PubMed Health⌕ Search

Biomedical subjects

Satoru Kumaki

Publications and source records attributed to Satoru Kumaki.

14 recordsLinked to original sources
PubMed2006

Application of HSVtk suicide gene to X-SCID gene therapy: ganciclovir treatment offsets gene corrected X-SCID B cells.

Recently, a serious adverse effect of uncontrolled clonal T cell proliferation due to insertional mutagenesis of retroviral vector was reported in X-SCID gene therapy clinical trial. To offset the side effect, we have incorporated a suicide gene into therapeutic retroviral vector for selective elimination of transduced cells. In this study, B-cell lines from two X-SCID patients were transduced with bicistronic retroviral vector carrying human gamma c chain cDNA and Herpes simplex virus thymidine kinase gene. After confirmation of functional reconstitution of the gamma c chain, the cells were treated with ganciclovir (GCV). The gamma c chain positive cells were eliminated under low concentration without cytotoxicity on untransduced cells and have not reappeared at least for 5 months. Furthermore, the gamma c chain transduced cells were still sensitive to GCV after five months. These results demonstrated the efficacy of the suicide gene therapy although further in vivo studies are required to assess feasibility of this approach in clinical trial.

Antiviral Agents↗
PubMed2006

A second-site mutation in the initiation codon of WAS (WASP) results in expansion of subsets of lymphocytes in an Wiskott-Aldrich syndrome patient.

Wiskott-Aldrich syndrome (WAS) is caused by mutations in the gene encoding WAS protein (WASP ). Recently, somatic mosaicism caused by reversions or second-site mutations has been reported in some inherited disorders including WAS. In this article, we describe somatic mosaicism in a 15-year-old WAS patient due to a second-hit mutation in the initiation codon. The patient originally had a single-base deletion (c.11delG; p.G4fsX40) in the WAS (WASP) gene, which resulted in a frameshift and abrogated protein expression. Subsequently, a fraction of T and natural killer (NK) cells expressed a smaller WASP, which binds to its cellular partner WASP-interacting protein (WIP). The T and NK cells were found to have an additional mutation in the initiation codon (c.1A>T; p.M1_P5del). The results strongly suggest that the smaller WASP is translated from the second ATG downstream of the original mutation, and not only T cells but also NK cells carrying the second mutation acquired a growth advantage over WASP negative counterparts. To our knowledge, this is the first report describing somatic mosaicism due to a second-site mutation in the initiation codon of any inherited disorders.

Adolescent↗
PubMed2006

Phage phiC31 integrase-mediated genomic integration of the common cytokine receptor gamma chain in human T-cell lines.

BACKGROUND: X-linked severe combined immunodeficiency (SCID-X1, X-SCID) is a life-threatening disease caused by a mutated common cytokine receptor gamma chain (gammac) gene. Although ex vivo gene therapy, i.e., transduction of the gammac gene into autologous CD34(+) cells, has been successful for treating SCID-X1, the retrovirus vector-mediated transfer allowed dysregulated integration, causing leukemias. Here, to explore an alternative gene transfer methodology that may offer less risk of insertional mutagenesis, we employed the phiC31 integrase-based integration system using human T-cell lines, including the gammac-deficient ED40515(-). METHODS: A phiC31 integrase and a neo(r) gene expression plasmid containing the phiC31 attB sequence were co-delivered by electroporation into Jurkat cells. After G418 selection, integration site analyses were performed using linear amplification mediated-polymerase chain reaction (LAM-PCR). ED40515(-) cells were also transfected with a gammac expression plasmid containing attB, and the integration sites were determined. IL-2 stimulation was used to assess the functionality of the transduced gammac in an ED40515(-)-derived clone. RESULTS: Following co-introduction of the phiC31 integrase expression plasmid and the plasmid carrying attB, the efficiency of integration into the unmodified human genome was assessed. Several integration sites were characterized, including new integration sites in intergenic regions on chromosomes 13 and 18 that may be preferred in hematopoietic cells. An ED40515(-) line bearing the integrated gammac gene exhibited stable expression of the gammac protein, with normal IL-2 signaling, as assessed by STAT5 activation. CONCLUSIONS: This study supports the possible future use of this phiC31 integrase-mediated genomic integration strategy as an alternative gene therapy approach for treating SCID-X1.

Bacteriophages↗
PubMed2006

Delayed separation of the umbilical cord in two siblings with Interleukin-1 receptor-associated kinase 4 deficiency: rapid screening by flow cytometer.

We describe 2 siblings who had interleukin-1 receptor-associated kinase 4 deficiency with a novel mutation in exon 2. They had delayed separation of the umbilical cord. The flow cytometric analysis of monocytic intracellular tumor necrosis factor-alpha production in response to lipopolysaccharide may be a useful method to screen for the disease.

Biomarkers↗
PubMed2006

The first infant case with hepatosplenic gammadelta T-cell lymphoma after acute disseminated encephalomyelitis (ADEM)-like exacerbation.

We report the first infant case with hepatosplenic gammadelta T-cell lymphoma after recurrent acute disseminated encephalomyelitis-like, which were rapidly resolved with steroid pulse therapy. The patient had a history of recurrent bronchitis, intractable diarrhea, and failure to thrive since 4 months of age. Immunologic analysis revealed higher percentage of circulating gammadelta T-cells with markedly reduced numbers of CD3TCRalphabetaCD8 T-cells. The patient developed gammadelta T-cell lymphoma at the age of 15 months. Clinical course of the patient suggests the importance of immunological background for the development of hepatosplenic gammadelta T-cell lymphoma.

Encephalomyelitis, Acute Disseminated↗
PubMed2006

Omenn syndrome--review of several phenotypes of Omenn syndrome and RAG1/RAG2 mutations in Japan.

Omenn syndrome (OS) is a form of severe combined immunodeficiency (SCID) characterized by erythrodermia, hepatosplenomegaly, lymphadenopathy, and alopecia. In patients with OS, B cells are mostly absent, T-cell counts are normal to elevated, and T cells are frequently activated and express a restricted T-cell receptor (TCR) repertoire. Thus far, inherited hypomorphic mutations of the recombination activating genes either 1 or 2 (RAG1/2) have been detected in most OS patients. We have recently experienced a rare case of OS showing the revertant mosaicism due to multiple second-site mutations leading to typical OS clinical features with RAG1-deficient SCID. In this review, we will focus on the variation of several phenotypes of OS.

DNA-Binding Proteins↗
PubMed2004

Characterization of a novel nonsense mutation in the interleukin-7 receptor alpha gene in a Korean patient with severe combined immunodeficiency.

Although it has been suggested that defective interleukin 7 receptor (IL-7R) signaling is one of the principal causes of severe combined immunodeficiency disease (SCID) in mice and humans, little is known about the molecular and clinical characteristics of human IL-7Ralpha mutations. We report a novel mutation of the IL-7Ralpha gene in a Korean SCID patient with a greatly diminished T-cell count but normal numbers of B-cells and natural killer (NK) cells. Using direct sequencing and restriction fragment length polymorphism analysis, we identified a C-->T nucleotide change at position 638. This change resulted in a nonsense mutation (R206stop) in this patient. Both parents were heterozygous for C/T at this site. The results of this study emphasize the importance of characterization of IL-7Ralpha mutations in SCID patients with diminished T-cell numbers but normal numbers of B-cells and NK cells.

Adult↗
PubMed2004

X-linked severe combined immunodeficiency syndrome: the first Korean case with gamma c chain gene mutation and subsequent genetic counseling.

X-linked severe combined immunodeficiency (X-SCID) is a rare, life-threatening immune disorder, caused by mutations in the gamma c chain gene, which encodes an essential component of the cytokine receptors for interleukin-2 (IL-2), IL-4, IL-7, IL-9, IL-15, and IL-21. A 13-month-old boy with recurrent infections who had reduced serum immunoglobulin levels and decreased numbers of CD3, CD16/56 cells was evaluated for gamma c chain gene mutation and protein expression. The patient had a C-to-T point mutation at nucleotide position 690, one of the hot spots, resulting in a single amino acid substitution of cysteine for arginine (R226C), as determined by direct sequencing and PCR-RFLP. The patient's mother was a heterozygous carrier. Percutaneous umbilical cord blood sampling was performed at the 6-month of gestation in a subsequent pregnancy. As the immunophenotype of the fetus showed an identical pattern, the pregnancy was terminated and genetic analysis of the abortus confirmed recurrence. This is the first report of the molecular diagnosis of X-SCID in Korea. Genetic analysis of the gamma c chain gene is useful for definite diagnosis and genetic counseling for X-SCID.

Arginine↗
PubMed2003

Novel Artemis gene mutations of radiosensitive severe combined immunodeficiency in Japanese families.

A subgroup of patients with severe combined immunodeficiency (SCID) and increased cellular radiation sensitivity (RS-SCID) have mutations of Artemis, a gene that encodes a protein essential for V(D)J recombination and DNA double-strand break repair. RS-SCID described to date are either of European origin or are Athabascan-speaking native Americans belonging to the Navajo and Apache tribes. We have identified three Japanese boys and one girl from four unrelated families with RS-SCID caused by a genomic exon 3 deletion of the Artemis gene, resulting in loss of exon 3 and skipping of exon 4. Two patients were homozygous and two patients were heterozygous for this novel mutation. Those parents studied were heterozygous for this mutation. These findings suggest the genomic exon 3 deletion is unique to Japan and may be considered as a founder haplotype. Although two infants underwent successful bone marrow transplantation and immune reconstitution, the long-term outcome of this procedure is uncertain, because Artemis is expressed in most tissues and lack of its function in cells other than those derived from hematopoietic stem cells may increase the risk of malignancies.

Antigens, CD↗
PubMed2003

Hyper-IgM syndrome type 4 with a B lymphocyte-intrinsic selective deficiency in Ig class-switch recombination.

Hyper-IgM syndrome (HIGM) is a heterogeneous condition characterized by impaired Ig class-switch recombination (CSR). The molecular defects that have so far been associated with this syndrome - which affect the CD40 ligand in HIGM type 1 (HIGM1), CD40 in HIGM3, and activation-induced cytidine deaminase (AID) in HIGM2 - do not account for all cases. We investigated the clinical and immunological characteristics of 15 patients with an unidentified form of HIGM. Although the clinical manifestations were similar to those observed in HIGM2, these patients exhibited a slightly milder HIGM syndrome with residual IgG production. We found that B cell CSR was intrinsically impaired. However, the generation of somatic hypermutations was observed in the variable region of the Ig heavy chain gene, as in control B lymphocytes. In vitro studies showed that the molecular defect responsible for this new HIGM entity (HIGM4) occurs downstream of the AID activity, as the AID gene was induced normally and AID-induced DNA double-strand breaks in the switch micro region of the Ig heavy chain locus were detected during CSR as normal. Thus, HIGM4 is probably the consequence of a selective defect either in a CSR-specific factor of the DNA repair machinery or in survival signals delivered to switched B cells.

Adolescent↗
PubMed2002

The role of common gamma chain in human monocytes in vivo; evaluation from the studies of X-linked severe combined immunodeficiency (X-SCID) carriers and X-SCID patients who underwent cord blood stem cell transplantation.

Expression of common gamma chain (gammac) on monocytes was studied in five carriers of X-linked severe combined immunodeficiency (X-SCID) and two X-SCID patients who underwent cord blood stem cell transplantation (CBSCT). Flow cytometric analysis revealed that both gammac-negative and positive monocytes co-existed in X-SCID carriers, whereas no gammac-negative T, B or NK cells were observed in them. Clonal analysis and reverse transcription polymerase chain reaction studies revealed that 13.2-45.0% of monocytes from these carriers expressed the mutant gammac message. X-SCID patients who received CBSCT persistently possessed the majority of gammac-negative monocytes with a good clinical course. These results, together, may indicate that gammac is not essential for monocyte development/function in vivo.

Female↗