[Show abstract][Hide abstract] ABSTRACT: A growing body of evidence indicates that genetic factors are involved in an increased risk of infection. We investigated whether mannose-binding lectin (MBL) gene polymorphisms that cause low levels of MBL are associated with the occurrence of major infections in patients, mainly bearing hematological malignancies, after high-dose chemotherapy (HDT) rescued by autologous peripheral blood stem cell transplantation (auto-PBSCT). A retrospective evaluation of 113 patients treated with HDT and auto-PBSCT revealed that the low-producing genotypes, B/B and B/LXA, were associated with major bacterial infection (P=0.0016, OR 7.9). We next performed a nation-wide large-scale study to assess the allele frequency of the MBL coding mutation in a total of 2623 healthy individuals in Japan. The frequency of allele B was estimated to be approximately 0.2, almost the same in seven different areas of Japan. This common occurrence suggests that MBL deficiency may play an important role in the clinical settings of immunosuppression.
Genes and Immunity 04/2005; 6(2):162-6. · 3.68 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A case of inherited homozygous complement C3 deficiency (C3D) in a patient with systemic lupus erythematosus (SLE) and the molecular basis for this deficiency are reported. A 22-year-old Japanese male was diagnosed as having SLE and his medical history revealed recurrent tonsillitis and pneumonia. He was diagnosed as having C3D because of undetectable serum C3 level. His parents were consanguineous. Sequence analysis of C3D cDNA revealed a homozygous deletion of exon 39 (84bp). A single base substitution (AG to GG) in the 3'-splice acceptor site of intron 38 was identified by sequencing the genomic DNA. Expression of C3Delta(ex39) cDNA, the C3cDNA lacking exon 39, in COS-7 cells revealed that C3Delta(ex39) was retained in endoplasmic reticulum-Golgi intermediate compartment because of defective secretion. These data indicate that a novel AG-->GG 3'-splice acceptor site mutation in intron 38 caused aberrant splicing of exon 39, resulting in defective secretion of C3.
Biochemical and Biophysical Research Communications 04/2005; 330(1):298-304. · 2.41 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Molecular defects of TNFRSF1A was investigated in members of a family presenting with typical phenotypes of tumor necrosis factor receptor-associated periodic syndrome (TRAPS) and in patients with the autoimmune disorders, systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). Genomic DNA from the members of a family with typical TRAPS, as well as from 100 patients with SLE, 100 patients with RA and 100 healthy individuals, was studied for mutations in exons 2, 3 and 4 of the TNFRSF1A gene. All individuals were Japanese. Three novel missense mutations were identified in the TNFRSF1A. The C70G mutation was identified in family members with typical TRAPS, which was the second case in eastern Asian population. In addition, the T61I and R104Q mutations were each identified in 2 of the 100 SLE patients. The T61I mutation was identified in one of the 100 healthy individuals. No mutations were identified in the 100 RA patients. Functional analysis revealed that PMA-induced shedding of TNFRSF1A from PBMCs was impaired in a patient carrying T61I. A larger scale of study will clarify whether these two mutations, T61I and R104Q, are associated with chronic inflammatory disorders, such as SLE, or not.
International Journal of Molecular Medicine 12/2004; 14(5):813-8. · 1.96 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Systemic lupus erythematosus (SLE) is a highly prevalent human autoimmune diseases that causes progressive glomerulonephritis, arthritis and an erythematoid rash. Mice deficient in deoxyribonuclease I (Dnase1) develop an SLE-like syndrome. Here we describe two patients with a heterozygous nonsense mutation in exon 2 of DNASE1, decreased DNASE1 activity and an extremely high immunoglobulin G titer against nucleosomal antigens. These data are consistent with the hypothesis that a direct connection exists between low activity of DNASE1 and progression of human SLE.
[Show abstract][Hide abstract] ABSTRACT: Mannose binding lectin (MBL) deficiency may be associated with increased susceptibility to infection and autoimmune disorders, such as systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). In the present study, we performed for the first systematic search for mutations in all the four exons of the MBL gene using polymerase chain reaction (PCR)/single-strand conformation polymorphism (SSCP) analysis. Of 49 healthy Japanese individuals studied, only the previously reported mutation at the codon 54 (substitution from Gly to Asp; G54D) was identified. The allele frequencies of G54D in 105 healthy Japanese individuals, 95 SLE patients and 59 RA patients, were 0.233, 0.226 and 0.178, respectively, which were not significantly different. In addition, two polymorphisms at positions of -550 and -221 in the promoter region were not associated with SLE and RA. It is unlikely that MBL deficiency plays a major role in the pathogenesis of SLE and RA in Japanese.
Genes and Immunity 11/2000; 1(7):464-6. · 3.68 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Caspase-8 is an apical and critical proteolytic enzyme in the cascade of apoptosis. As a result of alternative splicing, the generation of at least 7 isoforms of caspase-8 has been reported. The existence of multiple isoforms that lack the essential domains for apoptosis suggests the possible role of these isoforms on the regulation of apoptosis. Here we report a novel longer isoform of caspase-8 (caspase-8L) that was generated by alternative splicing of intron 8, thereby carrying a 136-bp insertion and frame shift of the transcript. The transcript encoded N-terminal two repeats of death effector domain (DED) of caspase-8, but lacking the C-terminal half of the proteolytic domain. Reverse transcriptase (RT)-polymerase chain reaction (PCR) analysis revealed the dominant expression of caspase-8L transcript compared to the intact form of caspase-8 in human peripheral blood lymphocyte (PBL) and T cells. In patients with systemic lupus erythematosus (SLE), imbalanced expression of caspase-8L transcript was identified. These results suggest the important role of caspase-8L in the modulation of apoptosis.
Biochemical and Biophysical Research Communications 07/2000; 272(3):877-81. · 2.41 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Deficiency of the seventh component of complement (C7D) is frequently associated with recurrent neisserial infections. We
report in the present study the genetic basis for C7D in a Spanish family. We used exon-specific polymerase chain reaction
(PCR)/single-strand conformation polymorphism (SSCP) analysis as a screening step for mutations, followed by direct sequencing
of the target exon. The mutation in the proband was a homozygous G-to-T transversion at nucleotide 1957, the first nucleotide
of the codon GAG for Glu-631, leading to a stop codon TAG (E631X). Our result provides further evidence that the molecular
pathogenesis of C7D is heterogeneous.
Journal of Human Genetics 01/1999; 44(3):215-218. · 2.37 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Deficiency of the ninth component of complement (C9D) is one of the most common genetic abnormalities in Japan, with an incidence of one homozygote in 1000. Although C9D individuals are usually healthy, it has been shown that they have an significantly increased risk of developing meningococcal meningitis. In the present study we report the molecular bases for C9D in 10 unrelated Japanese subjects. As a screening step for mutations, exons 2 to 11 of the C9 gene were analyzed using exon-specific PCR/single-strand conformation polymorphism analysis, which demonstrated aberrantly migrating DNA bands in exon 4 in all the C9D subjects. Subsequent direct sequencing of exon 4 of the C9D subjects revealed that eight of the 10 C9D subjects were homozygous for a C to T transition at nucleotide 343, the first nucleotide of the codon CGA for Arg95, leading to a TGA stop codon (R95X). R95X is a novel mutation different from those recently identified in a Swiss family with C9D. Cases 6 and 7 were heterozygous for the R95X mutation. Family study in case 10 confirmed the genetic nature of the defect. In case 6, the second mutation for C9D of the C9 gene was identified to be the substitution of Cys to Tyr at amino acid residue 507 (C507Y), while the genetic defect(s) in the other allele in case 7 remains unknown. Our results indicate that a novel mutation, R95X, is present in most cases of C9D in Japan.
The Journal of Immunology 03/1998; 160(3):1509-13. · 5.52 Impact Factor