 88% seroconversion rates, although these rates declined by day 168.
  • Adverse events were common but mostly mild, and no serious safety issues or cases of monkeypox were reported during the study period.
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Unspliced HIV-1 RNAs function as messenger RNAs for Gag or Gag-Pol polyproteins and progeny genomes packaged into virus particles. Recently, it has been reported that fate of the RNAs might be primarily determined, depending on transcriptional initiation sites among three consecutive deoxyguanosine residues (GGG tract) downstream of TATA-box in the 5' long terminal repeat (LTR). Although HIV-1 RNA transcription starts mostly from the first deoxyguanosine of the GGG tract and often from the second or third deoxyguanosine, RNAs beginning with one guanosine (G1-form RNAs), whose transcription initiates from the third deoxyguanosine, were predominant in HIV-1 particles.

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Objectives In response to the steady rise in the number of cases of mpox in nonendemic countries, starting with an outbreak in the United Kingdom in May 2022, the World Health Organization declared a public health emergency of international concern on July 23, 2022. As of November 13, 2022, seven cases of mpox have been reported in Japan.Methods A community engagement approach was applied to prevent the spread of mpox in Japan.

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T cell immunity is crucial for long-term immunological memory, but the profile of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific memory T cells in individuals who recovered from COVID-19 (COVID-19-convalescent individuals) is not sufficiently assessed. In this study, the breadth and magnitude of SARS-CoV-2-specific T cell responses were determined in COVID-19-convalescent individuals in Japan. Memory T cells against SARS-CoV-2 were detected in all convalescent individuals, and those with more severe disease exhibited a broader T cell response relative to cases with mild symptoms.

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Human T-cell leukemia virus type 1 (HTLV-1) induces chronic asymptomatic latent infection with a substantial proviral load but without significant viral replication . Cumulative studies have indicated involvement of CD8-positive (CD8) cells, including virus-specific CD8 T cells in the control of HTLV-1 replication. However, whether HTLV-1 expression from latently infected cells occurs in the absence of CD8 cells remains unclear.

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Background: The 95-95-95 UNAIDS global strategy was adapted to end the AIDS epidemic by 2030. The target is based on the premise that early detection of HIV-infected persons and linking them to treatment regardless of their CD4 counts will lead to sustained viral suppression. HIV testing strategies to increase uptake of testing in Western and Central Africa remain inadequate.

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  • - 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
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  • Innate immune responses help control SARS-CoV-2 replication, and a specific lactic acid bacteria strain, Lactococcus lactis strain Plasma (LC-Plasma), can activate immune cells called plasmacytoid dendritic cells (pDCs).
  • Research showed that when pDCs are stimulated with LC-Plasma, their secretions can reduce SARS-CoV-2 replication in cell cultures.
  • The study also found that the secretion of interferon-α (IFN-α) from pDCs is crucial to this suppression; blocking IFN-α decreased the effectiveness of LC-Plasma in reducing the virus's replication.
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SARS-CoV-2 continues to spread worldwide. Patients with COVID-19 show distinct clinical symptoms. Although many studies have reported various causes for the diversity of symptoms, the underlying mechanisms are not fully understood.

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  • HLA-B*57:01 and B*58:01 are known as protective alleles against HIV-1, specifically in relation to the TW10 epitope, but their effectiveness in combating the CRF01_AE strain prevalent in Southeast Asia is less understood.
  • A study involving 280 Vietnamese individuals with CRF01_AE infection found that while most HLA-B*57:01/58:01-positive individuals had the T242N mutation, there was no significant improvement in viral load or CD4 counts compared to those without these alleles.
  • Further analysis showed that although T242N reduces the viral fitness of CRF01_AE, the overall protective effect of HLA-B*57:01
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Among western African countries, the Republic of Ghana has maintained an economic growth rate of 5% since the 1980s and is now categorized as a middle-income country. However, as with other developing countries, Ghana still has challenges in the effective implementation of surveillance for infectious diseases. Facing public health emergencies of international concern (PHEIC), it is crucial to establish a reliable sample transportation system to the referral laboratory.

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  • The study focuses on developing macaque-tropic HIV-1 variants (HIV-1mt) to create better primate models for understanding HIV-1 infection and testing new treatment strategies.
  • A specific variant, MN4Rh-3, was found to replicate poorly in cynomolgus macaques, prompting the reconstruction of a new CCR5-tropic variant, AS38, via serial passages.
  • The adapted AS38 variant showed significantly higher viral loads during acute infection and prolonged viremia, with a key genetic deletion linked to increased Vpr protein expression, indicating its importance in the adaptation process.
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Expanding access to effective antiretroviral therapy (ART) is a major tool for management of Human Immunodeficiency Virus (HIV) infection. However, rising levels of HIV drug-resistance have significantly hampered the anticipated success of ART in persons living with HIV (PLWH), particularly those from Africa. Though great strides have been made in Ghana toward achieving the UNAIDS "95-95-95" target, a substantial number of PLWH receiving ART have not attained viral suppression.

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Determinants of memory T cell longevity following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection remain unknown. In addition, phenotypes associated with memory T cell longevity, antibody titers, and disease severity are incompletely understood. Here, we longitudinally analyzed SARS-CoV-2-specific T cell and antibody responses of a unique cohort with similar numbers of mild, moderate, and severe coronavirus disease 2019 cases.

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  • The study examines how specific B-cell responses to the HIV-1 virus and the variability of the virus's Envelope (Env) are connected in treatment-naive Vietnamese individuals with HIV-1 CRF01_AE strains.
  • By analyzing samples from both acute and chronic phases of infection, researchers found that plasma cell responses significantly correlated with the genetic variations in the Env, particularly in chronic cases.
  • Findings suggest that the B-cells' immune response exerts selective pressure on the HIV Env, influencing its diversification due to the diverse antibody responses generated during infection.
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Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been transmitted across all over the world, in contrast to the limited epidemic of genetically- and virologically-related SARS-CoV. However, the molecular basis explaining the difference in the virological characteristics among SARS-CoV-2 and SARS-CoV has been poorly defined. Here we identified that host sialoglycans play a significant role in the efficient spread of SARS-CoV-2 infection, while this was not the case with SARS-CoV.

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Diarrheal disease remains a major global health problem particularly in children under 5 years and the emergence of antibiotic-resistant strains of causative pathogens could slow control efforts, particularly in settings where treatment options are limited. This surveillance study conducted in Ghana aimed to determine the prevalence and antimicrobial susceptibility profile of diarrhea-causing bacteria. This was a cross-sectional study carried out in five health facilities in the Ga West Municipality of Ghana between 2017 and 2021.

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