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Japan Academy Prize to:Hiroshi Kiyono
Director, Synergy Institute for Futuristic Mucosal
Vaccine Research and Development (cSIMVa),Chiba University
Head of Division, Division of Infectious Disease
Vaccine R&D, Research Institute of DisasterMedicine, Chiba University
Adjunct Professor, Department of Medicine,
UC San Diego School of Medicine,
University of California, San Diego, USA
Professor Emeritus, The University of Tokyo
Adjunct Professor, La Jolla Institute for Immunology, USAfor “Starting with Caries Vaccine Research, Establishing Mucosal
Immunology and Developing Oral and Nasal Vaccines”

Outline of the work:
Following the identification of Streptococcus mutans as the causative agent behind dental
caries (one of the two major oral diseases, alongside periodontal diseases) in the 1970s, Dr.
Hiroshi Kiyono embarked on his research career. Fresh out of dental school in Japan, he joineda research team in the United States studying the role of S . mutans in the development of caries
vaccines. While the initial goal of caries vaccine development was not achieved, Dr. Kiyono’s
work with his colleagues demonstrated that oral immunization using haptenized S . mutans could
induce antigen (Ag)-specific IgA and IgG antibodies. This pioneering research not only laid thefoundation for his future exploration of mucosal immunity regulation but also contributed to theadvancement of the field itself.
Given the prevailing belief that Peyer’s patches (PPs) in the intestine were responsible for
initiating Ag-specific IgA responses, Dr. Kiyono and his colleagues focused their research onthese issues. They developed a groundbreaking enzymatic cell isolation method from PPs, enabling the demonstration of antigen-presenting cells within them. These cells play a vital role ininitiating Ag-specific immune responses. He further leveraged T cell cloning technology to identify IgA isotype-specific Th cells within the PPs. These specialized T helper cells preferentiallyinduce and regulate Ag-specific IgA antibody responses. This finding definitively established
PPs as a site for initiating Ag-specific immune responses.
Dr. Kiyono’s team further elucidated the critical role of antigen uptake through the development of a monoclonal antibody, NKM16-2-4, targeting antigen-sampling M cells within the PPepithelium. This antibody was then used to create a chimeric Ag by coupling it with botulinum
toxoid (BT). Oral administration of the chimeric antigen consisting with NKM-16-2-4 and BT

35to mice resulted in eﬃcient uptake by M cells, subsequently inducing Ag-specific IgA and IgG
antibodies that neutralize botulinum toxin. The M cell-specific antibodies revealed their presence
beyond PPs, also residing within the villous epithelium. This finding not only underscored theeﬃcacy of Ag delivery to M cells but also highlighted the diversity of mucosal antigen samplingsystems, contributing to the scientific foundation for oral vaccine development.
Dr. Kiyono’s research extended beyond the well-studied intestine’s mucosal immune system
to the less-explored respiratory system. The nasopharyngeal-associated lymphoid tissue (NALT),a target for nasal immunization, mirrors the function of PPs in the gut. Interestingly, M cells werealso found in the NALT’s epithelial layer. Furthermore, Dr. Kiyono’s work revealed the presenceof M cells not only in the NALT epithelium but also in the nasal cavity epithelium, similar to theirdistribution in the intestinal villous layer. Dr. Kiyono’s research further revealed the presenceof immunocompetent cells within the NALT, essential for inducing and regulating Ag-specificimmune responses. These findings significantly contributed to establishing a strategic foundation
for the development of nasal vaccines.
Using an interdisciplinary approach encompassing medicine, agriculture, and plant engineering, Dr. Kiyono’s team pioneered a novel rice-based oral vaccine platform called “MucoRice.” This innovative approach oﬀers a cold-chain and needle-free solution for mucosal
vaccine delivery. MucoRice-engineered rice expressing the B subunit of cholera toxin (CTB),
essential for the toxin binding to epithelial cells, eﬀectively induces antigen-specific IgA antibodies with the toxin-neutralizing capability upon oral administration in the experimental animals.
A subsequent Phase I clinical trial in healthy Japanese volunteers employed a dose-escalation
design to evaluate MucoRice-CTB. This study demonstrated a dose-dependent increase of Agspecific antibodies, supporting its immunogenicity as a human oral vaccine. To further confirm
these findings and assess safety in a broader population, a separate Phase I trial was conducted inhealthy, racially diverse U.S volunteers.
Dr. Kiyono’s research also encompassed nasal vaccine development. To address the negatively charged nature of the nasal mucosa’s epithelial layer, his team, in collaboration withbiomaterial engineers, developed a cationic cholesteryl-group-bearing pullulan nanogel (cCHP)
capable of encapsulating proteins. This innovative carrier system allowed the encapsulated antigen to adhere to the nasal epithelium for a prolonged period after administration, facilitating efficient delivery to the immunocompetent cells residing beneath the epithelial layer. Intriguingly,
nasal immunization with the encapsulated pneumococcal surface protein A from Streptococcus
pneumonia within cCHP elicited Ag-specific IgA and IgG antibodies in experimental animals,
eﬀectively inhibiting the development of pneumonia.
Dr. Kiyono’s research initiated dentistry and led to groundbreaking discoveries in the mucosal immune system and the development of innovative mucosal vaccines. His influence extends
beyond national borders, as evidenced by his leadership positions in prestigious scientific societies, serving as president of the Japanese Society for Vaccinology, the Japanese Society forImmunology, the Society for Mucosal Immunology, and the Intestinal Microbiology Society. A
tireless advocate for mucosal immunology research, Dr. Kiyono has not only shaped academic
fields and research directions but also championed the development of practical applications. His
achievements and dedication to the field are highly respected worldwide.

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List of Main Publications
1. Kiyono, H., McGhee, J.R. and Michalek, S.M. 1980. Lipopolysaccharide regulation of theimmune response: comparison of responses to LPS in germfree, Escherichia coli - monoassociated and conventional mice. J. Immunol. 124: 36–41.
2. Kiyono, H., McGhee, J.R., Wannemuehler, M.J., Frangakis, M.V., Spalding, D.M.,
Michalek, S.M. and Koopman, W.J. 1982. In vitro responses to a T-dependent antigen bydisassociated Peyer’s patch cultures. Proc. Natl. Acad. Sci. U.S.A. 79: 596–600.
3. Kiyono, H., McGhee, J.R., Mosteller, L.M., Eldridge, J.H., Koopman, W.J., Kearney, J.F.
and Michalek, S.M. 1982. Murine Peyer’s patch T cell clones: characterization of antigenspecific helper T cells for immunoglobulin A responses. J. Exp. Med. 156: 1115–1130.
4. Kiyono, H., Cooper, M.D., Kearney, J.F., Mosteller, L.M., Michalek, S.M., Koopman, W.J.
and McGhee, J.R. 1984. Isotype-specificity of helper T cell clones: Peyer’s patch Th cells
preferentially collaborate with mature IgA B cells for IgA responses. J. Exp. Med. 159:798–811.
5. Fukuyama, S., Hiroi, T., Yokota, Y., Rennert, P.D., Yanagita, M., Kinoshita, N., Terawaki, S.,Shikina, T., Yamamoto, M., Kurono, Y. and Kiyono, H. 2002. Initiation of NALT organogenesis is independent of the IL-7R, LTßR and NIK signaling pathways, but requires the Id2
gene and CD3− CD4+ CD45+ cells. Immunity 17: 31–40.
6. Jang, M.H., Kweon, M.N., Iwatani, K., Yamamoto, M., Terahara, K., Sasakawa, C., Suzuki,T., Nochi, T., Yokota, Y., Hiroi, T., Tamagawa, H., Iijima, H., Kunisawa, J., Yuki, Y. and Kiyono, H. 2004. Intestinal villous M cells: A new antigen entry site in the mucosal epithelium.
Proc. Natl. Acad. Sci. U.S.A. 101: 6110–6115.
7. Kiyono, H. and Fukuyama, S. 2004. NALT-versus Peyer’s patch-mediated mucosal immunity. Nat. Rev. Immunol. 4: 699–710.
8. Nochi, T., Yuki, Y., Matsumura, A., Mejima, M., Terahara, K., Kim, D.Y., Fukuyama, S.,
Iwatsuki-Horimoto, K., Kawaoka, Y., Igarashi, O. and Kiyono, H. 2007. A novel M-cellspecific carbohydrate-targeted mucosal vaccine induces eﬀectively antigen-specific immuneresponses. J. Exp. Med. 204: 2789–2796.
9. Terahara, K., Yoshida, M., Igarashi, O., Nochi, T., Pontes, G.S., Hase, K., Ohno, H.,Kurokawa, S., Mejima, M., Takayama, N., Yuki, Y., Lowe, A.W. and Kiyono, H. 2008.
Comprehensive gene expression analysis among Peyer’s patch M cells, villous M cells andintestinal epithelial cells by DNA microarray analysis. J. Immunol. 180: 7840–7846.
10. Nagatake, T., Fukuyama, S, Kim. D.Y., Gohda, K., Igarashi. O., Sato, S., Nochi, T., Sagara,H., Yokota, Y., Jetten, A.M., Kaisho, T., Akira, A., Mimuro, H., Sasakawa, C., Fukui, Y.,Fujihashi, K., Akiyama, T., Inoue, J., Penninger, J.M., Kunisawa, J. and Kiyono, H. 2009.
Id2-, RORγt-, and LTßR-independent lymphoid organogenesis in ocular immunity. J. Exp.
Med. 206: 2351–2364.
11. Kim, D.Y., Sato, A., Fukuyama, S., Sagara, H, Nagatake, T., Kong, I.G., Goda, K., Nochi,T., Kunisawa, J., Sato, S., Yokota, Y., Lee, C.H. and Kiyono, H. 2011. The airway antigensampling system: Respiratory M cells as an alternative gateway for inhaled antigens. J.
Immunol. 186: 4253–4262 (Cover page article).

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12. Kurashima, Y., Amiya, T., Nochi, T., Fujisawa, K., Haraguchi, T., Iba, H., Tsutsui, H., Sato,
S., Nakajima, S., Iijima, H., Kunisawa, J. and Kiyono, H. 2012. Extracellular ATP mediates
mast cell–dependent intestinal inflammation through P2X7 purino receptors. Nat. Commun.
3: 1034.
13. Obata, T., Goto, Y., Kunisawa, J., Sato, S., Sakamoto, M., Setoyama, H., Matsuki, T., Nonaka, K., Shibata, N., Gohda, M., Kagiyama, Y., Nochi, T., Yuki, Y., Fukuyama, Y., Mukai,A., Shinzaki, S., Fujihashi, K., Sasakawa, C., Iijima, H., Goto, M., Umesaki, Y., Benno, Y.
and Kiyono, H. 2010. Indigenous opportunistic bacteria inhabit mammalian gut-associatedlymphoid tissues and share a mucosal antibody-mediated symbiosis. Proc. Natl. Acad. Sci.
U.S.A. 107: 7419–7424.
14. Goto, Y., Obata, T., Kunisawa, J., Sato, S., Ivanov, I., Lamichhane, A., Takeyama, N.,
Kamioka, M., Sakamoto, M., Matsuki, T., Setoyama, H., Imaoka, A., Uematsu, S., Akira,S., Domino, S., Kulig, P., Becher, B., Renauld, J-C., Sasakawa, C., Umesaki, Y., Benno, Y.
and Kiyono, H. 2014. Innate lymphoid cells regulate intestinal epithelial cell glycosylation.
Science 345: 1254009.
15. Goto,Y., Uematsu, S. and Kiyono, H. 2016. Epithelial glycosylation in gut homeostasis andinflammation. Nat. Immunol. 17: 1244–1251.
16. Kurashima, Y. and Kiyono, H. 2017. Mucosal ecological network of epithelium and immune
cells for gut homeostasis and tissue healing. Annu. Rev. Immunol. 35: 119–147.
17. Kurashima, Y., Kigoshi, T., Murasaki, S., Arai, F., Shimada, K., Seki, N., Kim, Y.G., Hase,K., Ohno, H., Kawano, K., Ashida, H., Suzuki, T., Morimoto, M., Saito, Y., Sasou, A., Goda,Y., Yuki, Y., Inagaki, Y., Iijima, H., Suda, W., Hattori, M. and Kiyono, H. 2021. Pancreatic
glycoprotein 2 is a first line of defense for mucosal protection in intestinal inflammation.
Nat. Commun. 12: 1067.
18. Kamioka, M., Goto, Y., Nakamura, K., Yokoi, Y., Sugimoto, R., Ohira, S., Kurashima, Y.,Umemoto, S., Sato, S., Kunisawa, J., Takahashi, Y., Domino, S.E., Renauld, J-C., Nakae, S.,
Iwakura, Y., Ernst, P.B., Ayabe, T. and Kiyono, H. 2022. Intestinal commensal microbiota
and cytokines regulate Fut2+ Paneth cells for gut defense. Proc. Natl. Acad. Sci. U.S.A.
119: e2115230119.
19. Nochi, T., Takagi, H., Yuki, Y., Yang, L., Masumura, T., Mejima, M., Nakanishi, U., Matsumura, A., Uozumi, A., Hiroi, T., Morita, S., Tanaka, K., Takaiwa, F. and Kiyono, H. 2007.
Rice-based mucosal vaccine as a global strategy for cold-chain- and needle-free vaccination.
Proc. Natl. Acad. Sci. U.S.A. 104: 10986–10991.
20. Nochi, T., Yuki, Y., Katakai, Y., Shibata, H., Tokuhara, D., Mejima, M., Kurokawa, S.,
Takahashi, Y., Nakanishi, U., Ono, F., Mimuro, H., Sasakawa, C., Takaiwa, F., Terao, K.
and Kiyono, H. 2009. A rice-based oral cholera vaccine induces macaque-specific systemic
neutralizing Abs but does not influence pre-existing intestinal immunity. J. Immunol. 183:6538–6544.
21. Tokuhara, D., Yuki, Y., Nochi, T., Kodama, T., Mejima, M., Kurokawa, S., Takahashi, Y.,Nanno, M., Nakanishi, U., Takaiwa, F., Honda, T. and Kiyono, H. 2010. Secretory IgAmediated protection against V. cholerae and heat-labile enterotoxin-producing enterotoxigenic Escherichia coli by rice-based vaccine. Proc. Natl. Acad. Sci. U.S.A. 107: 8794–388799.
22. Nochi, T., Yuki, Y., Takahashi, H., Sawada, S. I., Mejima, M., Kohda, T., Harada, N.,Kong, I.G., Sato, A., Kataoka, N., Tokuhara, D., Kurokawa, S., Takahashi, Y., Tsukada, H.,
Kozaki, S., Akiyoshi, K. and Kiyono, H. 2010. Nanogel antigenic protein-delivery system
for adjuvant-free intranasal vaccines. Nat. Mater. 9: 572–578.
23. Kong, I.G., Sato, A., Yuki, Y., Nochi, T., Takahashi, H., Sawada, S., Mejima, M., Kurokawa,S., Okada, K., Sato, S., Briles, D.E., Kunisawa, J., Inoue, Y., Yamamoto, M., Akiyoshi, K.
and Kiyono, H. 2013. Nanogel-based PspA intranasal vaccine prevents invasive disease andnasal colonization by Streptococcus pneumoniae. Infect. Immun. 81: 1625–1634.
24. Fukuyama, Y., Yuki, Y., Katakai, Y., Harada, N., Takahashi, H., Takeda, S., Mejima, M., Joo,S., Kurokawa, S., Sawada, S., Shibata, H., Park, E.J., Fujihashi, K., Briles, D.E., Yasutomi,Y., Tsukada, H., Akiyoshi, K. and Kiyono, H. 2015. Nanogel-based pneumococcal surface
protein A nasal vaccine induces microRNA-associated Th17 cell responses with neutralizing
antibodies against Streptococcus pneumoniae in macaques. Mucosal Immunol. 8: 1144–1153.
25. Yuki, Y., Nojima, M., Hosono, O., Tanaka, H., Kimura, Y., Satoh, T., Imoto, S., Uematsu,
S., Kurokawa, S., Kashima, K., Mejima, M., Nakahashi-Ouchida, R., Uchida, Y., Marui,T., Yoshikawa, N., Nagamura, F., Fujihashi, K. and Kiyono, H. 2021. Assessment of oral
MucoRice-CTB vaccine for the safety and microbiota-dependent immunogenicity in humans: A randomized trial. Lancet Microbe. 2: e429–e440.
26. Yuki, Y., Nojima, Kashima, K., Sugiura, K., Maruyama, S., Kurokawa, S., Yamanoue, T.,
Nakahashi-Ouchida, R., Nakajima, H., Hiraizumi, T., Kohno, H., Goto, E., Fujihashi, K.
and Kiyono, H. 2022. Oral MucoRice-CTB vaccine is safe and immunogenic in healthy US
adults. Vaccine 40: 3372–3379.
27. Umemoto, S., Nakahashi-Ouchida, R., Yuki, Y., Kurokawa, S., Machita, T., Uchida, Y.,Mori, H., Yamanoue, T., Shibata, T., Sawada, S., Ishige, K., Hirano, T., Fujihashi, K.,
Akiyoshi, K., Kurashima, Y., Tokuhara, D., Ernst, P.B., Suzuki, M. and Kiyono, H. 2023.
Cationic-nanogel nasal vaccine containing the ectodomain of RSV-small hydrophobic protein induces protective immunity in rodents. NPJ Vaccines 8: 106.
28. Nakahashi-Ouchida, R., Fujihashi, K., Kurashima, Y., Yuki, Y. and Kiyono, H. 2023. Nasal
vaccines: solutions for respiratory infectious diseases. Trends. Mol. Med. 29: 124–140.