Koichi Kusuhara

Association of vascular endothelial growth factor (VEGF) and VEGF receptor gene polymorphisms with coronary artery lesions of Kawasaki disease.

We analyzed the genetic polymorphisms of vascular endothelial growth factor (VEGF) and its receptors [Fms-related tyrosine kinase-1, kinase insert domain receptor (KDR)] in Japanese patients with Kawasaki disease (KD) and normal control subjects to examine whether these genes would contribute to the KD occurrence and/or the development of coronary artery lesion (CAL) in KD. We found that the frequency of G allele of VEGF g.−634 G>C single-nucleotide polymorphism in the promoter region was significantly higher in KD patients with CAL than in those without CAL (p = 0.012) or control subjects (p = 0.021) because of a significantly higher frequency of the GG genotype in KD patients with CAL. In addition, the frequency of the A1 allele with 11 AC repeats of KDR g.+4422(AC)11–14 dinucleotide repeat polymorphism in intron 2 was significantly higher in KD patients with CAL than in those without CAL (p = 0.013) or control subjects (p = 0.040) as a result of a significantly higher frequency of the A1A1 genotype in KD with CAL patients. The multivariate analysis of clinical features and genotypes of the two polymorphisms showed that the A1A1 genotype of KDR g.+4422(AC)11–14 polymorphism was an independent risk factor for the development of CAL with the highest odds ratio among several clinical parameters (odds ratio 6.76; 95% confidence interval 1.05–43.48). Dual luciferase assay demonstrated that the A1 allele with KDR g.+4422(AC)11 repeats showed a weaker silencer function than the A2 allele with 12 AC repeats. These findings suggested that VEGF and its receptor, KDR, genes contributed to the development of CAL in KD patients.

Nod1 Ligands Induce Site-Specific Vascular Inflammation

Objective—The goal of this study was to investigate the effects of stimulants for a nucleotide-binding domain, leucine-rich repeat-containing (NLR) protein family on human artery endothelial cells and murine arteries. Methods and Results—Human coronary artery endothelial cells were challenged in vitro with microbial components that stimulate NLRs or Toll-like receptors. We found stimulatory effects of NLR and Toll-like receptor ligands on the adhesion molecule expression and cytokine secretion by human coronary artery endothelial cells. On the basis of these results, we examined the in vivo effects of these ligands in mice. Among them, FK565, 1 of the nucleotide-binding oligomerization domain (Nod)-1 ligands induced strong site-specific inflammation in the aortic root. Furthermore, coronary arteritis/valvulitis developed after direct oral administration or ad libitum drinking of FK565. The degree of the respective vascular inflammation was associated with persistent high expression of proinflammatory chemokine/cytokine and matrix metallopeptidase (Mmp) genes in each tissue in vivo by microarray analysis. Conclusion—This is the first coronary arteritis animal model induced by oral administration of a pure synthetic Nod1 ligand. The present study has demonstrated an unexpected role of Nod1 in the development of site-specific vascular inflammation, especially coronary arteritis. These findings might lead to the clarification of the pathogenesis and pathophysiology of coronary artery disease in humans.

Genetic Basis of Patients with Bacille Calmette-Guérin Osteomyelitis in Japan: Identification of Dominant Partial Interferon-γ Receptor 1 Deficiency as a Predominant Type

Interferon (IFN)-gamma-mediated immunity plays an important role in host defense against intracellular pathogens, especially mycobacteria. Six Japanese children with bacille Calmette-Guérin (BCG) osteomyelitis were evaluated (1 disseminated, 3 multiple, and 2 solitary types) for mutations of genes involved in interleukin-12-dependent, IFN-gamma-mediated immunity. Heterozygous small deletions with frameshift (818del4 and 811del4) that are consistent with the diagnosis of partial dominant IFN-gamma receptor 1 (IFN-gammaR1) deficiency were detected in 3 unrelated patients. Expression of IFN-gammaR1 on monocytes was significantly increased in all 3 patients. Screening of family members with recurrent and disseminated mycobacterial infections found the identical deletion in 1 of the fathers. Antimycobacterial treatment was effective in these patients and resulted in good clinical outcome. This study demonstrated that partial dominant IFN-gammaR1 deficiency was the most common in Japanese patients who showed predisposition to curable BCG osteomyelitis.

Unique activation status of peripheral blood mononuclear cells at acute phase of Kawasaki disease

Although Kawasaki disease (KD) is characterized by a marked activation of the immune system with elevations of serum proinflammatory cytokines and chemokines at acute phase, the major sources for these chemical mediators remain controversial. We analysed the activation status of peripheral blood mononuclear cells (PBMCs) by flow cytometry, DNA microarray and quantitative reverse transcription–polymerase chain reaction. The proportions of CD69+ cells in both natural killer cells and γδT cells at acute‐phase KD were significantly higher than those at convalescent‐phase KD. Microarray analysis revealed that five genes such as NAIP, IPAF, S100A9, FCGR1A and GCA up‐regulated in acute‐phase KD and the pathways involved in acute phase KD were related closely to the innate immune system. The relative expression levels of damage‐associated molecular pattern molecule (DAMP) (S100A9 and S100A12) genes in PBMCs at acute‐phase KD were significantly higher than those at convalescent‐phase KD, while those of TNFA, IL1B and IL6 genes were not significantly different between KD patients and healthy controls. Intracellular production of tumour necrosis factor‐α, interlaukin‐10 and interferon‐γ in PBMCs was not observed in KD patients. The present data have indicated that PBMCs showed a unique activation status with high expression of DAMP genes but low expression of proinflammatory cytokine genes, and that the innate immune system appears to play a role in the pathogenesis and pathophysiology of KD.

Immune response after influenza vaccination in children with cancer.

To assess the immune response to inactivated trivalent split influenza vaccine in children with cancer.

Identification of a novel type 1 diabetes susceptibility gene, T-bet

The gene encoding interferon (IFN)-γ, IFNG, is known as one of the candidate susceptibility genes for type 1 diabetes. In addition, cytokines, including IFN-γ, play important roles in the pathogenesis of type 1 diabetes. Therefore, we focused on the Th1-specific T-box transcription factor gene (T-bet), which contributes to the induction of the hallmark Th1 cytokine, IFN-γ. We first screened for polymorphisms in the T-bet gene and detected two microsatellite repeat polymorphisms located in intron 1 and the 3′- flanking region, and two single nucleotide polymorphisms, including a His33Gln substitution within the coding region. By association studies, the Gln-positive phenotype and (CA)14 allele in 3′-flanking region of T-bet were found to be associated with type 1 diabetes in the Japanese population. Furthermore, Gln33 T-bet showed a significantly higher transcriptional activity of the IFNG gene via a dual luciferase reporter assay. Our study suggests the first evidence of an association between type 1 diabetes and polymorphisms in the T-bet gene, and that variation in T-bet transcriptional activity may play a role in the development of type 1 diabetes, possibly through the effect on IFN-γ production in Th1 cells.

Association of toll-like receptor 3 gene polymorphism with subacute sclerosing panencephalitis

Innate immunity plays an important role in measles virus (MV) infection. MV-derived double-stranded RNA is recognized by toll-like receptor 3 (TLR3), retinoic acid-inducible protein I (RIG-I) and melanoma differentiation—associated gene 5 (MDA5). We investigated whether genes encoding these molecules contributed to the development of subacute sclerosing panencephalitis (SSPE) in Japanese individuals. Four single nucleotide polymorphisms (SNPs) of the three genes (TLR3 rs3775291:Leu412Phe, RIG1 rs277729 and rs9695310, and MDA5 rs4664463) were assessed in 40 SSPE patients and 84 controls. Because the TLR3 SNP showed a positive association with SSPE, three additional SNPs were subjected to haplotype analysis. The frequency of 412Phe allele of TLR3 rs3775291 in SSPE patients was significantly higher than that in controls (P=.03). In haplotype analysis of four SNPs in the TLR3 gene, the frequency of −7C/IVS3 +71C/Phe412/c.1377C haplotype was significantly increased in SSPE patients (P=.006, odds ration [OR]: 2.2). TLR3 gene may confer host genetic susceptibility to SSPE in Japanese individuals.

Tumour necrosis factor receptor-associated periodic syndrome with a novel mutation in the TNFRSF1A gene in a Japanese family

Tumour necrosis factor receptor-associated periodic syndrome (TRAPS) is a dominantly inherited disorder characterised by recurrent episodes of sustained fever. Here we report a case of TRAPS with a novel TNFRSF1A mutation, C70S, in a Japanese family. The mutation disrupts one of the three disulphide bonds in cysteine-rich domain 2 of TNF receptor 1, similar to the reported mutations of the same cysteine residue (C70R, C70Y). This is the first confirmed case of TRAPS in an eastern Asian population. The patient’s asymptomatic sister as well as their mother with mild symptoms had the same mutation. Conclusion: Although tumour necrosis factor receptor-associated periodic syndrome has been reported mainly in families of northern European ancestry, our case suggests the need to include it in the differential diagnosis of patients with recurrent fever even in ethnic groups in which no case has been documented.

Lack of association between CD28/CTLA-4 gene polymorphisms and atopic asthma in the Japanese population.

Atopic asthma occurs in genetically susceptible individuals in the presence of environmental factors. Recently, the costimulation signal from CD80-CD86 to CD28/CTLA-4 has been suggested to play an important role in the development of atopic asthma. In the present study, we analyzed three polymorphic regions within the CTLA-4 gene, an A/G substitution in exon 1 position 49, a C/T base exchange in the promoter position –318 and an (AT)n repeat polymorphism in the 3′-untranslated region of exon 4, and a CD28 gene polymorphism with a T/C substitution in intron 3 position +17 in 120 patients with atopic asthma and 200 normal controls. The polymorphism frequencies of CTLA-4/CD28 genes in patients did not differ from those in normal controls. Thus, the present study was unable to reveal any association between CTLA-4/CD28 gene polymorphisms and atopic asthma in the Japanese population.

Novel polymorphism in the 5'-untranslated region of the interleukin-4 gene.

AbstractWe found a novel polymorphism C/T change at position -34 counting from the first ATG codon, of the interleukin-4 (IL-4) gene, located between the TATA box and the first ATG on exon 1. The allelic frequency of this C/T polymorphism in 64 independent Japanese samples was 0.37 : 0.63. In addition, PCR-restriction fragment length polymorphism analysis revealed that the -34T/T polymorphism was always associated with -590T/T, a known polymorphism that increases IL-4 transcriptional activity.