23

Department of Microbiology and Immunology

Division of Vaccine Science
ワクチン科学分野
Professor
Associate Professor
Assistant Professor
Assistant Professor

Ken Ishii, M.D., Ph.D.
Kouji Kobiyama, Ph.D.
Burcu Temizoz, Ph.D.
Tomoya Hayashi, Ph.D.

教 授
准教授
助 教助 教博士（医学）
博士（医学）
博士（医学）
博士（医学）石 井健
小檜山 康 司テミズオズ ブルジュ林
智 哉

Primary goal of our laboratory is to understand the immunological mechanisms of
the intra- and inter-cellular signaling pathways that mediate the immunogenicity ofsuccessful vaccines, as well as biological responses to adjuvants. Such knowledge
will enable us to develop novel concepts, modalities and next generation immunopreventive and/or therapeutic agents against infectious diseases, cancer andallergy as well as other non-communicable diseases.

A squalene-based emulsion adjuvant, induces T
follicular helper cells and humoral immune responses via α-tocopherol component
Adjuvants are chemical or biological materials thatenhance the efficacy of vaccines. A-910823 is a squalenebased emulsion adjuvant used for S-268019-b, a novel
vaccine against severe acute respiratory syndrome
coronavirus 2 (SARS-CoV-2) that is currently in clinical development. Published evidence has demonstrated that A-910823 can enhance the induction ofneutralizing antibodies against SARS-CoV-2 in humans and animal models. However, the characteristics and mechanisms of the immune responses induced by A-910823 are not yet known. To characterize
A-910823, we compared the adaptive immune response profile enhanced by A-910823 with that of other adjuvants (AddaVax, QS21, aluminum salt-based
adjuvants, and empty lipid nanoparticle [eLNP]) in amurine model. Compared with other adjuvants,A-910823 enhanced humoral immune responses to an
equal or greater extent following potent T follicularhelper (Tfh) and germinal center B (GCB) cell induction, without inducing a strong systemic inflammatory cytokine response. Furthermore, S-268019-b containing A-910823 adjuvant produced similar results

even when given as a booster dose following primaryadministration of a lipid nanoparticle-encapsulated
messenger RNA (mRNA-LNP) vaccine. Preparationof modified A-910823 adjuvants to identify which
components of A-910823 play a role in driving the adjuvant effect and detailed evaluation of the immunological characteristics induced by each adjuvant
showed that the induction of humoral immunity andTfh and GCB cell induction in A-910823 were dependent on α-tocopherol. Finally, we revealed that the recruitment of inflammatory cells to the draining lymph
nodes and induction of serum cytokines and chemokines by A-910823 were also dependent on the α-tocopherol component. This study demonstrates thatthe novel adjuvant A-910823 is capable of robust Tfh
cell induction and humoral immune responses, evenwhen given as a booster dose. The findings also emphasize that α-tocopherol drives the potent Tfh-inducing adjuvant function of A-910823. Overall, ourdata provide key information that may inform thefuture production of improved adjuvants.
Dendritic cell proliferation by primary cilium in atopic dermatitis
Atopic dermatitis (AD) is a common allergic ecze-24
ma that affects up to 10% of adults in developed countries. Immune cells in the epidermis, namely, Langerhans cells (LCs), contribute to the pathogenesis of AD,
although their exact role(s) in disease remain unclear.
We performed immunostaining on human skin andperipheral blood mononuclear cells (PBMCs) and visualized primary cilium. Result and discussion: We
show that human dendritic cells (DCs) and LCs havea previously unknown primary cilium-like structure.
The primary cilium was assembled during DC proliferation in response to the Th2 cytokine GM-CSF, andits formation was halted by DC maturation agents.
This suggests that the role of primary cilium is totransduce proliferation signaling. The platelet-derived growth factor receptor alpha (PDGFRα) pathway, which is known for transducing proliferation
signals in the primary cilium, promoted DC proliferation in a manner dependent on the intraflagellartransport (IFT) system. We also examined the epidermal samples from AD patients, and observed aberrantly ciliated LCs and keratinocytes in immatureand proliferating states. Our results identify a potential relationship between the primary cilium and allergic skin barrier disorders, and suggest that targeting the primary cilium may contribute to treating AD.
Challenges in developing personalized neoantigen cancer vaccines
The recent success of cancer immunotherapies has
highlighted the benefit of harnessing the immune system for cancer treatment. Vaccines have a long historyof promoting immunity to pathogens and, consequently, vaccines targeting cancer neoantigens havebeen championed as a tool to direct and amplify immune responses against tumours while sparing
healthy tissue. In recent years, extensive preclinicalresearch and more than one hundred clinical trials
have tested different strategies of neoantigen discovery and vaccine formulations. However, despite theenthusiasm for neoantigen vaccines, proof of unequivocal efficacy has remained beyond reach for themajority of clinical trials. In this Review, we focus on

the key obstacles pertaining to vaccine design and tumour environment that remain to be overcome in order to unleash the true potential of neoantigen vaccines in cancer therapy.
The 100 Days Mission: how a new medical-countermeasures network can deliver equity and innovation
As shown during the response to COVID-19, thefaster we can develop safe, effective and affordable
vaccines, therapeutics and diagnostics for an escalating infectious disease, the more lives we can save. As
the scientific advisory member for CEPI as well as
IPPS and STEG for G7, Ken Ishii is committed to contribute to the 100 days mission. The goal of the 100Days Mission is to prepare as much as possible so thatwithin the first 100 days that a pandemic threat isidentified, the following interventions can be madeavailable, safe, effective, and affordable:
Accurate and approved rapid point of care diagnostictests
An initial regimen of therapeutics
Vaccines ready to be produced at scale for global deployment
In June 2021, G7 Leaders welcomed the “100 Days
Mission’’ (100DM) in Carbis Bay, building on the collaborative scientific efforts which led to the development of Diagnostics, Therapeutics, and Vaccines(DTVs) for COVID-19. The 1st 100 Day mission report
was authored by scientific, governmental and industry experts drawn from within and beyond the G7. It
proposed 25 recommendations to harness scientificinnovation and strengthen public and private collaboration that will reduce the time from discovery todeployment of DTVs within 100 days of the next pandemic threat.
In order to deliver on these ambitions, G7 scientific advisers called for the establishment of an International Pandemic Preparedness Secretariat (‘the Secretariat’) to support implementation and catalysescientific exchange on the progress of the 100DM.

Publication
1.		Castro Eiro MD, Hioki K, Li L, Wilmsen MEP,Kiernan CH, Brouwers-Haspels I, van Meurs M,Zhao M, de Wit H, Grashof DGB, van de Werken
HJG, Mueller YM, Schliehe C, Temizoz B, Kobiyama K, Ishii KJ, Katsikis PD. TLR9 plus STING
Agonist Adjuvant Combination Induces Potent
Neopeptide T Cell Immunity and Improves Immune Checkpoint Blockade Efficacy in a Tumor
Model. J Immunol. 2023 Dec 8:ji2300038. doi:
10.4049/jimmunol.2300038.
2.		Muranishi K, Kinoshita M, Inoue K, Ohara J, Mihara T, Sudo K, Ishii KJ, Sawa T, Ishikura H. Anti-body Response Following the Intranasal Administration of SARS-CoV-2 Spike Protein-CpG
Oligonucleotide Vaccine. Vaccines (Basel). 2023
Dec 20;12(1):5. doi: 10.3390/vaccines12010005.
3.		Palacpac NMQ, Ishii KJ, Arisue N, Tougan T, Horii
T. Immune tolerance caused by repeated P. falciparum infection against SE36 malaria vaccine candidate antigen and the resulting limited polymorphism. Parasitol Int. 2024 Apr;99:102845. doi:
10.1016/j.parint.2023.102845.
4.		Yokota C, Fujimoto K, Yamakawa N, Kono M, Miyaoka D, Shimohigoshi M, Uematsu M, Watanabe25M, Kamei Y, Sugimoto A, Kawasaki N, Yabuno T,Okamura T, Kuroda E, Hamaguchi S, Sato S, Hotomi M, Akeda Y, Ishii KJ, Yasutomi Y, Sunami K,Uematsu S. Prime-boost-type PspA3 + 2 mucosal
vaccine protects cynomolgus macaques from intratracheal challenge with pneumococci. Inflamm
Regen. 2023 Nov 15;43(1):55. doi: 10.1186/s41232023-00305-2.
5.		Ouédraogo A, Bougouma EC, Palacpac NMQ,
Houard S, Nebie I, Sawadogo J, Berges GD, Soulama I, Diarra A, Hien D, Ouedraogo AZ, KonatéAT, Kouanda S, Myoui A, Ezoe S, Ishii KJ, Sato T,
D’Alessio F, Leroy O, Tiono AB, Cousens S, HoriiT, Sirima SB. Safety and immunogenicity of BKSE36/CpG malaria vaccine in healthy Burkinabe
adults and children: a phase 1b randomised, controlled, double-blinded, age de-escalation trial.
Front Immunol. 2023 Oct 16;14:1267372. doi:
10.3389/fimmu.2023.1267372.
6.		Wang Y, Morishima T, Sezaki M, Sato R, Nakato
G, Fukuda S, Kobiyama K, Ishii KJ, Li Y, Takizawa
H. Akkermansia muciniphila induces slow extramedullary hematopoiesis via cooperative IL1R/TLR signals. EMBO Rep. 2023 Dec 6;24(12):e57485. doi: 10.15252/embr.202357485.
7.		Yao L, Chemaitelly H, Goldman E, Gudina EK,Khalil A, Ahmed R, James AB, Roca A, Fallah MP,Macnab A, Cho WC, Eikelboom J, Qamar FN,
Kremsner P, Oliu-Barton M, Sisa I, Tadesse BT,Marks F, Wang L, Kim JH, Meng X, Wang Y, FlyAD, Wang CY, Day SW, Howard SC, Graff JC,Maida M, Ray K, Franco-Paredes C, Mashe T,
Ngongo N, Kaseya J, Ndembi N, Hu Y, Bottazzi
ME, Hotez PJ, Ishii KJ, Wang G, Sun D, Aleya L,Gu W. Time to establish an international vaccine
candidate pool for potential highly infectious respiratory disease: a community’s view. EClinicalMedicine. 2023 Sep 26;64:102222. doi: 10.1016/j.
eclinm.2023.102222.
8.		Katsikis PD, Ishii KJ, Schliehe C. Challenges in developing personalized neoantigen cancer vaccines. Nat Rev Immunol. 2023 Oct 2. doi: 10.1038/
s41577-023-00937-y.
9.		Dzau V, Swaminathan S, Baker C, Bright RA, Castillo J, Chuan TC, Draghia-Akli R, Eardley-Patel R,Gao GF, Ishii K, Tebeje YK, Lambe T, Machingaidze S, Røttingen JA, Shaligram U, Simão M,Swarup R, Toussaint JF, Wairagkar NS. The 100
Days Mission: how a new medical-countermeasures network can deliver equity and innovation.
Lancet. 2023 Oct 28;402(10412):1507-1510. doi:
10.1016/S0140-6736(23)01775-0.
10.	Zhuo SH, Noda N, Hioki K, Jin S, Hayashi T, Hiraga K, Momose H, Li WH, Zhao L, Mizukami T,Ishii KJ, Li YM, Uesugi M. Identification of a
Self-Assembling Small-Molecule Cancer Vaccine
Adjuvant with an Improved Toxicity Profile.
J Med Chem. 2023 Sep 28;66(18):13266-13279. doi:
10.1021/acs.jmedchem.3c01252.

11.	Konaka H, Kato Y, Hirano T, Tsujimoto K, Park J,Koba T, Aoki W, Matsuzaki Y, Taki M, Koyama S,
Itotagawa E, Jo T, Hirayama T, Kawai T, Ishii KJ,Ueda M, Yamaguchi S, Akira S, Morita T, Maeda
Y, Nishide M, Nishida S, Shima Y, Narazaki M,
Takamatsu H, Kumanogoh A. Secretion of mitochondrial DNA via exosomes promotes inflammation in Behçet’s syndrome. EMBO J. 2023 Oct
16;42(20):e112573. doi: 10.15252/embj.2022112573.
12.	Khazaei Monfared Y, Mahmoudian M, Zakeri-Milani P, Cecone C, Hayashi T, Ishii KJ, Conde J, Matencio A, Trotta F. Intratumoural Delivery ofmRNA Loaded on a Cationic Hyper-Branched Cyclodextrin-Based Polymer Induced an Anti-Tumour Immunological Response in Melanoma.
Cancers (Basel). 2023 Jul 24;15(14):3748. doi:
10.3390/cancers15143748.
13.	Saito Y, Takahashi T, Hiramatsu K, Serada S, Fujimoto M, Ohkawara T, Sugase T, Nishigaki T,Tanaka K, Miyazaki Y, Makino T, Kurokawa Y,
Nakajima K, Yamasaki M, Ishii KJ, Eguchi H, DokiY, Naka T. Nano-particulate Toll-like Receptor 9Agonist Potentiates the Antitumor Activity of Anti-Glypican-1 Antibody. Anticancer Res. 2023 Jun;
43(6):2425-2432. doi: 10.21873/anticanres.16410.
14.	Toriyama M, Rizaldy D, Nakamura M, Atsumi Y,
Toriyama M, Fujita F, Okada F, Morita A, Itoh H,Ishii KJ. Dendritic cell proliferation by primarycilium in atopic dermatitis. Front Mol Biosci.
2023 Apr 26;10:1149828. doi: 10.3389/fmolb.2023.
1149828.
15.	Ito D, Ito H, Ando T, Sakai Y, Ideta T, Ishii KJ, Ishikawa T, Shimizu M. Spermidine enhances the efficacy of adjuvant in HBV vaccination in mice.
Hepatol Commun. 2023 Mar 24;7(4):e0104.
doi:10.1097/HC9.0000000000000104
16.	Yoshioka Y, Kobiyama K, Hayashi T, Onishi M,Yanagida Y, Nakagawa T, Hashimoto M, Nishinaka A, Hirose J, Asaoka Y, Tajiri M, Hayata A, Ishida S, Omoto S, Nagira M, Ishii KJ. A-910823, asqualene-based emulsion adjuvant, induces T follicular helper cells and humoral immune responses via α-tocopherol component. Front Immunol.
2023 Feb 20;14:1116238. doi: 10.3389/fimmu.2023.
1116238.
17.	Otsuka Saito K, Fujita F, Toriyama M, Utami RA,
Guo Z, Murakami M, Kato H, Suzuki Y, Okada F,Tominaga M, Ishii KJ. Roles of TRPM4 in immune
responses in keratinocytes and identification of anovel TRPM4-activating agent. Biochem Biophys
Res Commun. 2023 Apr 30;654:1-9. doi: 10.1016/
j.bbrc.2023.02.062
18.	Sun X, Hosomi K, Shimoyama A, Yoshii K, Lan H,Wang Y, Yamaura H, Nagatake T, Ishii KJ, Akira S,Kiyono H, Fukase K, Kunisawa J. TLR4 agonist activity of Alcaligenes lipid a utilizes MyD88 andTRIF signaling pathways for efficient antigen
presentation and T cell differentiation by dendritic
cells. Int Immunopharmacol. 2023 Apr;117:109852.

26
doi: 10.1016/j.intimp.2023.109852.
19.	Atsumi Y, Toriyama M, Kato H, Nakamura M,Morita A, Takaishi M, Saito K, Tanaka M, Okada F,Tominaga M, Ishii KJ, Fujita F. Anti-Inflammatory

Role of TRPV4 in Human Macrophages. Immunohorizons. 2023 Jan 1;7(1):81-96. doi: 10.4049/immunohorizons.2200100.