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Biochemistry and Molecular Biology(Biology)

Tachibana MasashiSpecially Appointed Assosiate Professor

I've been working hard on my research at Osaka Univ. (B & M course), at Yokohama City Univ. (PhD course), and then at RIKEN. I hope to turn today's unknowns into tomorrow's knowledge, and I am working under the motto " Have fun doing research”.

Research theme

Elucidation of immunosuppressive mechanisms in tumors and their application to novel therapies

Immunosuppressive environments in tumors inhibit the natural anti-tumor immunity. Myeloid-derived suppressor cells (MDSCs) suppress the anti-tumor immunity and promote tumor progression. Since MDSCs are present in high numbers in patients who do not respond to immune checkpoint blockade therapy, targeting MDSCs is expected to be an innovative therapy that functions in the different manner from immune checkpoint blockade therapy. We are working on elucidating the mechanisms of differentiation, proliferation, and immunosuppressive function of MDSCs toward the development of cancer therapy targeting MDSCs.

Development of novel mucosal vaccine adjuvants

Vaccines against SARS-CoV-2 have been shown to be highly effective, and this is speculated to be due to their superior ability to induce cellular immunity. Since helper T cells play important roles in the activation of cellular immunity, vaccine adjuvants that target helper T cells will be necessary for future pandemics. Previous adjuvants have targeted myeloid cells, but we are aiming to develop vaccine adjuvants based on a new concept of regulating helper T cell differentiation.

Representative achievements

Tachibana M*,#, Watanabe N*, Koda Y*, Oya Y, Kaminuma O, Katayama K, Fan Z, Sakurai F, Kawabata K, Hiroi T#, Mizuguchi H#. (*contributed equally, #co-corresponding author)
Ablation of IL-17A leads to severe colitis in IL-10-deficient mice: implications of myeloid-derived suppressor cells and NO production.
Int Immunol. 2020;32(3):187-201.

Xie Z, Ikegami T, Ago Y, Okada N, Tachibana M. (corresponding author)
Valproic acid attenuates CCR2-dependent tumor infiltration of monocytic myeloid-derived suppressor cells, limiting tumor progression.
Oncoimmunology, 2020;9(1): 1734268.

Morikawa N*, Tachibana M*,#, Ago Y, Goda H, Sakurai F, Mizuguchi H#. (*contributed equally, #co-corresponding author)
LY341495, an mGluR2/3 antagonist, regulates the immunosuppressive function of myeloid-derived suppressor cells and inhibits melanoma tumor growth.
Biol Pharm Bull, 2018; 41(12):1866-1869.

Xie Z, Ago Y, Okada N, Tachibana M. (corresponding author)
Valproic acid attenuates immunosuppressive function of myeloid-derived suppressor cells.
J Pharmacol Sci, 2018; 137(4):359-365.

Hemmi M*, Tachibana M*,#, Fujimoto N, Shoji M, Sakurai F, Kobiyama K, Ishii KJ, Akira S, Mizuguchi H#. (*contributed equally, #co-corresponding author)
T Helper 17 Promotes Induction of Antigen-Specific Gut-Mucosal Cytotoxic T Lymphocytes following Adenovirus Vector Vaccination.
Front Immunol. 2017; 8:1456.

Hayatsu N*, Miyao T*, Tachibana M, Murakami R, Kimura A, Kato T, Kawakami E, Endo TA, Setoguchi R, Watarai H, Nishikawa T, Yasuda T, Yoshida H, Hori S. (*contributed equally)
Analyses of a Mutant Foxp3 Allele Reveal BATF as a Critical Transcription Factor in the Differentiation and Accumulation of Tissue Regulatory T Cells.
Immunity, 2017; 47(2):268-283.e9.

Tsuzuki S*, Tachibana M*, Hemmi M, Yamaguchi T, Shoji M, Sakurai F, Kobiyama K, Kawabata K, Ishii KJ, Akira S, Mizuguchi H. (*contributed equally)
TANK-binding kinase 1-dependent or -independent signaling elicits the cell-type-specific innate immune responses induced by the adenovirus vector.
Int Immunol. 2016; 28(3):105-15.

Tachibana M, Tenno M, Tezuka C, Sugiyama M, Yoshida H, Taniuchi I.
Runx1/Cbf2 complexes are required for lymphoid tissue inducer cell differentiation at two developmental stages.
J Immunol., 2011; 186(3):1450-7.

Tachibana M, Wada K, Katayama K, Kamisaki Y, Maeyama K, Kadowaki T, Blumberg RS, Nakajima A.
Activation of peroxisome proliferator-activated receptor  suppresses mast cell maturation involved in allergic diseases.
Allergy, 2008; 63(9):1136-47.

Setoguchi R*, Tachibana M*, Naoe Y*, Muroi S, Akiyama K, Tezuka C, Okuda T, Taniuchi I. (*contributed equally)
Repression of the transcription factor Th-POK by Runx complexes in cytotoxic T cell development.
Science, 2008; 319(5864):822-5.