Imaizumi Naoki

写真a

Title

Associate Professor

Researcher Number(JSPS Kakenhi)

10547384

Laboratory Address

207 Uehara,Nishihara,Okinawa

Mail Address

E-mail address

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Current Affiliation Organization 【 display / non-display 】

  • Duty   University of the Ryukyus   Faculty of Medicine   Health Sciences   Associate Professor  

  • Concurrently   University of the Ryukyus   Graduate School of Health Sciences   Division of Health Sciences   Associate Professor  

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External Career 【 display / non-display 】

  • 2009.04
    -
    2022.03

     

  • 2009.04
    -
    2022.03

    University of the Ryukyus, Faculty of Medicine, Research Associate  

  • 2022.04
    　
    　

    University of the Ryukyus, Faculty of Medicine, Associate professor  

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Affiliated academic organizations 【 display / non-display 】

  • 　
    　
    　
     

    THE JAPANESE SOCIETY OF TOXICOLOGY 

  • 　
    　
    　
     

    THE JAPANESE SOCIETY FOR THE STUDY OF XENOBIOTICS 

  • 　
    　
    　
     

    JAPANESE ASSOCIATION OF MEDICAL TECHNOLOGISTS 

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Research Interests 【 display / non-display 】

  • Glutathione transferase

  • mitochondria

  • Toxicology

  • HTLV-1 ATL

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Research Areas 【 display / non-display 】

  • Life Science / Clinical pharmacy

  • Life Science / Hematology and medical oncology

  • Life Science / Hematology and medical oncology

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Published Papers 【 display / non-display 】

  • A protective role of HTLV-1 gp46-specific neutralizing and antibody-dependent cellular cytotoxicity-inducing antibodies in progression to adult T-cell leukemia (ATL).

    Tanaka Y, Tanaka R, Imaizumi N, Mizuguchi M, Takahashi Y, Hayashi M, Miyagi T, Uchihara J, Ohshiro K, Masuzaki H, Fukushima T

    Frontiers in immunology ( Frontiers in Immunology )  13   921606   2022.09 [ Peer Review Accepted ]

    Type of publication: Research paper (scientific journal)

    　View Summary

    Human T-cell leukemia virus type-1 (HTLV-1) establishes a long-term persistent infection in humans and causes malignant T-cell leukemia, adult T-cell leukemia (ATL). HTLV-1-specific cytotoxic T lymphocytes have been suggested to play a major role in the immunosurveillance of HTLV-1-infected T cells. However, it remains unclear whether HTLV-1-specific functional antibodies are also involved in the host defense. To explore the role of antibodies in the course of HTLV-1 infection, we quantitated HTLV-1-specific neutralizing and antibody-dependent cellular cytotoxicity (ADCC)-inducing antibody levels in plasma from asymptomatic carriers (ACs) and ATL patients. The levels of neutralizing antibodies, as determined by a syncytium inhibition assay, were significantly lower in acute and chronic ATL patients than in ACs. The levels of ADCC-inducing activity were tested using an autologous pair of HTLV-1-producing cells and cultured natural killer (NK) cells, which showed that the ADCC-inducing activity of IgG at a concentration of 100 µg/ml was comparable between ACs and acute ATL patients. The anti-gp46 antibody IgG levels, determined by ELISA, correlated with those of the neutralizing and ADCC-inducing antibodies. In contrast, the proviral loads did not correlate with any of these antibody levels. NK cells and a monoclonal anti-gp46 antibody reduced the number of HTLV-1 Tax-expressing cells in cultured peripheral blood mononuclear cells from patients with aggressive ATL. These results suggest a protective role for HTLV-1 neutralizing and ADCC-inducing antibodies during the course of HTLV-1 infection.

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  • Acute type adult T-cell leukemia cells proliferate in the lymph nodes rather than in peripheral blood.

    Mizuguchi M, Takatori M, Sakihama S, Yoshita-Takahashi M, Imaizumi N, Takahashi Y, Hasegawa H, Karube K, Fukushima T, Nakamura M, Tanaka Y

    Cancer gene therapy ( Cancer Gene Therapy )    2022.04 [ Peer Review Accepted ]

    Type of publication: Research paper (scientific journal)

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  • Elevation of the Plasma Levels of TNF Receptor 2 in Association with Those of CD25, OX40, and IL-10 and HTLV-1 Proviral Load in Acute Adult T-Cell Leukemia.

    Kato M, Imaizumi N, Tanaka R, Mizuguchi M, Hayashi M, Miyagi T, Uchihara J, Ohshiro K, Todoroki J, Karube K, Masuzaki H, Tanaka Y, Fukushima T

    Viruses ( Viruses )  14 ( 4 ) 751 - 751   2022.04 [ Peer Review Accepted ]

    Type of publication: Research paper (scientific journal)

    　View Summary

    Adult T-cell leukemia/lymphoma (ATL) cells express TNF receptor type-2 (TNFR2) on their surface and shed its soluble form (sTNFR2). We previously reported that sTNFR2 levels were highly elevated in the plasma of patients with acute ATL. To investigate whether its quantitation would be helpful for the diagnosis or prediction of the onset of acute ATL, we examined the plasma levels of sTNFR2 in a large number of specimens obtained from a cohort of ATL patients and asymptomatic human T-cell leukemia virus type 1 (HTLV-1) carriers (ACs) and compared them to those of other candidate ATL biomarkers (sCD25, sOX40, and IL-10) by enzyme-linked immunosorbent assays (ELISA) and HTLV-1 proviral loads. We observed that sTNFR2 levels were significantly elevated in acute ATL patients compared to ACs and patients with other types of ATL (chronic, smoldering, and lymphoma). Importantly, sTNFR2 levels were significantly correlated with those of sCD25, sOX40, and IL-10, as well as proviral loads. Thus, the present study confirmed that an increase in plasma sTNFR2 levels is a biomarker for the diagnosis of acute ATL. Examination of plasma sTNFR2 alone or in combination with other ATL biomarkers may be helpful for the diagnosis of acute ATL.

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  • Clinicopathological features of adult T-cell leukemia/lymphoma with HTLV-1-infected Hodgkin and Reed-Sternberg-like cells.

    Karube K, Takatori M, Sakihama S, Tsuruta Y, Miyagi T, Morichika K, Kitamura S, Nakada N, Hayashi M, Tomori S, Nakazato I, Ohshiro K, Imaizumi N, Kikuti YY, Nakamura N, Morishima S, Masuzaki H, Fukushima

    Blood advances     2021.01 [ Peer Review Accepted ]

    Type of publication: Research paper (scientific journal)

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  • A new diagnostic algorithm using biopsy specimens in adult T-cell leukemia/lymphoma: combination of RNA in situ hybridization and quantitative PCR for HTLV-1.

    Takatori M, Sakihama S, Miyara M, Imaizumi N, Miyagi T, Ohshiro K, Nakazato I, Hayashi M, Todoroki J, Morishima S, Masuzaki H, Fukushima T, Karube K

    Modern pathology : an official journal of the United States and Canadian Academy of Pathology, Inc ( Modern Pathology )    2020.08 [ Peer Review Accepted ]

    Type of publication: Research paper (scientific journal)

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Other Papers 【 display / non-display 】

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SDGs 【 display / non-display 】

  • 沖縄バイオ資源の機能性探索

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