UNRAVELINGTHE SECRETS
OF IMMUNOLOGY

WWW.M.CHIBA-U.AC.JPImpact Objectives• Basic research on immunological memory• Translational research on allergic and chronic airway inflammation• Development of immunotherapy for cancer• Development of guidance to ‘cultivate professional researchers’

Keen collaborator
Professor Toshinori Nakayama has been working to improve the collaborative and teaching efforts of
the Department of Immunology at Chiba University in order to tackle key questions in immunology

Can you share a little about how yourown career has developed? Have there
been any key moments that have changed
the pathway?
There are two people who have influenced
my life the most: Dr Tomio Tada, my PhD
advisor in the Graduate School of Medicine
at the University of Tokyo; and Dr AlfredSinger, my supervisor at the National
Institutes of Health. As a student, I was
awe-struck by Dr Tada’s presentations andfascinated by the world of immunology. I
decided to enter Dr Tada’s lab right after
graduating from medical school. Immune
system research was still unknown territory
at the time (early 1980s). I found it thrillingand challenging to discover new processes
and to expand the field. Dr Tada taught mea wide range of knowledge and skills: fromthe joy of science to the pleasure of new
cultural discoveries. Dr Singer taught me
how to promote research and how to delivera successful presentation: even an academicpresentation should be entertaining!
In what ways are international
collaborations important to the projects you
are involved with?
The most important thing aboutcollaboration is conducting a thoroughstudy to see the whole picture of a problem.
In that sense, it does not matter if thecollaboration is domestic or international.
However, Japanese research andtechnology is sometimes criticised for its
inward-looking tendencies. International
collaborations provide us with different
perspectives and opportunities to develop
networks, and also help us to maintainglobal standards and prevent the pursuit ofGalapagos technologies and domesticallyfocused research.
You have a number of joint research projects
underway. How important is the relationshipwith other academic institutions as well as
healthcare organisations to this research?
Through collaborations we can shareresources such as genetically modified
mice and then each researcher can study
the event from his/her own standpoint.
For example, a pharmacologist can provide
materials by creating one chemical orreagent and then researchers can test its
effect using a knockout mouse or mousemodel of a certain disease. Based on the
animal study, we can conduct a clinicalstudy in collaboration with researchers fromclinical departments. By doing so, we canmaximise the specialty of each researcher.
How does the Japanese Global Centers of
Excellence (COE) Program support andcultivate professional researchers withinyour Department?
In Japan, the scholarship system forgraduate students remains unsatisfactory. I
believe the Global COE Program has helped
students concentrate on their research. In
Global COE, we use various measures toencourage our students to be professional

researchers. These include providing extra
opportunities including workshops or study
abroad so that students can collaborate
with overseas researchers; establishingan annual prize for the best student toinspire a deeper commitment to research;and providing broad educational andresearch support from basic science toclinical research.
Can you talk a little about what theInternational Immunological Memory and
Vaccine Forum (IIMVF) meeting is and its
importance to your work?
We hold the IIMVF meeting once a year
in order to promote three key areas:
1) information exchange and mutual
professional and social friendship among
junior researchers, and between juniorand senior researchers; 2) disseminationof junior researchers’ studies to the worldcommunity by making presentations anddiscussions in the presence of world-classresearch leaders; and 3) industry-academia
joint research at the international level, andprocurement of research funds.
What do you foresee your Department’s
research themes will be going forward?
One of my goals is to clarify pathogenesisof intractable chronic inflammatory diseaseat the molecular, genetic and cellular levelin order to develop a novel treatment. We
can then apply our findings to research inmany fields including autoimmune disease,allergy, tumour immunology and cancer.

Breathe easy
Through her work in the Department of Immunology at Chiba University, Dr Motoko Y Kimura hopes
to offer relief to sufferers of refractory allergic diseases
found that CD69 antibody treatment
efficiently ameliorates allergic responses
in mouse models, and that it is due tofailure of recruitment of CD69 expressing
inflammatory cells into lung tissues. We are
currently working on the mechanisms how
CD69 antibody works, and getting to know
the existence of functional CD69 ligands ininflamed lung.

What drives you to continue your research
into immunology?
I love Mother Nature and living creatures
and am curious how creatures develop andcontinue to live; these curiosities drove
me to become a scientist. As immunology
is one of the well-organised systems thatare essential for life, I chose this area andhave been studying T lymphocytes, which
are crucial for acquired immunity. I would
like to engage in research on fundamental
life phenomena. I would feel enormous
pleasure if a discovery of mine is applied tothe treatment of patients who are sufferingfrom refractory diseases in the future.
Can you talk about the CD69 antibody
project you are currently involved in?
I am looking at the role of CD69 on
immune cell development and on immune
responses. CD69 has been identified as
an early activation marker; however, it
was not really known if there were any
biological roles of its expression except
for its regulation of S1P1 expression. Due
to our extended efforts, we now know that
CD69 is not a simple activation marker
and actually has a crucial role in immune
responses, especially inflammation. We

How did the idea for your research on CD69
antibody treatment for refractory allergic
diseases come about?
Our lab has been working on CD69 biology
for a long time. In the early 1990s, CD69
was known as a simple early activation
marker on leucocytes such as T cells,
but was not thought to have crucial
functions for immune responses. WhenI was doing my Master’s, I had a chance
to analyse CD69 knockout mice that ourlab had made for the first time in theworld. At that time, we thought that CD69
should have some roles on thymocyte
development since CD69 expression is
specifically upregulated during thymocyte
development. Unfortunately, we couldn’t
find any significance in the thymus at thattime, but eventually we found that CD69
expression on activated leukocytes is crucial
for inflammation in the periphery. I was very
excited to be involved in these discoveries.
What are your views on the current situation
around gender equality in science?
Considering the fact that female faculty
members make up less than 10 per centof Chiba University’s Medical School, I
consider myself fortunate to be a faculty
member and to have the opportunity toproceed with my science. I know manysmart and dedicated female PhD students
who quit science before becoming a faculty
member. I think it is due to the conservative
society pressures on women to take careof the household and to raise children andso on which makes it difficult for women
to continue to work. On the other hand,female scientists can benefit from beinga minority, since academic societies aretrying to have more female scientists andare giving more opportunities to them. I
hope more female students decide to workin academia because I think women can be
excellent scientists!
How are you supporting graduate students
and young researchers in the Department of
Immunology through your research?
I think deep discussion of the data is mostimportant, not only to advance each project,
but also to educate students in how to be
an independent scientist. I try to create
an environment where all students canfreely talk their thoughts and ideas. Eachstudent has his/her own unique character;therefore I try to get to know each student
well so that we develop good relationships
and communicate well. This is a necessary
step to enable deep discussion. I enjoy
discussing data with my students andlearning many things from them too.

Controlling inflammation
By analysing the involvement of Th2 cells in chronic inflammatory diseases, Associate Professor Kiyoshi
Hirahara of the Department of Immunology at Chiba University is aiming to develop new treatmentsfor pulmonary fibrosis
Do you think there any key questions
about immunity that need addressing?

How has your career in basic medical
research developed?
After obtaining my medical doctor’s licencein Japan, I was engaged in clinical practiceas a physician, specifically in respiratory
medicine, for more than five years. Duringthat time, I saw many cases that current
treatments could not cure and keenly felt
the desperate need for new treatments.
Aware of the importance of basic research,I decided to become a basic medical
researcher. This led me to explore immune
responses in the respiratory apparatus(upper and lower respiratory tract) andintractable respiratory diseases, including
pulmonary fibrosis. I have conductedvarious research activities focusing on CD4+
T cells throughout my graduate studies
under the instruction of Professor Toshinori
Nakayama at Chiba University and postdoc
under Dr John J O’Shea at the Molecular
Immunology and Inflammation Branchof the US National Institute of Arthritis
and Musculoskeletal and Skin Diseases.
Currently I am carrying out research mainlyon the identification of the roles of CD4+ T
cells in intractable respiratory diseases.

Currently, it is considered that
abnormality of the immune system
might be contributing to pathologicalprocess of various intractable diseases.
Therefore, medical agents with a variety of
immunosuppressive properties, such as
steroids, are used in treating these diseases.
However, these types of treatments canonly cure a limited number of cases. Thismeans that the development of a novel
therapy by elucidation of pathologicalconditions involving the immune system isa pressing task.
What topics are you currently investigating?
Pulmonary fibrosis is a disease in which
the alveolar epithelium – responsible forgas exchange in the lungs – becomes
harder and harder due to chronic
inflammation of the lungs from various
causes. As pulmonary fibrosis worsens, it
progressively leads to respiratory failure.
Above all, idiopathic pulmonary fibrosis isan extremely poor-prognosis disease and
50 to 70 per cent of patients die within five
years of diagnosis. Over 10,000 patientsare currently suffering from idiopathic
pulmonary fibrosis in Japan and there isno curative treatment for the disease. It
has substantial resistance to existing drugs
including steroids, and its mechanism inpathological conditions remains unknown.
As such, I am undertaking research focusing
on the fibrosis of the lung tissue with a goalof pathological clarification of the disease.

In what ways will the functional analysis
of pathogenic Th2 cells impact on thehealthcare sector?
Currently, most of the major
immunosuppressive agents used in theworld have low specificity and are classified
either as drugs with limited therapeutic
effects or as drugs with curative properties
and strong side effects. It is my belief
that research on pathogenic Th2 cells will
result in a more specific drug target ornovel biomarker.
How valuable is the strength of the
Department of Immunology’s existing
collaborations for achieving the outcomesfrom your research?
We are currently conducting a joint
research project with Professor Yoshitaka
Okamoto from the Department ofOtorhinolaryngology‚ Head and Neck
Surgery here at Chiba University. Under thisstudy, we are translating the concept, which
we created based on the outcomes from ourmouse study, into humans. We use samplesof patients with various types of diseases
to analyse how tissue fibrosis becomes
advanced at local inflamed sites in humans.
This joint research is making great progress
and giving an additional boost to our study
on pathological clarification of various
diseases. We are committed to producing
concrete results every day.

Unraveling thesecrets of immunology
Researchers in the Department of Immunology at Chiba University are using an expanded network ofcollaborators to further understand the role of Tpath2 cells in chronic inflammation

I

mmunology is an extremely complex
subject. The interactions between thethousands of cell types within the two
immune systems – innate and adaptive –allow for huge flexibility in tackling foreign
invaders and domestic pathogens such as
cancer. Given the complexity of the system, it
is not surprising that mistakes arise.
Such mistakes range from the hugely
destructive responses to certain pathogens
through allergic reactions to an inability
to recognise cancerous cells. The cell
types involved in these processes often
have multiple functions, regularly altering
themselves to meet different functional
requirements. Type 2 helper cells (Th2cells) are one such cell type. Most of
the Th2 cells detected in our peripheral
blood are immunological memory cells
that are stimulated when the body is
exposed to the same antigens that it has
previously encountered. These can befrom microorganisms and viruses, but canequally be from allergens. This means that
pathogenic forms of these cells (Tpath2
cells) are often responsible for chronic
inflammatory responses where epithelia react
recurrently to a long-past antigen. Professor
Toshinori Nakayama of the Department of
Immunology at Chiba University has directed

Graduate Student sitting at the clean bench to adjust thereagent and to determine quantity of Cytokine-producing
cells

his research to discovering the causes of, andfinding solutions to, chronic inflammation.
Nakayama and his team were the firstto identify Tpath2 cells and have recently
discovered their key role in chronic
inflammation. The researchers take anall-encompassing approach, looking at
the issue from several different biologicalangles. These include investigating themolecular changes occurring in Th2 cells as
they become pathogenic, the location andeffects of these cells in mice models, andidentifying their location in patient samples.
This approach allows Nakayama to focus on
his ultimate aim: ‘The results of our work willbe the evidence required to develop a newtreatment or vaccine utilising immunologicalmemory. My hope is that our research will
result in a vaccine with which you can never
get a disease and which has no major side
effects.’ In order to further these aspirations,Nakayama has also set up a growing networkof international collaborations and has
steered the focus of the department to aiding
young researchers.
THE PATH TO A VACCINE
The story of pathogenic Th2 cells begins witha desire to know the causes of chronic lunginflammation in some asthma sufferers.
A key cause of asthmatic inflammation isa group of cells called eosinophils that arenormally responsible for tackling parasite
infection. Eosinophils are activated by thepresence of interleukin 5 (IL-5), a soluble
protein called cytokine. Nakayama and his
team identified a subpopulation of Tpath2
cells that produce abundant IL-5, stimulating
eosinophils and creating the allergic
response. Additionally, they found Tpath2
cells persisted and therefore led to chronic
inflammation in the region where the cells

Main Building of the Faculty of Medicine built in 1936

were present. This is a particular problem
because, unlike regular asthma, chronic
asthma can’t be treated with steroids.
However, these discoveries left manyquestions unanswered. Chief amongst thesewere how Th2 cells were activated and how
they maintained this activation state.
After extensive investigation, Nakayama
and his team discovered that Tpath2 cells
were stimulated to produce IL-5 by anothercytokine – IL-33. This second cytokine isreleased by epithelial cells (in the lungfor asthma) and causes a change in theorganisation of the DNA containing thegene for IL-5. The structural change in the
DNA causes IL-5 to be highly expressed in
Tpath2 cells. This explains how the cells
are activated to recruit eosinophils in thefirst place; however IL-33 signalling by theepithelial cells is not constant and therefore
this did not explain the chronic aspect of theinflammation. Further work in mouse models
and using human samples helped uncover
the chronicity of the pathology. The teamdiscovered that a combination of two otherinterleukins, IL-2 and IL-25, was capable ofproducing the same DNA remodelling as IL33. Additionally, these two proteins are bothproduced by the same eosinophils previously
activated by Tpath2 cells. It is therefore easy
to see that an exacerbating cycle is created

The results of our work will be the evidence required to develop a new treatment or
vaccine utilising immunological memory. My hope is that our research will result in a
vaccine with which you can never get a disease and which has no major side effects
by the two cell types leading to chronic
inflammation at the site of this interaction.
These foundational findings are an essential
step to finding a way to treat chronic
inflammation. Nakayama is continuallyworking closely with clinicians in orderto develop means through which thisknowledge can be applied to patients.
Additionally, he and his team are pursuingseveral other research angles which showpromise of finding a solution. Nakayama andthe Department of Immunology are clearly
seeing the research benefits of increased
national and international collaboration,with a regular stream of thorough scientificinvestigation into chronic inflammation andother immunological issues.

International collaborations
The sharing of discoveries and expertise is essential to all good scientific research. Japan
has often stood accused of focusing too heavily on research and technology aimed solely
at tackling domestic issues. This insular approach is one many researchers are keen to
shed. Led by Professor Nakayama, the Department of Immunology at Chiba University
is attempting to reverse this impression. In order to do so, Nakayama has initiatedseveral programmes and collaborations aimed at engaging the international communityand drawing in foreign researchers to work in the department. He is taking four key andinterlinked approaches to tackling the issue.
The Japanese Global Centers of Excellence (COE) Program was a national programme
designed to increase international competitiveness. Most of the departments in Chiba
University’s Graduate School of Medicine, including the Department of Immunology,
benefited directly from this funding by being able to advance and expand their research.
Particularly, there was a focus on making funds available to develop young talent.
Traditionally, funding for students has been tough in Japan, as Nakayama explains: ‘The
scholarship system for graduate students remains unsatisfactory. It is common thatstudents or their parents pay for tuition and living expenses. Global COE enabled us to pay
US$1,000 per month to about 50 students every year, additionally, the programme allowed
the recruitment of talented foreign researchers who helped to provide new perspectives
to the Department’s work. Another important aspect to the student development process
is the Leading Graduate School (LGS). The LGS aims to create international leaders
who will contribute significantly to research in immune-related diseases as well as tothe development of new drugs and methods of treatment. This is achieved throughproviding students with a multidisciplinary approach to their learning and offering extra
funding opportunities.
In order to further the aim of increasing international involvement in immunologicalresearch, Nakayama has instigated two essential initiatives. Firstly, the university has
recently announced a new joint partnership with the University of California, San Diego. A
joint Research Centre has been designed to create preventative vaccines against a range
of infectious diseases, allergies and cancers. Included in this remit is a focus on academic
exchanges – giving young researchers a chance to experience a different, yet still highquality, research experience. Additionally, exchanges of senior staff allow a closer sharing ofideas and direction between these two world-leading institutions, as Nakayama explains:‘Through these efforts, I believe we can foster international-standard researchers who can
produce cutting-edge findings.’ Secondly, Nakayama is heavily involved in the International
Immunological Memory and Vaccine Forum (IIMVF). The IIMVF is an annual conferencewith a focus on young researchers’ work. The conference aims specifically to help
information exchange between all involved; to promote friendships between researchers
at all levels; to highlight the work of early-stage scientists; and to facilitate the expansionof industry-academia partnerships. Chiba University will host the next iteration of theconference in 2017.

Project Insights
TOPICS OF CURRENTRESEARCH PROJECTS• Generation and maintenance of
immune system• Clarification of mechanism of allergy
onset and therapeutic development
CONTACT
Toshinori Nakayama
Professor and Chairman
Department of Immunology
Graduate School of Medicine
Chiba University
T: +81 43 2262185
E: tnakayama@faculty.chiba-u.jp
W: http://www.m.chiba-u.ac.jp/class/meneki/english/index.html
PROJECT COORDINATOR BIO
Professor Toshinori Nakayama leads
the Department of Immunology in
the Graduate School of Medicine at
Chiba University, Japan. After studying
the field of immunology for many
years he is now focused on basic
research into immunological memory
and translational research on allergy
and cancer. Nakayama has written anumber of published papers on these
topics. He has also received a numberof awards recognising his work inthis field, including the 3rd JapaneseSociety for Immunology Award in 2000
and the 14th Abbott Japan Allergy
Research Award in 2004. Nakayama
is member of a number of societies
including the American Association of
Immunologists, the American Society
for Biochemistry and Molecular Biology
and the Molecular Biology Societyof Japan.