Novel mutations of MVK gene in Japanese family members affected with hyperimmunoglobulinemia D and periodic fever syndrome.

Hyperimmunoglobulinemia D with periodic fever syndrome (HIDS) is a recessively inherited recurrent fever syndrome. We describe a family of eldest son and monozygotic twin younger sisters with characteristic syndrome of HIDS, but normal level of IgD. Mevalonate kinase (MK) activity was deficient in all of them, and analysis of the MVK gene revealed compound heterozygosity for 2 new mutations, one of which was the disease-causing splicing mutation and the other was a novel missense mutation. All the patients had the same compound heterozygous mutations c.227-1 G > A and c.833 T > C, which resulted in exon 4 skipping and p.Val278Ala. This is the first case in which exon skipping mutation of the MVK gene has been certainly identified at the genomic DNA level. In each case, in which HIDS is clinically suspected, despite normal IgD level, analysis of MK activity and the MVK gene should be performed.

Active fluctuation in the cortical cytoskeleton observed by high-speed live-cell scanning probe microscopy.

We investigated the dynamics of the cortical cytoskeleton in living cells by analyzing the motion of the endogenous components of the cytoskeleton using scanning probe microscopy (SPM). We performed molecular characterization of the microgranules visualized by SPM in living cells and analyzed the motion of these microgranules via particle tracking. Simultaneous SPM and epifluorescence microscopy observations showed that the microgranules recruited not only actin but also cortactin, which can bind to actin filaments. This indicates condensation of actin filaments at microgranules, leading us to identify them as "cytoskeletal microdomains". High-speed SPM observation and particle-tracking analysis showed that these cytoskeletal microdomains exhibit random walk-like diffusive fluctuations over a timescale of seconds. Inhibition of the molecular motor myosin II, which drives actin filaments, led to subdiffusive fluctuations of the microdomains. These results can be explained by longitudinal sliding of actin filaments stochastically driven by myosin II and the bending motion of the actin filaments in the absence of sliding. Analysis of the cytoskeletal microdomains thus revealed the intrinsic dynamics of the cortical cytoskeleton.

Nano-mechanical properties of living cells expressing constitutively active RhoA effectors.

Filamentous actin and myosin-II are major determinants of cell mechanics and are tightly regulated by a small guanosine triphosphatase, RhoA, and its downstream effectors. We examined the effects of constitutively active mutants of RhoA effectors, which have not been reported before, on cortical stiffness of living cells by using scanning probe microscopy, fluorescence microscopy, and truncated mutants of RhoA effectors labeled with a fluorescent protein. Our data indicated that expression of a constitutively active mutant of Dia1, a formin-family actin polymerizer, enhanced cortical stiffness and increased actin filament quantity in cells. Furthermore, expression of a constitutively active mutant of Rho-associated coiled-coil kinase, a myosin-II activator, softened the cell cortex but increased myosin-II activity. Our findings provide new insights into anomalous mechanics of cells, which is a topic of current interest in a variety of biological research fields.

NOTCH1 mutation in a female with myeloid/NK cell precursor acute leukemia.

A 6-year-old Japanese female was diagnosed as having myeloid/NK cell precursor acute leukemia (MNKL) using immunocytochemical analysis. The patient was treated by cord blood transplantation from an HLA 1-locus mismatched unrelated donor after chemotherapy comprising cytosine arabinoside, idarubicin, etoposide, and L-asparaginase. We detected a nonsense mutation, C7412A, resulting in S2471X, where X is a terminal codon, in the PEST domain of NOTCH1 in this patient. The presence of the NOTCH1 activating mutation in MNKL might suggest a possible role in the leukemogenesis of MNKL.

Dynamics of leading lamellae of living fibroblasts visualized by high-speed scanning probe microscopy.

In this study, we aimed at improving the temporal resolution of scanning probe microscopy (SPM) for observing living cells by introducing soft cantilevers, low feedback-gain operations, and cantilever deflection imaging. We achieved visualization of the mechanical architecture in leading lamellae of living fibroblasts at a temporal resolution of around 10 s, which is higher than that of conventional contact-mode SPM. Time-lapse SPM could be used to monitor not only cytoskeletal dynamics but also the dynamics of numerous microgranules. Statistical analysis of microgranular motion revealed that the microgranules have superdiffusive behaviors and significant directional order of motion. We also found that the direction of their motion is correlated with the direction of growing actin stress fibers. The combination of SPM with fluorescence microscopy showed that vinculin, a component of cell-substratum adhesion sites, localizes at the microgranules. Our experimental data provides a new insight into the intracellular mechanical architecture and its structural dynamics, suggesting that high-speed live-cell SPM has great potential for investigating the structural origin of cellular dynamics.

Mechanical response of single myoblasts to various stretching patterns visualized by scanning probe microscopy.

The mechanical memory effect of single cells was reported in our recent study. In order to clarify this effect, various sequential stimuli of uniaxial deformation were applied to cells by deformable culture dishes and a deformation device, and the local stiffness distribution of single C2C12 myoblasts was visualized by scanning probe microscopy. Following a single step stretching, cellular stiffness first increased steeply and then gradually decreased for two hours. By a single step stretching 30 min after a long pulse-like deformation with a pulse duration of 30 min, the cells responded in the same way. On the other hand, they did not respond to a single step stretching 30 min after a short pulse-like deformation with a pulse duration of 0.5 min. These results indicated that cellular mechanical response to external deformation is affected strongly by a preceding deformation and that the duration time of the preceding deformation is an important factor in the change in mechanical response. We consider that the change in mechanical response contributes to a regulatory mechanism of cellular contractile force.

Increased serum monocyte chemoattractant protein-1, macrophage inflammatory protein-1beta, and interleukin-8 concentrations in hemophagocytic lymphohistiocytosis.

BACKGROUND: Hemophagocytic lymphohistiocytosis (HLH) is characterized by hypercytokinemia caused by macrophage and T cell activation. We analyzed the serum concentrations of monocyte chemoattractant protein (MCP)-1, macrophage inflammatory protein (MIP)-1beta, and interleukin (IL)-8 to investigate the roles of these chemokines in the pathophysiology of HLH. METHODS: Seven patients clinically diagnosed with HLH were examined. Serum cytokines and chemokines were measured. The differences in the serum concentrations between the patients with HLH and the controls were investigated. RESULTS: In patients with an active phase of HLH, the serum MCP-1, MIP-1beta, and IL-8 levels all were significantly higher than in healthy controls. The chemokine elevations decreased rapidly after initiation of chemotherapy. During increases in disease activity, elevation of MCP-1 and MIP-1beta preceded elevation of the serum ferritin level, which is a clinical indicator of HLH disease activity. CONCLUSIONS: These results suggest that MCP-1, MIP-1beta, and IL-8 play important roles in the pathophysiology of HLH. In addition, the serum concentrations of these chemokines may be sensitive markers for assessing disease activity in patients with HLH.

Tandem repeats of lactoferrin-derived anti-hepatitis C virus peptide enhance antiviral activity in cultured human hepatocytes.

Previously, we found that bovine and human lactoferrin (LF) specifically inhibited hepatitis C virus (HCV) infection in cultured non-neoplastic human hepatocyte-derived PH5CH8 cells, and we identified 33 amino acid residues (termed C-s3-33; amino acid 600-632) from human LF that were primarily responsible for the binding activity to the HCV E2 envelope protein and for the inhibiting activity against HCV infection. Since the anti-HCV activity of C-s3-33 was weaker than that of human LF, we speculated that an increase of E2 protein-binding activity might contribute to the enhancement of anti-HCV activity. To test this possibility, we made two repeats [(C-s3-33)(2)] and three repeats [(C-s3-33)(3)] of C-s3-33 and characterized them. Far-Western blot analysis revealed that the E2 protein-binding activities of (C-s3-33)(2) and (C-s3-33)(3) became stronger than that of the C-s3-33, and that the binding activity of (C-s3-33)(3) was stronger than that of (C-s3-33)(2). Using an HCV infection system in PH5CH8 cells, we demonstrated that the anti-HCV activities of (C-s3-33)(2) and (C-s3-33)(3) became stronger than that of the C-s3-33. Furthermore, using a recently developed infection system with a VSV pseudotype harboring the green fluorescent protein gene and the native E1 and E2 genes, we demonstrated that the antiviral activities of (C-s3-33)(2) and (C-s3-33)(3) were stronger than that of C-s3-33. These results suggest that tandem repeats of LF-derived anti-HCV peptide are useful as anti-HCV reagents.

Prediction of intravenous immunoglobulin unresponsiveness in patients with Kawasaki disease.

BACKGROUND: In the present study, we developed models to predict unresponsiveness to intravenous immunoglobulin (IVIG) in Kawasaki disease (KD). METHODS AND RESULTS: We reviewed clinical records of 546 consecutive KD patients (development dataset) and 204 subsequent KD patients (validation dataset). All received IVIG for treatment of KD. IVIG nonresponders were defined by fever persisting beyond 24 hours or recrudescent fever associated with KD symptoms after an afebrile period. A 7-variable logistic model was constructed, including day of illness at initial treatment, age in months, percentage of white blood cells representing neutrophils, platelet count, and serum aspartate aminotransferase, sodium, and C-reactive protein, which generated an area under the receiver-operating-characteristics curve of 0.84 and 0.90 for the development and validation datasets, respectively. Using both datasets, the 7 variables were used to generate a simple scoring model that gave an area under the receiver-operating-characteristics curve of 0.85. For a cutoff of 0.15 or more in the logistic regression model and 4 points or more in the simple scoring model, sensitivity and specificity were 86% and 67% in the logistic model and 86% and 68% in the simple scoring model. The kappa statistic is 0.67, indicating good agreement between the logistic and simple scoring models. CONCLUSIONS: Our predictive models showed high sensitivity and specificity in identifying IVIG nonresponders among KD patients.

Successful rapid discontinuation of immunosuppressive therapy at molecular relapse after allogeneic bone marrow transplantation in a pediatric patient with myelodysplastic syndrome.

The success of allogeneic bone marrow transplantation (allo-BMT) in children with myelodysplastic syndrome (MDS) is mainly affected by relapse. The role of additional immunotherapy for pediatric patients with MDS relapsing after allo-BMT remains to be established. Because immunotherapy is generally more effective for patients who bear a low tumor burden, monitoring of minimal residual diseases (MRD) is essential for early diagnosis at molecular relapse. We report here that a patient with relapsed MDS after allo-BMT was successfully treated by the rapid discontinuation of immunosuppressive therapy at molecular relapse while monitoring Wilms tumor (WT1) gene expression levels. Quantitative analysis of WT1 gene expression appeared to be a useful tool to monitor MRD in the present case.

Isolation of the feline alpha1,3-galactosyltransferase gene, expression in transfected human cells and its phylogenetic analysis.

The enzyme alpha 1,3-galactosyltransferase (alpha1,3-GT), which catalyzes synthesis of terminal alpha-galactosyl epitopes (Gal alpha1,3Gal beta1-4GlcNAc-R), is produced in non-primate mammals, prosimians and new-world monkeys, but not in old-world monkeys, apes and humans. We cloned and sequenced a cDNA that contains the coding sequence of the feline alpha1,3-GT gene. Flow cytometric analysis demonstrated that the alpha-galactosyl epitope was expressed on the surface of a human cell line transduced with an expression vector containing this cDNA, and this alpha-galactosyl epitope expression subsided by alpha-galactosidase treatment. The open reading frame of the feline alpha1,3-GT cDNA is 1,113 base pairs in length and encodes 371 amino acids. The nucleotide sequence and its deduced amino acid sequence of the feline alpha1,3-GT gene are 88-90% and 85-87%, respectively, similar to the reported sequences of the bovine, porcine, marmoset and cebus monkey alpha1,3-GT genes, while they are 88% and 82-83%, respectively, similar to those of the orangutan and human alpha1,3-GT pseudogenes, and 81% and 77%, respectively, similar to the murine alpha1,3-GT gene. Thus, the alpha1,3-GT genes and pseudogenes of mammals are highly similar. Ratios of non-synonymous nucleotide changes among the primate pseudogenes as well as the primate genes are still higher than the ratios of non-primates, suggesting that the primate alpha1,3-GT genes tend to be divergent.

Formation of vesicular stomatitis virus pseudotypes bearing surface proteins of hepatitis B virus.

It has been difficult to propagate and titrate hepatitis B virus (HBV) in tissue culture. We examined whether vesicular stomatitis virus (VSV) pseudotypes bearing HBV surface (HBs) proteins infectious for human cell lines could be prepared. For this, expression plasmids for three surface proteins, L, M, and S, of HBV were made. 293T cells were then transfected with these plasmids either individually or in different combinations. 293T cells expressing HBs proteins were infected with VSVdeltaG*-G, a recombinant VSV expressing green fluorescent protein (GFP), to make VSV pseudotypes. Culture supernatants together with cells were harvested and sonicated for a short time. The infectivities of freshly harvested supernatants were determined by quantifying the number of cells expressing GFP after neutralization with anti-VSV serum and mouse monoclonal antibodies (MAbs) against HBs protein. Among 14 cell lines tested for susceptibility to HBV pseudotype samples, HepG2, JHH-7, and 293T cells were judged to be the most susceptible. Namely, the infectious units (IU) of the culture supernatant samples neutralized with anti-VSV in the absence and presence of anti-HBs S MAbs and titrated on HepG2 cells ranged from 1,000 to 4,000 IU/ml and 200 to 400 IU/ml, respectively, suggesting the presence of VSVdeltaG*(HBV) pseudotypes. This infectivity was inhibited by treatment with lactoferrin or dextran sulfate. Pretreatment of the cells with trypsin or tunicamycin inhibited plating of the pseudotype samples. The HBV pseudotypes can be used to analyze early steps of HBV infection, including the entry mechanism of HBV.

Efficient formation of vesicular stomatitis virus pseudotypes bearing the native forms of hepatitis C virus envelope proteins detected after sonication.

Hepatitis C virus (HCV) causes chronic hepatitis, liver cirrhosis and hepatocellular carcinoma in addition to acute hepatitis. The HCV genome encodes two envelope glycoproteins, E1 and E2. To investigate the role of E1 and E2 in HCV infection, we used a recombinant vesicular stomatitis virus (VSV), VSVdeltaG*, harboring the green fluorescent protein gene instead of the VSV G envelope protein gene. It was complemented with the native form of E1 and E2, or E1 or E2 alone, to make HCV pseudotypes VSVdeltaG*(HCV), VSVdeltaG*(E1), and VSVdeltaG*(E2). Neither E1 nor E2 expression was detected on the cell surface, as reported. Unlike previous reports, infectious activities of VSVdeltaG*(HCV), VSVdeltaG*(E1) and VSVdeltaG*(E2) pseudotypes were detected under conditions where VSV was completely neutralized by anti-VSV. We could enhance the infectious titers 100-fold by sonication upon virus harvest. Bovine lactoferrin efficiently inhibited infection by VSVdeltaG*(HCV) as well as VSVdeltaG*(E2), as the interaction between E2 and lactoferrin has been thought to contribute to the inhibition of HCV infectivity. VSVdeltaG*(HCV) infected many adherent cell lines, including hepatic cell lines, but not most hematopoietic cell lines. Treatment of cells with trypsin, tunicamycin, or sulfated polysaccharides before infection reduced the infectivity of VSVdeltaG*(HCV) by about 90%, suggesting that a cell surface protein(s) with sugar chains plays an important role in HCV infection. The VSV pseudotypes developed here would be useful for analyzing the early stages of HCV infection.

[Japanese nonprescription drugs (1) "Pediatric Formulas" for five kinds of "Gan"].

The genealogy of children's sedatives such as Kio-gan and Kyumei-gan, which remain in use even today for pediatric conditions including convulsions and nocturnal crying, was traced and the significance of these formulas was investigated. In the Edo Era, pediatric formulas for five kinds of gan (infantile malnutrition) combined four prescriptions to treat individual symptoms of "re (heat) gan," "leng (cool) gan," "hui (helminth parasite) gan," and "ji (spinal) gan" into one prescription. In contrast, during and after the Meiji Era, pediatric formulas for these five kinds of gan have used only one prescription to treat "re (heat) gan". Moreover, these formulas have tended to use a greater proportion of components that are used to treat "re gan". From this information, it readily became apparent that : 1) Edo Era pediatric formulas for the five kinds of gan were intended to improve the physical condition of the children prone to the illness; and, 2) modern (Meiji Era) prescriptions were intended to alleviate the acute symptoms of gan.

Linkage and association studies of STAT6 gene polymorphisms and allergic diseases.

BACKGROUND: Signal transducer and activator of transcription 6 (STAT6) is a key transcription factor involved in both interleukin-4 (IL-4) and IL-13-mediated biological responses, such as allergies. Recently, we reported that the polymorphism of the STAT6 gene exon 1 was associated with allergic diseases, while another group studied the G2964A variant of the STAT6 gene's association with atopic asthma. We undertook an association study between these variants of the STAT6 gene and allergic diseases, including atopic dermatitis, bronchial asthma, and food-related anaphylaxis in a Japanese population. METHODS: STAT6 gene polymorphisms were genotyped by polymerase chain reaction (PCR) fragment length polymorphism analysis, and PCR-SSCP analysis in 106 allergic and 66 control subjects. RESULTS: The 2964A variant was in significant linkage disequilibrium with the dinucleotide repeat polymorphism, the 13-GT repeat allele of STAT6 exon 1 (p < 0.0000000003). There was no association between the STAT6 2964A variant and allergic subjects in a Japanese population (p = 0.2724). The genotype of 13/15-GT repeat allele heterozygosity was significantly associated with allergic subjects (p = 0.0006), as previously reported. In one major genotype of the STAT6 exon 1 (15 GT repeat homozygosity), wild-type 2964G allele homozygosity was significantly associated with allergic subjects (p = 0.0382). CONCLUSIONS: Our findings indicate that in combination the dinucleotide repeat polymorphism of the STAT6 exon 1 gene and the 2964A variant may be useful markers for predicting allergic diseases in a Japanese population.