POS0794 PREGNANCY AND CHILDBIRTH IN TAKAYASU ARTERITIS IN JAPAN – A NATIONWIDE RETROSPECTIVE STUDY

Background

Takayasu arteritis (TAK), a granulomatous large vessel vasculitis, mainly involves the aorta and its proximal branches and commonly occurs in young females. However, studies of pregnancy in women with TAK are sparse and limited, probably due to the rarity of the disease.

Objectives

The purpose of this study was to understand the status quo of medical treatments of the primary disease and outcomes of pregnancy in patients with TAK, and birth outcomes of the children in Japan.

Methods

Patients with TAK who conceived after the onset of the disease and were managed at medical facilities participating in the Japan Research Committee of the Ministry of Health, Labour, and Welfare for Intractable Vasculitis (JPVAS) were retrospectively enrolled in this study. The following information was collected from patients who had a live-born baby: age at diagnosis of TAK, disease classification, age at delivery, treatments before and during pregnancy, complications during pregnancy, birth outcomes of the children, and changes in disease activity during pregnancy and after delivery.

Results

Fifty-one cases and 69 pregnancies from 19 ethics committee-approved centers were enrolled during the study period 2019–2021. Of these, 49 cases and 66 pregnancies (95.7%) resulted in delivery and live-born babies. The Numano classification of the 49 cases was as follows: type I, 11; type IIa, 15; type IIb,12; type III, 1; type IV, 1; type V, 9; with type IIa being the most common. The age of diagnosis was 22 years (13–37 years, year of diagnosis 1965–2017), the median age of the delivery of 66 pregnancies was 31 years (year of delivery 1969-2021), and the median duration of illness at delivery was nine years. There were 34 planned pregnancies (51.5%, including four pregnancies by artificial insemination/ovulation induction). Preconception therapy included prednisolone (PSL) in 51 pregnancies (77.3%, median dose 7.5 mg (range 4–30 mg)/day), immunosuppressive drugs in 18 pregnancies (27.3%, azathioprine 8, tacrolimus 7, methotrexate 4, cyclosporin A 1, and colchicine 1), biologics in 12 pregnancies (18.1%, infliximab 6, tocilizumab 5, and adalimumab 1), antihypertensive drugs in 5 pregnancies (7.6%). Surgical treatment had been performed before pregnancy in 6 cases (aortic root replacement 2, subclavian artery dilatation 1, subclavian artery bypass 1, subclavian artery stenting 1, and ascending aorta semicircular artery replacement 1). Medications used during the course of pregnancy included PSL in 48 pregnancies (72.7%, median dose 8 mg (range 4–30 mg)/day, increased in 13 pregnancies, decreased in 1 pregnancy), immunosuppressants in 13 pregnancies (19.7%, azathioprine 6, tacrolimus 6, and cyclosporin A 1), biologics 9 pregnancies (13.6%, infliximab 4, tocilizumab 4, and adalimumab 1). Immunosuppressants and biologics were discontinued in five and four pregnancies after conception. Complications during pregnancy were observed in 20 pregnancies (30.3%), with hypertension being the most common. Complications related to TAK or its treatment were severe infections in two pregnancies and aneurysm enlargement due to increased circulating plasma volume in one pregnancy. Aortic arch replacement was performed after delivery for the latter case. Relapse of TAK was observed in 4 pregnancies (6.1%) during pregnancy and in 8 pregnancies (12.1%) after delivery. One pregnancy resulted in restenosis of subclavian artery for which dilatation procedure was performed prior to the pregnancy. There were 13/66 (19.7%) preterm infants and 17/59 (28.8%) low birth weight infants; all but one had a birth weight of more than 2,000 g and no had serious postnatal abnormalities. Forty-three (82.7%) of the 52 confirmed infants were breastfeed fully or mixed.

Conclusion

Most of the pregnancies in patients with TAK were successfully delivered while they had low disease activity at a dose of less than 10 mg/day of PSL. Relapse occurred during pregnancy and after delivery in some cases. The babies tended to have low birth weight, but 82.7% of them were breastfed without serious complications.

Disclosure of Interests

Takako Miyamae: None declared, Yusuke Manabe: None declared, takahiko sugihara Speakers bureau: TS has received honoraria from Abbvie Japan Co., Ltd., AsahiKASEI Co., Ltd., Astellas Pharma Inc., Ayumi Pharmaceutical, Bristol Myers Squibb K.K., Chugai Pharmaceutical Co., Ltd., Eli Lilly Japan K.K., Mitsubishi-Tanabe Pharma Co., Ono Pharmaceutical, Pfizer Japan Inc., Takeda Pharmaceutical Co. Ltd., and UCB Japan Co., Grant/research support from: TS has received research grants from AsahiKASEI Co., Ltd., Daiichi Sankyo., Chugai Pharmaceutical Co., Ltd., and Ono Pharmaceutical., Natsuka Umezawa: None declared, Hajime Yoshifuji Speakers bureau: HY has received lecture fees from Janssen and Chugai., Naoto Tamura: None declared, Yoshiyuki Abe: None declared, Shunsuke Furuta Speakers bureau: Chugai Pharmaceutical Co.,Ltd.

DaiichiSankyo Co.,Ltd.

Asahi-Kasei Pharma Corporation, Manami Kato: None declared, Takashi Kumagai: None declared, Kaito Nakamura: None declared, Hiroko Nagafuchi: None declared, Jun Ishizaki: None declared, Naoko Nakano: None declared, Tatsuya Atsumi Speakers bureau: Mitsubishi Tanabe Pharma Co., Chugai Pharmaceutical Co., Ltd., Astellas Pharma Inc., Takeda Pharmaceutical Co., Ltd., Pfizer Inc., AbbVie Inc., Eisai Co. Ltd., Daiichi Sankyo Co., Ltd., Bristol-Myers Squibb Co., UCB Japan Co. Ltd., Eli Lilly Japan K.K., Novartis Pharma K.K., Eli Lilly Japan K.K., Kyowa Kirin Co., Ltd.,TAIHO PHARMACEUTICAL CO., LTD., Consultant of: AstraZeneca plc., MEDICAL & BIOLOGICAL LABORATORIES CO., LTD., Pfizer Inc., AbbVie Inc., ONO PHARMACEUTICAL CO. LTD.,

Novartis Pharma K.K., Nippon Boehringer Ingelheim Co., Ltd., Grant/research support from: Astellas Pharma Inc., TAIHO PHARMACEUTICAL CO., LTD.AbbVie Inc., Nippon Boehringer Ingelheim Co., Ltd.,Takeda Pharmaceutical Co., Ltd., Mitsubishi Tanabe Pharma Co., Chugai Pharmaceutical Co., Ltd., Daiichi Sankyo Co. Ltd., Otsuka Pharmaceutical Co., Ltd. and Pfizer Inc. Alexion Inc., TEIJIN PHARMA LIMITED., Kohei Karino: None declared, Koichi Amano Speakers bureau: AbbVie GK, Asahi-Kasei Pharma, Astellas, Chugai Pharmaceutical Co.Ltd., Eisai, Eli Lilly, GlaxoSmithKlein, Janssen Pharma, Pfizer Japan, Grant/research support from: Asahi-Kasei Pharma,Chugai Pharmaceutical Co.Ltd., Takahiko Kurasawa: None declared, Shuichi Ito: None declared, Ryusuke Yoshimi: None declared, Noriyoshi Ogawa: None declared, Shogo Banno: None declared, Taio Naniwa Speakers bureau: Chugai, Tanabe, Abbbvie, Eisai, Grant/research support from: Chugai, Tanabe, Abbbvie, Eisai, Satoshi Ito Speakers bureau: SI has received speaker’s fees from pharmaceutical companies., Akinori Hara: None declared, Shinya Hirahara: None declared, Haruhito A. Uchida: None declared, Yasuhiro Onishi: None declared, Yohko Murakawa Speakers bureau: Astellas, UCB, Chugai, AbbVie, Grant/research support from: Chugai, AbbVie, Yoshinori Komagata: None declared, Yoshikazu Nakaoka: None declared, Masayoshi Harigai Speakers bureau: MH has received speaker’s fee from AbbVie Japan GK, Ayumi Pharmaceutical Co., Boehringer Ingelheim Japan, Inc., Chugai Pharmaceutical Co., Ltd., Eisai Co., Ltd., Janssen Pharmaceutical K.K., Kissei Pharmaceutical Co., Ltd., Novartis Japan, Pfizer Japan Inc., Mitsubishi Tanabe Pharma Co., Teijin Pharma Ltd and UCB Japan., Consultant of: MH is a consultant for AbbVie, Boehringer-Ingelheim, Kissei Pharmaceutical Co., Ltd., and Teijin Pharma.

POS0336 PATTERNS OF LARGE-VESSEL LESIONS AND POOR TREATMENT OUTCOMES IN PATIENTS WITH LARGE-VESSEL GIANT CELL ARTERITIS

Background:

Giant cell arteritis (GCA) is characterized by cranial symptoms and large-vessel lesions (LVL) in the aorta or its branches. We retrospectively analyzed the Japanese patients newly diagnosed as GCA between 2007 and 2014, and subsequently treated with glucocorticoid (GC). The imaging studies revealed that LVLs were observed in approximately half of the GCA patients, and the LVLs were significantly associated with the increased probability of poor treatment outcomes (1).

Objectives:

The objective of this study is to evaluate whether the distribution of LVLs of GCA was associated with poor treatment response.

Methods:

In a retrospective, multi-centric, nationwide registry of GCA patients treated with GCs between 2007 and 2014, 68 newly-diagnosed GCA with LVLs by imaging were detected. All investigators were members of Japan Research Committee of the Ministry of Health, Labour, and Welfare for Intractable Vasculitis (JPVAS). Poor treatment outcomes (non-achievement of clinical remission by week 24 or relapse during 104 weeks) were primarily evaluated. Cumulative rates and median time to the first event were analyzed by the Kaplan-Meier method and the log-rank test. Associated factors with the outcomes were analyzed by using the Cox proportional hazard model.

Results:

The mean age was 70.5 years, and 70.6% were women. Twenty-seven (39.7%) of the 68 patients were diagnosed as having GCA by both positive temporal artery biopsy and positive imaging, and 41 (60.3%) by positive imaging. Aortic lesions were detected in 72.1% (group 2, n=49) of the 68 GCA patients with LVLs. Patients without aortic lesions were categorized into two phenotypes: large-vessel GCA with subclavian lesions (group 1, n=9) and atypical large-vessel GCA without subclavian lesions (group 3, n=10). Cranial lesions were observed in 66.7%, 55.1%, and 80.0% in the group 1, 2, and 3, respectively. The initial mean dose (SD) of prednisolone was 0.74 (0.26) mg/kg/day, and 20.6 % received methotrexate for remission induction therapy. Baseline dose of GCs and mean time to achievement of low-dose GCs (prednisolone ≤ 5 mg/day) was not significantly different among the three groups.

Overall, 35 (51.5%) of the 68 patients had the event of poor treatment outcomes. Eleven patients were not able to achieve clinical remission by week 24. Relapse after achievement of clinical remission was reported in total of 24 patients; 9 between week 0 and 24, 12 between week 24 and 52, 3 between week 52 and 104. The cumulative rate of events of poor treatment outcomes over the two years was 11.1% in patients with group 1, 55.3% in those with group 2, and 88.0% in those with group 3. Mean time to events was significantly different among the three groups. Multivariable analysis showed the risk of poor treatment outcomes was likely to decrease in the group 1 (hazard ratio 0.14 [95% CI 0.02-1.03], p=0.054), while it increased in the group 3 (hazard ratio 2.22 [95% CI 1.06-4.68], p=0.035).

Conclusion:

The distribution of LVLs were associated with poorer treatment outcomes. A half of the patients with aortic lesions had poor treatment outcomes while subclavian arteritis without aortic lesions had better clinical outcomes. Atypical large vessel-GCA without the aortic and subclavian artery involvement was the worst prognostic phenotype of LV-GCA. Extent of LVLs by imaging should be considered when determining the treatment strategy for GCA.

References:

[1]Sugihara T, et al. Arthritis Res Ther. 2020;22(1):72

Acknowledgements:

The authors would like to acknowledge Mitsuaki Isobe (Sakakibara Heart Institute), Yoshihiro Arimura (Kichijoji Asahi Hospital), and all the investigators in the Japan Research Committee of the Ministry of Health, Labour, and Welfare for Intractable Vasculitis (JPVAS). In addition to the authors, the following investigators and institutions participated in this study: Department of Internal Medicine, Juntendo University Koshigaya Hospital (Shigeto Kobayashi); Niigata Rheumatic Center (Satoshi Ito); Niigata Prefectural Shibata Hospital (Noriyuki Homma).

Disclosure of Interests:

takahiko sugihara Speakers bureau: TS has received honoraria from Abbvie Japan Co., Ltd., AsahiKASEI Co., Ltd., Astellas Pharma Inc., Ayumi Pharmaceutical, Bristol Myers Squibb K.K., Chugai Pharmaceutical Co., Ltd., Eli Lilly Japan K.K., Mitsubishi-Tanabe Pharma Co., Ono Pharmaceutical, Pfizer Japan Inc., Takeda Pharmaceutical Co. Ltd., and UCB Japan Co. Ltd., Grant/research support from: TS has received research grants from AsahiKASEI Co., Ltd., Daiichi Sankyo., and Ono Pharmaceutical., Haruhito A. Uchida Grant/research support from: HAU belongs to the Department of Chronic Kidney

Disease and Cardiovascular Disease which is endowed by Chugai Pharmaceutical, MSD, Boehringer Ingelheim, and Kawanishi Holdings., Hajime Yoshifuji Speakers bureau: HY has received lecture fees from Chugai Pharmaceutical Co., Ltd. and Nihon Medi-Physics Co., Ltd., Yasuhiro Maejima Speakers bureau: YM have received honoraria from Chugai Pharmaceutical Co., Ltd.., Taio Naniwa Speakers bureau: TN has received lecture fees from Chugai Pharmaceutical Co., Ltd.., Grant/research support from: TN has received research grants from Chugai Pharmaceutical Co., Ltd.., Yasuhiro Katsumata Speakers bureau: YK has received honoraria from Chugai Pharmaceutical Co., Ltd., Glaxo-Smithkline K.K., Sanofi K.K., Pfizer Japan Inc., and Asahi Kasei Pharma Corp., Takahiro Okazaki Grant/research support from: TO has received research grants from Chugai Pharmaceutical Co., Ltd., Eisai Pharmaceutical., and Actelion, Jun Ishizaki: None declared, Yohko Murakawa Speakers bureau: YM has received honoraria from Abbvie, Astellas, Ayumi Pharmaceutical, Bristol Myers Squibb, Chugai Pharmaceutical, Eisai Pharmaceutical, Janssen Pharmaceutical, Kissei Pharmaceutical, Nippon Kayaku, Pfizer Pharmaceutical, Takeda Pharmaceutical, UCB Pharmaceutical, Grant/research support from: YM has received research grant support from Asahi Kasei Pharma, AbbVie Japan, Chugai Pharmaceutical, Daiichi Sankyo, Eisai Pharmaceutical, Mitsubishi Tanabe Pharma, Nippon Kayaku, Gilead Sciences Inc, Janssen Pharmaceutical, and Teijin Pharma., Noriyoshi Ogawa: None declared, Hiroaki Dobashi: None declared, Tetsuya Horita: None declared, Yoshiya Tanaka Speakers bureau: YT has received consulting fees, speaking fees, and/or honoraria from Daiichi-Sankyo, Astellas, Pfizer, Mitsubishi-Tanabe, Bristol-Myers, Chugai, YL Biologics, Eli Lilly, Sanofi, Janssen, UCB, Grant/research support from: YT has received research grants from Mitsubishi-Tanabe, Takeda, Bristol-Myers, Chugai, Astellas, Abbvie, MSD, Daiichi-Sankyo, Pfizer, Kyowa- Kirin, Eisai, Ono., Shunsuke Furuta: None declared, Tsutomu Takeuchi Speakers bureau: TT has served on speakers’ fees for AbbVie, Bristol-Myers Squibb, Chugai, Mitsubishi Tanabe, Pfizer, Astellas, Daiichi Sankyo, Eisai, Sanofi, Teijin, Takeda, and Novartis., Consultant of: TT has received consulting fees from Astra Zeneca, Eli Lilly, Novartis, Mitsubishi Tanabe, AbbVie, Nippon Kayaku, Janssen, Astellas, Taiho, Chugai, Taisho Toyama, GlaxoSmithKline, and UCB., Grant/research support from: TT has received research grants from Astellas, Chugai, Daiichi Sankyo, Takeda, AbbVie, Asahi Kasei, Mitsubishi Tanabe, Pfizer, Eisai, AYUMI, Nippon Kayaku, and Novartis., Yoshinori Komagata Speakers bureau: YK has received speakers’ fees from Bristol-Myers Squibb, Eli Lilly, Janssen, Novartis, Daiichi Sankyo, AbbVie, Nippon Shinyaku, Towa., Consultant of: YK has received consulting fees from Chugai, Kyowa Hakko Kirin, Asahi Kasei, UCB, Yoshikazu Nakaoka Speakers bureau: YN has received lecture fees from Astellas, Takeda, Daiichi Sankyo, Actelion, and Japan Blood Products Organization (JB)., Consultant of: YN has received consulting fees and/or lecture fees from AbbVie and Chugai, Grant/research support from: YN has received research grants from Chugai and Bayer Yakuhin, Ltd, masayoshi harigai Speakers bureau: MH has received speaker’s fee from AbbVie Japan GK, Ayumi Pharmaceutical Co., Boehringer Ingelheim Japan, Inc.,Bristol Myers Squibb Co., Ltd., Chugai Pharmaceutical Co., Ltd., Eisai Co., Ltd., Eli Lilly Japan K.K., GlaxoSmithKline K.K., Kissei Pharmaceutical Co., Ltd., Pfizer Japan Inc., Takeda Pharmaceutical Co., Ltd., and Teijin Pharma Ltd., Consultant of: MH is a consultant for AbbVie, Boehringer-ingelheim, Bristol Myers Squibb Co., Kissei Pharmaceutical Co.,Ltd. and Teijin Pharma., Grant/research support from: MH has received research grants from AbbVie Japan GK, Asahi Kasei Corp., Astellas Pharma Inc., Ayumi Pharmaceutical Co., Bristol Myers Squibb Co., Ltd., Chugai Pharmaceutical Co., Daiichi-Sankyo, Inc.,Eisai Co., Ltd., Kissei Pharmaceutical Co., Ltd., Mitsubishi Tanabe Pharma Co., Nippon Kayaku Co., Ltd., Sekiui Medical, Shionogi & Co., Ltd., Taisho Pharmaceutical Co., Ltd., Takeda Pharmaceutical Co., Ltd., and Teijin Pharma Ltd.

POS0975 CLINICAL CHARACTERISTICS OF NONRADIOGRAPHIC AXIAL SPONDYLOARTHRITIS IN ASIAN COUNTRIES COMPARED TO OTHER REGIONS: RESULTS OF THE INTERNATIONAL CROSS-SECTIONAL ASAS-COMOSPA STUDY

Background:

Clinical characteristics of nonradiographic axial spondyloarthritis (nr-ax-SpA) are highly variable across patients, and may potentially vary across patient populations, particularly due to differing distributions of human leukocyte antigens (HLA) and other genetic factors. The majority of nr-ax-SpA studies have been conducted in Europe, the United States, and small studies are reported from Asia [1].

Objectives:

To delineate clinical characteristics of patients with nr-ax-SpA in Asian countries in comparison to other areas of the world.

Methods:

Utilizing the ASAS-COMOSPA data, an international cross-sectional observational study of SpA patients, we analyzed information on demographics, disease characteristics, comorbidities, and risk factors. Patients were classified by region: Asia (China, Japan, Singapore, South Korea, and Taiwan), and non-Asian countries (Europe, Americas, and Africa); patient characteristics, including diagnosis and treatment, were compared.

Results:

Among 3984 SpA patients included in the study, 1094 were from centers in Asian countries, and 2890 from other regions. 112/780 (14.4%) of axial SpA patients in Asian countries were nr-ax-SpA, substantially less than in other countries (486/1997, 24.3%). Nr-ax-SpA patients in Asian countries compared to nr-ax-SpA in other countries were more likely male (75.9 vs 47.1%), have onset (22.8 vs 27.8 years) and diagnosis (27.2 vs 34.5 years) at younger age, and experience less diagnostic delay (1.88 vs 2.92 years) (Table 1). Nr-ax-SpA patients in Asian countries have higher prevalence of positive HLA-B27 (90.6% vs 61.9%) and fewer peripheral signs such as arthritis, enthesitis, or dactylitis (53.6% vs 66.3%) but have similar rate of extra-articular manifestations (psoriasis, IBD, or uveitis) and co-morbidities. Disease activity, functional impairment, and inflammation on MRI were less in nr-ax-SpA patients in Asian countries. NSAIDs response was higher and use of methotrexate and b-DMARDs were lower among nr-ax-SpA in Asian countries.

Conclusion:

Among axial SpA patients, substantially lower frequency of nr-ax-SpA was observed in Asian countries compared to other regions of the world. Nr-ax-SpA patients in Asian countries were predominantly male, and had younger disease onset with higher HLA-B27 positivity rate and less peripheral signs, and better response to NSAIDs. These results offer an opportunity to improve both early diagnosis and treatment of nr-ax-SpA patients in Asian countries.

Table 1.

Characteristics of nonradiographic axial SpA in Asia versus non-Asian regions

VariablesAsianon-Asian regionsp valueN112486Age at disease diagnosis, yrs27.2 [21.1, 39.6]34.5 [27.7, 41.7]<0.001Diagnostic delay, yrs1.88 [0.27, 5.56]2.92 [0.59, 9.58]0.011Male (%)85 (75.9)229 (47.1)<0.001Sacroiliitis on MRI among tested (%)49 (67.1)341 (82.2)0.005HLA B27 positivity among measured (%)96 (90.6)273 (61.9)<0.001Inflammatory Back Pain (%)107 (95.5)478 (98.4)0.076Arthritis, enthesitis, or dactylitis (%)60 (53.6)322 (66.3)0.016Psoriasis (%)12 (10.7)82 (16.9)0.142Uveitis (%)20 (17.9)81 (16.7)0.870Inflammatory bowel disease (%)5 (4.5)27 (5.6)0.817Elevated CRP (%)37 (33.0)213 (43.8)0.048Physician global assessment (0-10)2.0 [1.0, 5.0]2.0 [1.0, 4.0]0.741Patient global assessment (0-10)3.0 [1.0, 6.0]4.0 [2.0, 6.0]0.012ASDAS-CRP1.40 [0.95, 2.08]1.97 [1.21, 2.78]<0.001BASFI0.8 [0.05, 2.65]2.9 [0.8, 5.6]<0.001Good response to NSAIDs (%)80 (71.4)272 (56.0)0.004Methotrexate use (%)18 (16.1)134 (27.6)0.016Biological DMARDs use (%)27 (24.1)191 (39.3)0.004

References:

[1]López-Medina C, Ramiro S, van der Heijde D, et al. Characteristics and burden of disease in patients with radiographic and non-radiographic axial Spondyloarthritis: a comparison by systematic literature review and meta-analysis. RMD Open. 2019 Nov 21;5(2): e001108.

Acknowledgements:

This study was conducted under the umbrella of the International Society for Spondyloarthritis Assessment (ASAS) and COMOSPA study was supported by unrestricted grants from Pfizer, AbbVie and UCB.

Disclosure of Interests:

Keisuke Ono: None declared, Mitsumasa Kishimoto Speakers bureau: AbbVie, Amgen-Astellas BioPharma, Asahi-Kasei Pharma, Astellas, Ayumi Pharma, BMS, Chugai, Daiichi-Sankyo, Eisai, Eli Lilly, Gilead, Janssen, Kyowa Kirin, Novartis, Ono Pharma, Pfizer, Tanabe-Mitsubishi, Teijin Pharma, and UCB Pharma, Consultant of: AbbVie, Amgen-Astellas BioPharma, Asahi-Kasei Pharma, Astellas, Ayumi Pharma, BMS, Chugai, Daiichi-Sankyo, Eisai, Eli Lilly, Gilead, Janssen, Kyowa Kirin, Novartis, Ono Pharma, Pfizer, Tanabe-Mitsubishi, Teijin Pharma, and UCB Pharma, Sho Fukui: None declared, Satoshi Kawaai: None declared, Gautam A. Deshpande: None declared, Kazuki Yoshida Consultant of: OM1, Inc., Grant/research support from: Corrona, LLC, Naomi Ichikawa: None declared, Yuko Kaneko Speakers bureau: AbbVie, Astellas, Ayumi, Bristol-Myers Squibb, Chugai, Eisai, Eli Lilly, Hisamitsu, Jansen, Kissei, Pfizer, Sanofi, Takeda, Tanabe-Mitsubishi, and UCB, Taku Kawasaki: None declared, Kazuo Matsui: None declared, Mitsuhiro Morita: None declared, Kurisu Tada: None declared, Naoho Takizawa: None declared, Naoto Tamura: None declared, Atsuo Taniguchi: None declared, Yoshinori Taniguchi: None declared, Shigeyoshi Tsuji: None declared, Shigeto Kobayashi: None declared, Masato Okada: None declared, Clementina López-Medina: None declared, Anna Moltó Consultant of: AbbVie, Pfizer, MSD, Novartis, Gilead, Lilly and UCB, Grant/research support from: AbbVie, Pfizer, MSD, Novartis, Gilead, Lilly and UCB, Désirée van der Heijde Consultant of: AbbVie, Amgen, Astellas, AstraZeneca, Bayer, BMS, Boehringer Ingelheim, Celgene, Cyxone, Daiichi, Eisai, Eli-Lilly, Galapagos, Gilead, Glaxo-Smith-Kline, Janssen, Merck, Novartis, Pfizer, Regeneron, Roche, Sanofi, Takeda, UCB Pharma, Employee of: Imaging Rheumatology bv. (Director), Maxime Dougados: None declared, Yoshinori Komagata: None declared, Tetsuya Tomita: None declared, Shinya Kaname: None declared.

Oral tolerance

Oral administration of antigen results in immune tolerance which is mediated by anergy, deletion or the generation of regulatory cells, depending on the dose of antigen administered. Regulatory cells which secrete anti-inflammatory cytokines such as TGF-beta lead to bystander suppression at the target organ of the antigen fed. Oral administration of autoantigens has been shown to suppress autoimmune diseases in several animal models and is being tested as a potential therapy in human autoimmune and other inflammatory diseases.

Resistance to fulminant hepatitis and carcinogenesis conferred by overexpression of retinoblastoma protein in mouse liver

Previously, retinoblastoma (Rb) transgenic mice were produced under the control of the Rb gene promoter and showed dwarf characteristics. Here, we created transgenic mice, in which the human Rb gene was controlled by the hepatocyte nuclear factor-1 gene promoter/enhancer and was expressed primarily in the liver. The liver of these novel transgenic mice was normally developed. Intriguingly, these mice showed resistance to fulminant hepatitis induced by anti-Fas antibody as well as resistance to chemical carcinogenesis in the liver. These results show that the Rb protein acts as an anti-apoptotic and anti-oncogenic agent in vivo. Our novel construct may be useful as a gene cassette in gene therapy for prevention of fulminant hepatitis and hepatoma.

Suppression of collagen-induced arthritis by oral or nasal administration of type II collagen

We directly compared the effects of oral and nasal administration of collagen type II (CII) on disease progression, cytokine production and T cell responses in DBA/1 mice. Lymphocytes were assayed for proliferation and cytokine production and cell lines established. T cells from fed or nasally treated groups proliferated significantly less and produced markedly less IFN-gamma than the non-fed immunized group 10 days after immunization and prior to onset of arthritis. T cell lines established from fed or nasally treated mice showed a pattern of cytokine production involving IL-4, IL-10 and TGF-beta, whereas T cell lines from the control group produced more IFN-gamma and IL-2. Suppression of clinical measures of arthritis was equivalent in the nasal and orally treated groups. Animals were then tested for IFN-gamma production 70 days after a booster immunization at a time when disease was apparent. Mucosally treated animals secreted less IFN-gamma as compared to controls, even at this late time point. Suppression of collagen induced arthritis (CIA) by nasal treatment of mice with CII was associated with diminished levels of TNF-alpha and IL-6 mRNA expression in the joints of tolerized mice, two cytokines known to be involved in the inflammatory and pathological process of CIA. These results demonstrate the induction of antigen specific Th2 and TGF-beta secreting regulatory cells following both oral and nasal treatment, which is associated with suppression of local inflammation in the joints and decreased Th1 type responses in the periphery throughout the course of the illness.

Altered expression level of a systemic nuclear autoantigen determines the fate of immune response to self

One of the hallmarks of systemic autoimmune diseases is immune responses to systemic nuclear autoantigens. We have examined the fate of the immune response against a nuclear autoantigen using human U1 small nuclear ribonucleoprotein-A protein (HuA) transgenic (Tg) mice by adoptive transfer of autoreactive lymphocytes. We obtained two Tg lines that have different expression levels of the transgene. After spleen cells from HuA-immunized wild-type mice were transferred to Tg mice and their non-Tg littermates, these recipients were injected with HuA/IFA to induce a recall memory response. HAB69, which expressed a lower amount of HuA, exhibited a vigorous increase in the autoantibody level and glomerulonephritis. Moreover, the autoreactivity spread to 70K autoantigen. Alternatively, in HAB64, which expressed a higher amount of HuA, the production of autoantibody was markedly suppressed. The immune response to HuA autoantigen was impaired as demonstrated in a both delayed-type hypersensitivity response and proliferation assay. This inhibition was Ag-specific and was mediated by T cells. These data suggest that the expression level of systemic autoantigens influences the outcome of the immune response to self.

IL-4 is a differentiation factor for transforming growth factor-beta secreting Th3 cells and oral administration of IL-4 enhances oral tolerance in experimental allergic encephalomyelitis

We have previously shown that following oral administration of myelin basic protein (MBP), regulatory T cells are generated from gut-associated lymphoid tissue and that these cells suppress experimental allergic encephalomyelitis (EAE). These regulatory T cells produce transforming growth factor-beta (TGF-beta) with various amounts of IL-4 and IL-10 and these TGF-beta-secreting T cells have been termed Th3 cells. T cells in lymphoid organs drained by mucosal sites secrete IL-4 as a primary T cell growth factor. In the present study, we examined the role of IL-4 on oral tolerance and in the generation of TGF-beta secreting cells. Treatment of (PLJ x SJL)F1 mice with intraperitoneal (i. p.) IL-4 and low-dose oral MBP (0.5 mg) given three times reduced the severity of EAE, whereas i.p. injection of IL-4 alone or oral MBP alone given in these suboptimal doses, showed no protection. Spleen cells from protected mice produced increased amounts of TGF-beta and reduced IFN-gamma upon stimulation with MBP in vitro. Mucosal MBP-specific IgA production was significantly increased in IL-4 plus MBP fed animals. Moreover, oral administration of IL-4 (1 microg per feeding) also enhanced the suppression of EAE by oral MBP and this protective effect was reversed by administration of anti-TGF-beta antibody in vivo. Reverse transcription-PCR showed enhanced suppression of IFN-gamma in Peyer's patch in animals fed MBP and IL-4 versus those fed MBP alone. We then investigated the role of IL-4 in the generation of TGF-beta-secreting cells using MBP Ac1-11 TCR transgenic animals. Cells were cultured with IL-2, IL-4, or IFN-gamma in the presence of MBP and limiting dilution analysis for cytokine-secreting cells performed. We found that IL-4, but not IL-2 or IFN-gamma, generated TGF-beta-secreting T cells from naive splenic T cells and that these cells provided help for IgA production. These findings demonstrate that IL-4 is a differentiation factor for TGF-beta-secreting Th3 cells and oral IL-4 has a synergistic effect on low-dose oral tolerance that is associated with increased TGF-beta secretion.

IL-4 is a differentiation factor for transforming growth factor-beta secreting Th3 cells and oral administration of IL-4 enhances oral tolerance in experimental allergic encephalomyelitis

We have previously shown that following oral administration of myelin basic protein (MBP), regulatory T cells are generated from gut-associated lymphoid tissue and that these cells suppress experimental allergic encephalomyelitis (EAE). These regulatory T cells produce transforming growth factor-beta (TGF-beta) with various amounts of IL-4 and IL-10 and these TGF-beta-secreting T cells have been termed Th3 cells. T cells in lymphoid organs drained by mucosal sites secrete IL-4 as a primary T cell growth factor. In the present study, we examined the role of IL-4 on oral tolerance and in the generation of TGF-beta secreting cells. Treatment of (PLJ x SJL)F1 mice with intraperitoneal (i. p.) IL-4 and low-dose oral MBP (0.5 mg) given three times reduced the severity of EAE, whereas i.p. injection of IL-4 alone or oral MBP alone given in these suboptimal doses, showed no protection. Spleen cells from protected mice produced increased amounts of TGF-beta and reduced IFN-gamma upon stimulation with MBP in vitro. Mucosal MBP-specific IgA production was significantly increased in IL-4 plus MBP fed animals. Moreover, oral administration of IL-4 (1 microg per feeding) also enhanced the suppression of EAE by oral MBP and this protective effect was reversed by administration of anti-TGF-beta antibody in vivo. Reverse transcription-PCR showed enhanced suppression of IFN-gamma in Peyer's patch in animals fed MBP and IL-4 versus those fed MBP alone. We then investigated the role of IL-4 in the generation of TGF-beta-secreting cells using MBP Ac1-11 TCR transgenic animals. Cells were cultured with IL-2, IL-4, or IFN-gamma in the presence of MBP and limiting dilution analysis for cytokine-secreting cells performed. We found that IL-4, but not IL-2 or IFN-gamma, generated TGF-beta-secreting T cells from naive splenic T cells and that these cells provided help for IgA production. These findings demonstrate that IL-4 is a differentiation factor for TGF-beta-secreting Th3 cells and oral IL-4 has a synergistic effect on low-dose oral tolerance that is associated with increased TGF-beta secretion.

Abrogation of autoimmune diabetes in nonobese diabetic mice and protection against effector lymphocytes by transgenic paracrine TGF-beta1

Paracrine effect of transforming growth factor-beta1 (TGF-beta1) on autoimmune insulitis and diabetes was studied by transgenic production of the active form of porcine TGF-beta1 (pTGF-beta1) in pancreatic islet (islet) alpha cells in nonobese diabetic (NOD) mice under the control of rat glucagon promoter (RGP) (NOD-RGP-TGF-beta1). None of 27 NOD-RGP-TGF- beta1 mice developed diabetes by 45 wk of age, in contrast to 40 and 71% in male and female nontransgenic mice, respectively. None of the NOD-RGP-TGF-beta1 mice developed diabetes after cyclophosphamide (CY) administration. Adoptive transfer of splenocytes of NOD-RGP-TGF-beta1 mice to neonatal NOD mice did not transfer diabetes after CY administration. Adoptive transfer of three types of diabetogenic lymphocytes to NOD-RGP-TGF-beta1 and nontransgenic mice after CY administration led to the lower incidence of diabetes in NOD-RGP-TGF-beta1 mice versus that in nontransgenic mice: 29 vs. 77% for diabetogenic splenocytes, 25 vs. 75% for islet beta cell-specific Th1 clone cells, and 0 vs. 50% for islet beta cell-specific CD8(+) clone cells, respectively. Based on these, it is concluded that autoimmune diabetes in NOD mice is not a systemic disease and it can be completely prevented by the paracrine TGF-beta1 in the islet compartment through protection against CD4(+) and CD8(+) effector lymphocytes.

In situ immune response in gut-associated lymphoid tissue (GALT) following oral antigen in TCR-transgenic mice

Oral administration of Ag results in systemic hyporesponsiveness termed oral tolerance. The regulatory cells induced by oral Ag are effective in the suppression of Th1-type autoimmune diseases. We examined the cytokine microenvironment in gut-associated lymphoid tissue in response to orally administered OVA in OVA TCR-transgenic mice. Mice were fed a low (0.5 mg) or high (500 mg) dose of OVA one time or five times. Immunohistochemical analysis demonstrated increased IL-4, IL-10, and TGF-beta in the gut within 6 h of a low-dose feeding and after five low-dose or high-dose feedings. IFN-gamma and IL-2 either decreased or showed no change, with the exception of a small transient increase in IL-2 at 6 h after a low dose. Increases in IL-4 and IL-10 were found in the dome of the Peyer's patch, and increases in TGF-beta were observed in the interfollicular region and the villi. IL-10 was also substantially increased in the villi. IL-4 and IL-10 were produced predominately by CD4+ T cells. TGF-beta was found predominately in macrophages and CD4+ T cells. Peyer's patches had a marked up-regulation of TGF-beta mRNA as measured by RT-PCR. These results demonstrate the differential activation of cytokine production in discrete regions of gut-associated lymphoid tissue. The induction of cytokines known to inhibit autoimmune disease at the site of Ag absorption indicates an important role for the mucosal immune system in the establishment of oral tolerance.

[Fundamental studies on antibacterial activity of clindamycin against Propionibacterium acnes]

Antibacterial activity of clindamycin against Propionibacterium acnes (P. acnes) was evaluated in comparison with nadifloxacin in vitro. Using a burned-infected mouse model, topical application of 1% gel form of clindamycin phosphate on P. acnes was also evaluated in in vivo. (1) The MIC of clindamycin measured by agar dilution method was 0.02 microgram/ml, and this value was smaller than that of nadifloxacin (0.3 microgram/ml). (2) At concentrations on 1-, 2- and 4- times the MIC clindamycin demonstrated bacteriostatic activity on P. acnes and showed bactericidal activity at 5-times the MIC. Nadifloxacin showed bacteriostatic activity at one half the MIC and bactericidal activity at the MIC. (3) Against acquired resistant strains of P. acnes, the highest concentrations of clindamycin and nadifloxacin that did not inhibit growth of the organism increased 5-fold higher than those against sensitive strain during 25 successive cultures in vitro. Therefore, the resistance of P. acnes was found to be emerged at almost the same ratio against both agents. (4) The chemotherapeutic effects of 1% gel form of clindamycin phosphate and 1% cream of nadifloxacin were evaluated for given subcutaneously to infected P. acnes at the burned site in mice. The topical application of either agents showed a significant reduction of number of bacteria and this result predicted clinical efficacy of topical application of clindamycin.

Reduced T helper 1 responses in IL-12 p40 transgenic mice

To investigate the antagonistic effect of IL-12 p40 on IL-12 activity in vivo, we generated transgenic (Tg) mice in which p40 gene was regulated by a liver-specific promoter. Three Tg mouse lines were generated, and they expressed the p40 transgene predominantly in liver. Serum p40 level was extremely high, and it consisted of mainly monomer and homodimer and also of higher m.w. complexes. These Tg mice did not show any apparent phenotypic difference from control littermates in lymphoid cells. Enhancement of NK cell lytic activity in spleen by administration of rIL-12 to these mice was greatly diminished. Ag induced cytokine production was impaired: decreased production of IFN-gamma and increased production of IL-4 and IL-10. Delayed-type hypersensitivity response was also significantly reduced. Moreover, these Tg mice showed increased susceptibility to the infection with an intracellular pathogen, blood-stage Plasmodium berghei XAT, which is an irradiation-induced attenuated substrain of P. berghei NK65, presumably due to the decreased IFN-gamma production. These results suggest that p40 functions as an IL-12 antagonist in vivo, and that Th1 responses in p40 Tg mice are significantly reduced. Thus, these Tg mice could be a useful model to evaluate the inhibitory effect of p40 on IL-12-mediated various immune responses in vivo.

Role of cytosolic phospholipase A2 in allergic response and parturition

Phospholipase A2 (PLA2) comprises a superfamily of enzymes that hydrolyse the ester bond of phospholipids at the sn-2 position. Among the members of this superfamily, cytosolic PLA2 has attracted attention because it preferentially hydrolyses arachidonoyl phospholipids and is activated by submicromolar concentrations of Ca2+ ions and by phosphorylation by mitogen-activated protein kinases (MAP kinases). Here we investigate the function of cytosolic PLA2 in vivo by using homologous recombination to generate mice deficient in this enzyme. These mice showed a marked decrease in their production of eicosanoids and platelet-activating factor in peritoneal macrophages. Their ovalbumin-induced anaphylactic responses were significantly reduced, as was their bronchial reactivity to methacholine. Female mutant mice failed to deliver offspring, but these could be rescued by administration of a progesterone-receptor antagonist to the mother at term. Considered together with previous findings, our results indicate that cytosolic PLA2 plays a non-redundant role in allergic responses and reproductive physiology.

Developmentally ordered V-J recombination in mouse T cell receptor gamma locus is not perturbed by targeted deletion of the Vgamma4 gene

Mouse TCR gamma genes in the gamma1 cluster are arranged in the order of Vgamma5, Vgamma2, Vgamma4, Vgamma3, Jgamma1, and Cgamma1 on the chromosome. During thymic ontogeny, each Vgamma gene recombines with the Jgamma1 gene in the order of proximity to Jgamma1. To explore the mechanism of the ordered recombination, we generated Vgamma4-deficient mice by gene targeting and the Cre/loxP system, by deleting the 4.8-kb DNA region between 3' of the Vgamma2 and 3' of the Vgamma4. In semiquantitative PCR analysis, Vgamma2-Jgamma1 recombination was detected frequently in adult thymus, while Vgamma3-Jgamma1 recombination preferentially occurred in fetal thymus of the mutant mice. There was no difference in the frequency of V-J recombinations between control and mutant mice. Southern blot analysis also revealed that recombination of the Vgamma2 gene occurred as frequently as in control mice. In addition, there was no difference in the levels of germline transcripts of Vgamma2 and Vgamma3 genes between control and mutant mice. Therefore, regulation of the Vgamma-Jgamma recombination was not affected by deletion of the Vgamma4 gene. These results suggest that the ordered recombination is controlled by regulatory elements near each Vgamma gene.

Developmentally ordered V-J recombination in mouse T cell receptor gamma locus is not perturbed by targeted deletion of the Vgamma4 gene

Mouse TCR gamma genes in the gamma1 cluster are arranged in the order of Vgamma5, Vgamma2, Vgamma4, Vgamma3, Jgamma1, and Cgamma1 on the chromosome. During thymic ontogeny, each Vgamma gene recombines with the Jgamma1 gene in the order of proximity to Jgamma1. To explore the mechanism of the ordered recombination, we generated Vgamma4-deficient mice by gene targeting and the Cre/loxP system, by deleting the 4.8-kb DNA region between 3' of the Vgamma2 and 3' of the Vgamma4. In semiquantitative PCR analysis, Vgamma2-Jgamma1 recombination was detected frequently in adult thymus, while Vgamma3-Jgamma1 recombination preferentially occurred in fetal thymus of the mutant mice. There was no difference in the frequency of V-J recombinations between control and mutant mice. Southern blot analysis also revealed that recombination of the Vgamma2 gene occurred as frequently as in control mice. In addition, there was no difference in the levels of germline transcripts of Vgamma2 and Vgamma3 genes between control and mutant mice. Therefore, regulation of the Vgamma-Jgamma recombination was not affected by deletion of the Vgamma4 gene. These results suggest that the ordered recombination is controlled by regulatory elements near each Vgamma gene.

Efficient removal of loxP-flanked DNA sequences in a gene-targeted locus by transient expression of Cre recombinase in fertilized eggs

The bacteriophage P1 Cre/loxP site-specific recombination system is a useful tool for engineering chromosomal changes in animal cells. Transient expression of the Cre recombinase gene directly introduced into fertilized eggs by pronuclear injection has been reported to provide an efficient method of transgene modulation in fertilized eggs. In the present study, we examined the efficacy of this method to remove loxP-flanked DNA sequences in a gene-targeted locus in fertilized eggs. We replaced a part of the T-cell receptor gamma (TCR V gamma) locus with homologous sequences containing a loxP-flanked neogene in mouse embryonic stem (ES) cells by gene-targeting technique. The resulting ES cell clones containing the mutant allele (V gamma LNL) were used to generate chimeric mice by blastocyst injection. Eight male chimeras were bred with superovulated wild-type female mice. One hundred and seventy-six fertilized eggs were collected, and subjected to pronuclear injection of the Cre expression plasmid, pCAGGS-Cre, of a covalently closed circular form. Three out of 11 pups inherited the targeted V gamma locus. The inherited targeted allele of these 3 mice was shown to have undergone Cre-mediated recombination, resulting in a deletion of the loxP-flanked sequences (V gamma delta) as shown by Southern blot analysis of DNA from tail biopsies. All 3 founder mutant mice were capable of transmitting the V gamma delta locus to their offspring. The other 8 pups carried only wild-type alleles. There were no pups carrying the unrecombined V gamma LNL locus. Thus, the frequency of Cre-mediated recombination was 100% (3/3) with this method. In contrast, when closed circular pCAGGS-Cre plasmid was introduced into ES cells by electroporation, the recombination frequency of the V gamma LNL locus was 9.6%. These results indicated that our system based on transient expression of the Cre recombinase gene directly introduced into fertilized eggs by pronuclear injection provides a fast and efficient method for generating mutant mice with desired deletions or translocations in target genes.

The effect of adriamycin against a liver metastatic model by encapsulation in liposomes

Antitumor activities of liposomes containing adriamycin (L-ADM) and their distribution process into tumour cells were analysed. The lipid composition of the liposomes was dimyristoylphosphatidylglycerol (DMPG)/egg phosphatidylcholine/cholesterol/adriamycin (ADM) in a molar ratio of 11.4:2:12:1.3. Liver-metastasizing murine tumour models, M5076 and L5178Y-ML, were used. In vivo antitumour effect against these tumour models was assessed from increase in life span (ILS). The survival prolongation effect of L-ADM in mice with liver failure caused by M5076 was significantly higher than that of F-ADM. In contrast, significant enhancement of the effects by encapsulation in liposomes was not observed in L5178Y-ML-bearing mice. In vitro cytostatic activities of L-ADM against M5076 cells as well as against other tumour cell lines were lower than those of F-ADM. The in vitro kinetic study on the distribution of L-ADM to the tumour cells revealed that ADM in L-ADM was taken up into the tumour cells mainly after it was released from the liposomes rather than taken up as the liposomal form. Among the cell lines tested, M5076 cells had the highest phagocytic activity and therefore the highest uptake activity of ADM during incubation with L-ADM. These findings suggest that the augmented antitumour activity of L-ADM in M5076-bearing mice was the result of phagocytosis of L-ADM by M5076 cells as well as the reduction of toxicity, prolonged retention of ADM in systemic circulation, and liver accumulation of ADM after administration of L-ADM.

Interleukin 7 receptor-deficient mice lack gammadelta T cells

The interleukin 7 receptor (IL-7R) plays a crucial role in early B- and T-cell development. It consists of a unique a chain and a common gamma chain [IL-2 receptor gamma chain (IL-2Rgamma)]. Gene inactivation of IL-7, IL-7R, and IL-2Rgamma resulted in severe impairment of B and T lymphopoiesis in mice. In addition, IL-2Rgamma-deficient mice lack gammadelta T cells in the skin and have the impaired development of natural killer (NK) cells and intraepithelial lymphocytes. To explore the role of IL-7/IL-7R system in gammadelta T- and NK-cell development, we have generated and analyzed IL-7R-deficient mice. gammadelta T cells were absent from skin, gut, liver, and spleen in the deficient mice. In contrast, alphabeta T and B cells were detected in reduced, but certain, numbers, and NK cells developed normally. The gammadelta T-cell development in fetal and adult thymus was also completely blocked. These results clearly demonstrate that the signal from IL-7R is indispensable for gammadelta T-cell development in both thymic and extrathymic pathways. On the contrary, it is suggested that NK-cell development requires cytokine(s) other than IL-7.

Clonal prevalence of T cells infiltrating into the pancreas of prediabetic non-obese diabetic mice

The non-obese diabetic (NOD) mouse spontaneously develops T-cell-mediated autoimmune insulitis. We analyzed the clonotypes of T cell infiltrates of the NOD mouse islets using a new method we have developed recently, which consists of RT-PCR amplification of the CDR3 region of the TCR beta chain mRNA and subsequent single-strand conformation polymorphism (SSCP) analysis. NOD mice of 10-32 weeks of age were shown to accumulate oligoclonal T cells in the pancreas. To examine whether each T cell clone stays in a small area of the pancreas or spreads over the whole pancreas, a pancreas was divided into two pieces, which were then subsequently analyzed in a pair by the above PCR-SSCP method. When a pair produces common bands with the same mobility in SSCP gel, they are likely to represent the presence of the same T cell clones between these two parts of the pancreas. Aged mice (24-32 weeks old) with severe insulitis obviously produced more common bands for most of the Vbeta subfamilies than younger mice (10 weeks old) with only periinsulitis. DNA sequencing verified that these common bands have the same TCR junctional sequences, suggesting that they were derived from the same T cell clones. These results suggest that clonal prevalence of T cells infiltrating into the pancreas occurs in the late stage of insulitis development and that a limited number of T cell clones finally predominate over the whole pancreas.

Heterogeneity of N insertion capacity in fetal hematopoietic stem cells

TCR gene rearrangement is strictly regulated during mouse ontogeny. The V-(D)-J junctions of alphabeta and gammadelta TCR transcripts expressed in the adult thymus are more highly diverse than those in the fetal thymus. We previously showed that adult hematopoietic stem cells (HSC) have a higher capacity to insert N nucleotides into Vgamma4 TCR transcripts than fetal HSC and that the level of N nucleotide insertion is determined, at least in part, at the level of HSC. To analyze this developmental change of HSC at the single cell level, we investigated N nucleotide insertions in three TCR transcripts (Vgamma4, Vgamma2 and Vbeta8) derived from limiting numbers of fetal liver HSC by fetal thymic organ culture. Eight day-14 fetal liver HSC clones showed various levels of N nucleotide insertions in Vgamma transcripts (0-78%). On the other hand, the level of N insertions was similarly regulated in Vgamma4, Vgamma2, and Vbeta8 TCR transcripts in a clone-specific way. These results suggested that the level of N insertion is programmed at the level of single HSC and that fetal liver contains a heterogeneous population of HSC in terms of N insertion capacity. After 3 weeks culture with a stromal cell line, fetal HSC showed higher levels of N insertion capacity than before culture. This result and the presence of HSC with intermediate N insertion capacity support the hypothesis that the developmental potential of individual HSC gradually changes from fetal to adult type in one stem cell lineage.

[Production and characterization of a monoclonal antibody specific for Salmonella O19-antigen]

A monoclonal antibody, SBY1 (IgM, kappa), against the Salmonella O-antigen was generated by using the myeloma cell line Sp2/O-Ag14 as a fusion partner with spleen cells from BALB/c mice immunized with S. senftenberg 963 K. SBY1 was characterized by the slide agglutination and absorption test. SBY1 was believed to show the specificity to O1-, O3- or O19-antigens of Salmonella because S. Senftenberg 963 K (O1, 3, 19) was used as the antigen for immunization. The slide agglutination test with the Salmonella serovars indicated the responsiveness of SBY1. SBY1 was reactive only with strains that possessed O19-antigen. The agglutinating ability of SBY1 was absorbed completely with bacilli possessing O19-antigen. These finding indicates that SBY1 is specific for O19-antigen. Polyclonal factor sera for he serotyping of the O3, 10 group of Salmonella cross-reacted with Salmonella group O1, 3, 19 in the slide agglutination test. In contrast, SBY1 did not cross-react with serovars from several other Salmonella groups. These data suggest the usefulness of SBY1 as a serodiagnostic tool for serotyping of Salmonella.

T cell dependent and independent steps in IgE-B memory cell development

The role of T cells in the IgE antibody response was studied using athymic nu/nu mice which failed to form IgE antibody against either T-dependent or T-independent antigens. Evidence was obtained that hapten-specific B cells can be primed with T-dependent or T-independent antigens in the absence of T cells. Transfer of nu/nu spleen cells primed with alum-absorbed dinitrophenyl (DNP) ovalbumin or DNP derivatives of Salmonella bacilli into irradiated nu/+ mice, together with unprimed T cells, enhanced IgE antihapten antibody response of the recipients to alum-absorbed DNP-KLH. The antigen-primed nu/nu spleen cells, however, did not contain hapten-specific B memory cells directly committed to IgE response, since no antihapten IgE antibody response was obtained when the same DNP-primed nu/nu spleen cells were transferred into irradiated mice, together with KHL-primed nu/+ spleen cells, and the recipients were challenged with DNP-KLH without adjuvant. Once IgE-B memory cells responded to DNP derivatives of both T-dependent and T-independent carriers to form a significant amount of antihapten IgE antibody without participation of T cells. The results indicate that the essential role of T helper cells in the IgE antibody response is in the process of the development of IgE-B memory cells.