ImmunoTox Letter
Symposium
Gut microbiota and immune diseases

June,2018- A new perspective on immunotoxicology –Rie Yanagisawa (NIES), Naoki Shimojo (Chiba

The 25th Annual Meeting of the JapaneseUniversity), Akira Shibuya (University ofSociety of Immunotoxicology (JSIT2018)

Tsukuba), Kiyoshi Takeda (Osaka University)
Poster and discussion session

1. DateSeptember 18-19th, 2018

September 19
Oral session

2. Venue

International session

International Congress Center, 2-20-3 Takezono,

KhaledTsukuba, Ibaraki 305-0032, Japan.

Hossain(UniversityofRajshahi,Bangladesh), Myint Myint Nyein (University ofMedicine (1), Myanmar)

3. President

Special lecture

Keiko Nohara

B Paige Lawrence (University of Rochester,(National Institute for Environmental Studies,USA)NIES)“Developmentalexposure

alterscellularprocesses critical for T cell functions, and affects
4. Main theme of the meetingsome T cell properties across generations”

Discussing and deepening our insight into theLuncheon seminarinteraction between the immune system and theenvironment

Charles River Laboratories
Workshop“Development of cancer immunotherapy and5. Meeting Secretariat
Centerfor

Health and Environmental

safety assessment of immune checkpoint inhibitors
RiskResearch, NIES“Organizer: Shigeru Hisada (Aska Pharmaceutical)

Takehiro Suzuki (Secretary General)
E-mail: jsit25-office@nies.go.jp

Hiroshi Shiku (Mie University), Kazuhiko Taguchi(Bristol-Myers Squibb), Minoru Satoh (University

6. Program (tentative)of Occupational and Environmental Health)

September 18
Oral session

7. Social gathering

Luncheon seminar

September 18, 18:30-20:30

Covance

Hotel Grand Shinonome: www.hg-shinonome.co.jp/

Educational lecture
Akihiko Yoshimura (Keio University)“Immune regulation by epigenetic modificationsof T cells” (tentative)

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The 6th Japanese Society of Immunotoxicology Award(The 2016 JSIT Award)

Immunotoxic effects of agro-chemicals.
Tadashi Kosaka
Study Management Division, the Institute of Environmental Toxicology
It is well known that agro-chemicals have a potential to cause the toxic effects onimmunological functions. Then, we investigated the potential adverse effects of pesticides,organochlorine pesticide methoxychlor and organophosphorus pesticide parathion, onimmune-suppression.
First, induction of apoptotic changes of the T cells treated with pesticides was investigated in
the in-vitro and in-vivo studies. In order to detect the ability to induce the apoptosis of T cells,
pesticides were incubated with mouse T cells and Jurkat cells in the RPMI 1640 medium
containing 10% fetal calf serum. In this study, both of methoxychlor and parathion could
cause apoptotic changes in both of mouse T cells and Jurkat cells.

In-vivo study, TUNEL

positive cells and/or AnexinV positive cells, which are indicative of apoptosis, were detected inrat pups in Utero pesticide exposure and in immature mice treated with repeated dosing ofmethoxychlor.
Secondly, to assess the immunosuppressive response to repeated exposure to some pesticides,
ICR，Balb/c and C3H/He strain mice were treated with methoxychlor at 0, 150, 50, 1500 ppm infeed for 4 weeks.

All mice were immunized with SRBC (Sheep red blood cell) byintraperitoneal injection (6 x 107/mice) 4 days before sacrifice, and their SRBC-IgM responses
were subsequently assessed using ELISA method and PFC (Plaque-forming cell) assay.
Repeated dosing with methoxychlor induced marked decreases in the production of
SRBC-specific IgM antibodies in Balb/c and C3H/He mice.
Third, we examined the relationship between dermal allergy and the immunosuppression
induced by immunosuppressive pesticides.

1) The modulating potential of theorganophosphorus pesticide (immunosuppressive chemicals) were studied for the skinsensitization of a contact allergen (phenoxyacetic acid herbicide; 2,4-d-butyl) using a local
lymph node assay (LLNA). Four-week-old mice were orally administered parathion (0, 0.4,1.2mg/kg) or methoxychlor (0, 100, 300 mg/kg). Four weeks after the last administration, anLLNA was conducted using 2,4-d-butyl. EC3 values of 2,4-d-butyl decreased markedly inparathion- and methoxychlor-pretreated groups.

2) The effects of the immunosuppressive

pesticides on TNCB-induced atopic dermatitis (AD) were investigated in NC/Nga mice. Mice
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ImmunoTox Letter

were orally exposed to these chemicals (age, 4 weeks) and 4 weeks later received sensitizationand challenge dosing (age, 8–12 weeks) with TNCB. Exposure to parathion and methoxychlor,immunosuppressive pesticides, markedly increased dermatitis severity including ear thickness
and scored skin irritation. From there results, immunosuppressive pesticides can influence on
the aggravation for the sensitizing response of some chemicals in LLNA assay or allergic
responses in an atopic dermatitis model induced by TNCB.
Forth, male and female rat pups were obtained from dams receiving methoxychlor at dietarylevels of 0, 30, 100, 300, and 1,000 ppm during the gestation and lactation period. They werefed a normal diet after weaning and kept up to 52 weeks of age.

At 52 weeks of age, chronic

nephropathy having enlarged glomeruli with increased IgM deposits in females at 1,000 ppm
treatment group.
Thus, our investigation can exhibited the potential adverse effects of the pesticide on immune
mechanisms that can lead to harmful changes in host responses such as; increased susceptibility
to infectious diseases; the induction of hypersensitivity reactions; or an increased incidence ofautoimmune disease. And, it is concluded that our short-term exposure protocol may be usefulfor detecting environmental chemicals having immunosuppressive potential.

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The 7th Japanese Society of Immunotoxicology Award(The 2017 JSIT Award)

Differential immunologic alteration in a mouse model
exposed to low levels of volatile organic compounds
Hidekazu Fujimaki
National Institute for Environmental Studies
An increasing trend in the prevalence of allergic diseases, including asthma, rhinitis andeczema, has been reported from many industrialized countries. Toxic air pollutants such asvolatile organic compounds (VOCs) can occur at relatively high concentrations in homes andbuildings. The studies of unexplained symptoms observed in chemically sensitive subjects
have been increased. However, there have been no studies on the effects of low-level
inhalation of VOCs on the modulation of allergic and neurogenic inflammation in relation tothe indoor air quality.
(1) Short-term formaldehyde (FA) exposure may directly produce dysfunction andinflammation in airways and aggravate allergic inflammatory reactions. However, nothing is
yet known about the long-term effects of low-level FA exposure on allergic inflammation. We
exposed C3H mice to low levels of FA and measured immunological parameters. Our results
indicate that low levels of FA did not induce serious respiratory allergic inflammation, but
modulated the production of nerve growth factor (NGF) in mice.
(2) The effect of low-level exposure to toluene on the airway inflammation in mice wasstudied and showed that toluene exposure aggravated the airway inflammatory responses inovalbumin-immunized mice. Moreover, low-level exposure of immunized mice to toluene canmodulate NGF signaling pathways in allergic airway inflammation and may disturb
neuroimmune crosstalk between neurotrophins and allergic inflammation processes. The
expression of neurotrophins and their receptors in adult mouse hippocampus was up-regulatedby the exposure to low levels of toluene in a strain-dependent manner.
(3) The developing immune system may be more sensitive to toxicant-induced alterations thanthat of adults. We investigated the window of susceptibility to toluene exposure on
immunological biomarkers during different developmental stages in infant mice and indicatedthat the late postnatal period which corresponds with neonatal period in human might
represent a window of greatest susceptibility to toluene exposure, eliciting developmental
toxicity. Dose-specific changes in neuroimmune markes in infant mice were also observed
following toluene exposure.
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The 7th Japanese Society ofImmunotoxicology Prize for Encouragement

Long-term topical glucocorticoids induce pruritus in a mouse modelof chronic dermatitis by affecting skin immunity.
Katsunori Yamaura
Faculty of Pharmacy, Keio University
It is my infinite honor and great pleasure to win the JSIT encouragement prize. I would liketo express my sincere thanks and gratitude to all of the members of the awarding committee.
Topical glucocorticoids are commonly applied for treatment of chronic, inflammatory,
pruritic skin disease such as atopic dermatitis, and are often administered over a long period. I
reported that long-term topical dexamethasone exacerbates pruritus in a mouse model of allergic
contact dermatitis (ACD). BALB/c mice with ACD induced by 5 weeks of repeated applicationof 2,4,6-trinitro-1-chlorobenzene (TNCB) were treated topically with dexamethasone for 3
weeks from 2 weeks after the elicitation of dermatitis. Significant enhancement of pruritus wasconfirmed after chronic application of dexamethasone. This increased frequency of scratching
behavior was reduced by withdrawal of dexamethasone. On the other hand, ear-swelling wasmarkedly ameliorated by dexamethasone treatment, but rapidly relapsed after dexamethasone
withdrawal. I investigated the cause of augmentation of pruritus with a focus on the productionof prostaglandin (PG) D2. The scratching behavior induced by TNCB was augmented by topicalapplication of dexamethasone, but dexamethasone did not have any effect on scratching bouts inmice that had not been treated with TNCB. Topical dexamethasone reduced the PGD 2 level,
which increase in TNCB-treated mice, to the baseline level. Moreover, dexamethasone
significantly decreased the PGD2 production in IgE/antigen-stimulated RBL-2H3 mast cells;
however, the same concentration of dexamethasone did not have any effect on the degranulationof stimulated mast cells. I concluded that topical glucocorticoids may exacerbate pruritus in amouse model of ACD via inhibition of PGD2 production in antigen-mediated activated mastcells in the skin. Furthermore, I elucidated the involvement of PGD2 and its receptor (DP1) inaugmentation of pruritus induced by dexamethasone, prednisolone, or betamethasone valerate.
Finally, I would like to express my deepest appreciation to Prof. K. Ueno, Dr. H. Satoh, Dr.
RL. Thurmond and my students for their encouragement, support, comments, and suggestions.

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