Hidetoshi Kaneoka

Role of gammadelta T lymphocytes in the development of Behcet's disease

Phenotypic and functional properties of γδ T cells, which play an important role in mucocutaneous immunity, were examined to elucidate whether immunological abnormality in Behc¸ets disease may be related to a specific T cell population. We found that CD45RA+Vγ9+Vδ2+γδ T cells, which constitute a minor population of γδ T cells in healthy individuals, were increased in number in Behc¸ets disease irrespective of disease activity. This CD45RA+ subset of γδ T cells in the active, but not inactive, phase of this disease expressed IL‐2Rβ and HLA‐DR, suggesting that they are activated in vivo in active Behc¸ets disease. In addition, the CD45RA+γδ T cells produced extreme amounts of tumour necrosis factor and contained perforin granules. These data indicate that a phenotypically distinct subset of γδ T cells, CD45RA+CD45RO−Vγ9+Vδ2+, may contribute to immunological abnormalities which may lead to complexity of pathophysiology in Behc¸ets disease.

Role of γδ T lymphocytes in the development of Behc¸et's disease

Phenotypic and functional properties of γδ T cells, which play an important role in mucocutaneous immunity, were examined to elucidate whether immunological abnormality in Behc¸ets disease may be related to a specific T cell population. We found that CD45RA+Vγ9+Vδ2+γδ T cells, which constitute a minor population of γδ T cells in healthy individuals, were increased in number in Behc¸ets disease irrespective of disease activity. This CD45RA+ subset of γδ T cells in the active, but not inactive, phase of this disease expressed IL‐2Rβ and HLA‐DR, suggesting that they are activated in vivo in active Behc¸ets disease. In addition, the CD45RA+γδ T cells produced extreme amounts of tumour necrosis factor and contained perforin granules. These data indicate that a phenotypically distinct subset of γδ T cells, CD45RA+CD45RO−Vγ9+Vδ2+, may contribute to immunological abnormalities which may lead to complexity of pathophysiology in Behc¸ets disease.

Role of γδ T lymphocytes in the development of Behçet's disease

Phenotypic and functional properties of γδ T cells, which play an important role in mucocutaneous immunity, were examined to elucidate whether immunological abnormality in Behc¸ets disease may be related to a specific T cell population. We found that CD45RA+Vγ9+Vδ2+γδ T cells, which constitute a minor population of γδ T cells in healthy individuals, were increased in number in Behc¸ets disease irrespective of disease activity. This CD45RA+ subset of γδ T cells in the active, but not inactive, phase of this disease expressed IL‐2Rβ and HLA‐DR, suggesting that they are activated in vivo in active Behc¸ets disease. In addition, the CD45RA+γδ T cells produced extreme amounts of tumour necrosis factor and contained perforin granules. These data indicate that a phenotypically distinct subset of γδ T cells, CD45RA+CD45RO−Vγ9+Vδ2+, may contribute to immunological abnormalities which may lead to complexity of pathophysiology in Behc¸ets disease.

Effects of activin A on IgE synthesis and cytokine production by human peripheral mononuclear cells

Activin A not only stimulates the synthesis and release of pituitary follicle‐stimulating hormone, but exerts various effects on haematopoietic cells. embryos, and fibroblasts. In the present study we have examined effects of activin A on lgE synthesis and cytokine production by peripheral blood mononuclear cells (PBMC) in normal humans. When PBMC were cultured in the presence of lL ‐4, activin A significantiy augmented IgE production induced by IL‐4. Activin A did not affect, however, IgE production from highly purified B cells when they were stimulated with anti‐CD40 MoAb and IL‐4. The fact that in the latter condition IgE synthesis was T cells‐ and monocyte‐indcpcndent indicated that activin A does not directly influence B cells for IgE synthesis. Rather, production as well as gene expression of IL‐6, which is known to enhance IgE synthesis by purified monoeytes, was induced by activin A alone. In addition, activin A induced other monokines such as IL‐l and tumour necrosis factor (TNF)‐α from monocytes. In contrast, activin A neither induced nor augmented the production of TNF‐β or interferon‐gamma (IFN‐γ), both of which are known to be exclusively generated by T cells. These data indicate that activin A plays a certain role in physiological functions for monocytes in normal humans.

Functional analysis of iPSC-derived myocytes from a patient with carnitine palmitoyltransferase II deficiency

INTRODUCTION Carnitine palmitoyltransferase II (CPT II) deficiency is an inherited disorder involving β-oxidation of long-chain fatty acids (FAO), which leads to rhabdomyolysis and subsequent acute renal failure. The detailed mechanisms of disease pathogenesis remain unknown; however, the availability of relevant human cell types for investigation, such as skeletal muscle cells, is limited, and the development of novel disease models is required. METHODS We generated human induced pluripotent stem cells (hiPSCs) from skin fibroblasts of a Japanese patient with CPT II deficiency. Mature myocytes were differentiated from the patient-derived hiPSCs by introducing myogenic differentiation 1 (MYOD1), the master transcriptional regulator of myocyte differentiation. Using an in vitro acylcarnitine profiling assay, we investigated the effects of a hypolipidemic drug, bezafibrate, and heat stress on mitochondrial FAO in CPT II-deficient myocytes and controls. RESULTS CPT II-deficient myocytes accumulated more palmitoylcarnitine (C16) than did control myocytes. Heat stress, induced by incubation at 38°C, leads to a robust increase of C16 in CPT II-deficient myocytes, but not in controls. Bezafibrate reduced the amount of C16 in control and CPT II-deficient myocytes. DISCUSSION In this study, we induced differentiation of CPT II-deficient hiPSCs into mature myocytes in a highly efficient and reproducible manner and recapitulated some aspects of the disease phenotypes of CPT II deficiency in the myocyte disease models. This approach addresses the challenges of modeling the abnormality of FAO in CPT II deficiency using iPSC technology and has the potential to revolutionize translational research in this field.

Renal pathology of ANCA-related vasculitis: proposal for standardization of pathological diagnosis in Japan

BackgroundIn Japan, systematic evaluation of the histologic parameters of anti-neutrophil cytoplasmic autoantibodies (ANCA)-related vasculitis has been performed according to the Japanese classification by Shigematsu et al. However, this classification is quite different from that of the European Vasculitis Study Group (EUVAS) classification. Therefore, a histological common basis is needed to compare Japanese histological data with the international database.MethodHistological parameters concerning glomerular, tubulointerstitial, and vascular lesions of ANCA-related vasculitis, which are indispensable for clinical management, were elucidated and defined by reviewing, utilizing the merits of, and amending the two scoring systems.Results and conclusionA new comprehensive and standardized scoring system, by which histological quantitative assessment can provide evidence for therapy planning, has been developed for renal biopsy of Japanese ANCA-related vasculitis.

Mutations of carnitine palmitoyltransferase II (CPT II) in Japanese patients with CPT II deficiency

Carnitine palmitoyltransferase II (CPT II) deficiency is an inherited disorder involving β‐oxidation of long‐chain fatty acids. CPT II deficiency is a wide‐spectrum disorder that includes a lethal neonatal form, an infantile form, and an adult‐onset form. However, the ethnic characteristics and the relationship between genotype and clinical manifestation are not well understood. We investigated three non‐consanguineous Japanese patients with CPT II deficiency and examined cell lines from 4 unrelated patients and 50 healthy donors. The CPT 2 gene was typed by direct DNA sequencing of polymerase chain reaction‐amplified gene products. Case 1 (infantile form) was heterozygous for a phenylalanine to tyrosine substitution at position 383 (p.F383Y) and a novel valine to leucine substitution at 605 (p.V605L). Cases 2, 4, and 5 (infantile form) and case 3 (adult‐onset form) were heterozygous for a single mutation at F383Y. Case 6 (adult‐onset form) was compound heterozygous at the CPT 2 locus, with deletion of cytosine and thymine at residue 408, resulting in a stop signal at 420 (p.Y408fsX420), and an arginine to cysteine substitution at position 631 (p.R631C). Case 7 (adult‐onset form) was homozygous for the p.F383Y mutation. In conclusion, we identified p.F383Y mutations in six of seven patients with CPT II deficiency and two novel variants of the coding gene: p.Y408fsX420 and p.V605L. These mutations differ from those in Caucasian patients, who commonly harbor p.S113L, p.P50H, and p.Q413fsX449 mutations; therefore, our data and those of other Japanese groups suggest that the p.F383Y mutation is significant in Japanese patients with CPT II deficiency.

Suppression of Experimental Membranous Glomerulonephritis in Rats by an Anti-MHC Class II Antibody

Background: We previously reported that idiopathic membranous nephropathy (IMN) strongly correlated with HLA-DRB1*1501-DRB5*0101-DQAI*0102-DQB1* 0602, a specific haplotype of human major histocompatibility complex (MHC), in Japanese patients. To investigate the role of MHC in the development of rat Heymann nephritis (HN), an animal model of membranous nephropathy, a monoclonal antibody (mAb) specific to rat MHC class II antigen (RT1B) was administered, and its effectiveness in inhibiting HN was assessed. Methods: Active HN was induced in HN-sensitive Lewis rats by administering brush border proteins of rat proximal uriniferous tubules (FX1A). Rats were divided into four groups: rats treated with 1,000 µg anti-rat MHC class II mAb, rats treated with 100 µg anti-rat MHC class II mAb, rats treated with murine myeloma IgG, and rats that did not receive either FX1A or any other mAb. We examined the differences in 24-hour urinary protein excretion and serum alloantibody titers against FX1A between groups at different time intervals, and the histologic features of kidneys at the end of the study. Results: HN was induced in Lewis rats by inoculation with FX1A antigen. Administration of anti-MHC class II mAb successfully lowered urinary proteins, production of anti-FX1A alloantibodies, and the development of glomerular lesions in a dose-dependent manner. Conclusion: The present results demonstrated that the MHC class II molecule itself is directly involved in the pathogenesis of HN, and suggest that this therapy would be any better (or less toxic) than nonselective immunosuppressants in the treatment of IMN.

Association between HLA-DRB1*15 and Japanese patients with rheumatoid arthritis complicated by renal involvement.

We performed serological phenotyping of HLA antigens in 175 patients with rheumatoid arthritis (RA) with (n = 41) and without (n = 134) renal involvement (RI), and DNA typing of HLA class II alleles in 75 patients. Among the patients with RA, the frequency of serologically determined HLA-DR4 was found to be significantly increased (odds ratio: 1.8, confidence interval: 1.3–2.5, p = 2.4×10–4). In the patients without RI, the frequency of serological DR4 significantly increased (odds ratio: 2.2, confidence interval: 1.6–3.3, p = 2.6×10–5). On the other hand, among the patients with RI, a serological determinant, DR15, did significantly increase (odds ratio: 2.7, confidence interval: 0.9–8.4, p = 1.2×10–3) in comparison to the controls. At the DNA level, we found that the association of Japanese RA patients with serological HLA-DR4 was based on that with a genotype of HLA-DRB1*0405 (odds ratio: 2.4, confidence interval: 1.5–4.0, p = 4.4×10–4) and also found an association of HLA-DRB1*1501 (odds ratio: 2.8, confidence interval: 1.2–6.6, p = 0.017) with RA patients having RI. Our results confirmed the association of HLA-DRB1*04 with RA over the ethnic barrier at the DNA level. Our results also suggested a distinct genetic effect of HLA-DRB1*1501 in the aspect of the susceptibility of RI in RA.

A JAPANESE ADULT FORM OF CPT II DEFICIENCY ASSOCIATED WITH A HOMOZYGOUS F383Y MUTATION

Carnitine palmitoyltransferase II (CPT II) deficiency is an inherited autosomal-recessive disorder of the fatty acid metabolism.1 CPT II deficiency has three phenotypes: a lethal neonatal form, an infantile form, and an adult form. The adult form of CPT II deficiency, which is characterized by recurrent episodes of muscle pain and rhabdomyolysis, is the most common disorder of the fatty acid metabolism affecting skeletal muscles. We describe a Japanese adult form of CPT II deficiency with a homozygous F383Y mutation. The patient was a 21-year-old woman born of nonconsanguineous parents. Her brother had died as an infant, and Reye syndrome was suspected based on his liver biopsy. Her sister also died as an infant. At age 2 years, she had a hypoglycemic episode (blood sugar 9 mg/dL). When she caught a cold at age 19 years, myalgia of the right upper limb appeared and progressed rapidly to other muscles. Laboratory data showed a massively increased creatine kinase (CK) level (101,790 IU/L). Her blood urea nitrogen (BUN) was normal (19.7 mg/dL), whereas the creatinine (CREA) had increased (3.84 mg/dL). …