[WT1 gene expression in patients with acute myelogenous leukemia or high risk myelodysplastic syndrome successfully treated with the CAG regimen]

Ten patients with acute myelogenous leukemia or high risk myelodysplastic syndrome who had achieved complete remission following treatment with the CAG regimen were monitored for peripheral blood WT1 expression mRNA levels. Induction therapy with the CAG regimen did not seem to be enough to lower WT1 expression levels to the normal range. In comparison with patients who received intensive chemotherapy for post-remission therapy, those who received only CAG therapy showed higher levels of WT1 expression and more easily relapsed. These data suggest that CAG therapy alone might not be sufficient to maintain complete remission and WT1 monitoring could be useful in the choice of appropriate post-remission therapy after achieving remission with the CAG regimen.

Monitoring cytomegalovirus infection by antigenemia assay and two distinct plasma real-time PCR methods after hematopoietic stem cell transplantation

We compared a CMV virus load determined by real-time PCR with an antigenemia value to analyze the correlation between these two methods. We also compared the values for virus load determined by the two distinct real-time PCR methods, which amplify the US17 region and immediate-early (IE) gene of CMV, respectively, to evaluate the reliability of these methods. Two hundred and sixty-five samples were obtained weekly from 29 patients, who had engraftment after unrelated bone marrow transplantation or HLA-mismatched related blood stem cell transplantation. CMV infection was detected in 115 samples from 22 patients by US17-PCR and 69 samples from 20 patients by the antigenemia assay. Fifty-eight samples were positive for both assays, but 57 and 11 samples were positive only for US17-PCR and antigenemia, respectively. A good correlation of the results of US17-PCR and antigenemia was demonstrated (r = 0.61). All antigenemia-positive samples and randomly selected antigenemia-negative samples were subjected to IE-PCR. The results of IE-PCR showed a good correlation with those of antigenemia (r = 0.64). Furthermore, the best correlation was observed between US17-PCR and IE-PCR (r = 0.83). In conclusion, both real-time PCR methods showed a good correlation with the antigenemia assay, and could be used to monitor CMV infection after hematopoietic stem cell transplantation.

[Double t (3; 21) in acute myelomonocytic leukemia transformed from chronic myelomonocytic leukemia]

A 63-year-old male was diagnosed as chronic myelomonocytic leukemia with normal karyotype in September 1998. He developed acute myelogenous leukemia (AML-M4Eo) in September 2001. The cytogenetic analysis disclosed double t(3;21) at a ratio of 1/20, and the reverse transcriptase-polymerase chain reaction showed AML1/EVI-1 mRNA. He could not achieve complete remission after two courses of induction chemotherapy, and his leukemia cells carrying double t(3;21) were relatively increased. He died of interstitial pneumonia in December 2001. This is the first leukemia case with double t(3;21) and this chromosomal abnormality might play a role in leukemia cell proliferation by generating two AML1/EVI-1 genes.

[Molecular mechanisms in leukemogenesis]

Mutations in signal transduction molecules, which regulate cell differentiation and proliferation, are involved in the development of leukemia. Aberrations of receptor type tyrosine kinases are known to arise from FLT3 mutations in acute myeloid leukemia (AML) and myelodysplastic syndrome, and c-Kit mutations in mast cell tumors. BCR/ABL found in chronic myelogenous leukemia (CML) is a hallmark of the constitutively active forms of cytoplasmic tyrosine kinases. Downstream of the tyrosine kinase is the RAS GTP-binding protein, and genetic mutations related to this protein have been found in a wide variety of malignant tumors including hematopoietic tumors. In the nucleus, transcription factor-encoding genes are frequently detected as the targets of chromosomal translocations found in specific types of leukemias. For instance, the AML1 gene generates AML1/MTG8 chimera by t (8;21) translocation in AML (M2), AML1/EVI-1 chimera by t (3;21) translocation in blastic crisis of CML, and TEL/AML1 chimera in t (12;21) translocation (pre-B cell type acute lymphoblastic leukemia). Another example of abnormal transcription factors is PML/RAR alpha generated by t (15;17) translocation found in acute promyelocytic leukemia. Mutations or deletions of tumor suppressor genes are frequently found in cell cycle regulators such as p53, RB and p16 genes. Therefore, mutations of any molecules involved in the signal transduction pathways from growth factor receptors to inside the nucleus are thought to contribute to neoplastic transformation of hematopoietic cells.

Adenovirus as an integrating vector

Recombinant adenoviral vectors have served as one of the most efficient gene delivery vehicles in vivo thus far. Multiply attenuated or completely gutless adenoviral vectors have been developed to achieve long-term gene expression in animal models by overcoming cellular immunity against de novo synthesized adenoviral proteins. However, since adenovirus lacks native integration machinery, the goal of gene therapy obtaining permanent expression cannot be realized with current adenoviral vector systems. Recent studies have shown that replication-incompetent adenoviral vectors randomly integrate into host chromosomes at frequencies of 0.001-1% of infected cells. To improve the integration frequencies of adenoviral vectors, a variety of hybrid vectors combining the highly efficient DNA delivery of adenovirus with the integrating machinery of retroviruses, adeno-associated viruses, and transposons, have been emerging. These hybrid vectors have shown promise, at least in in vitro systems. Furthermore, adenoviral vectors have shown potential as gene targeting vectors. These developments should eventually lead to more effective gene therapy vectors that can transduce a myriad of cell types stably in vivo.

The t(3;21) fusion product, AML1/Evi-1 blocks AML1-induced transactivation by recruiting CtBP

AML1/Evi-1 is a chimeric protein that is derived from t(3;21), found in blastic transformation of chronic myelogenous leukemia. It is composed of the N-terminal AML1 portion with the DNA-binding Runt domain and the C-terminal Evi-1 portion. It has been shown to dominantly repress AML1-induced transactivation. The mechanism for it has been mainly attributed to competition with AML1 for the DNA-binding and for the interaction with PEBP2beta (CBFbeta), a partner protein which heterodimerizes with AML1. It was recently found that Evi-1 interacts with C-terminal binding protein (CtBP) to repress TGFbeta-induced transactivation. Here, we demonstrate that AML1/Evi-1 interacts with CtBP in SKH1 cells, a leukemic cell line which endogenously overexpresses AML1/Evi-1 and that AML1/Evi-1 requires the interaction with CtBP to repress AML1-induced transactivation. The association with CtBP is also required when AML1/Evi-1 blocks myeloid differentiation of 32Dcl3 cells induced by granulocyte colony-stimulating factor. Taken together, it is suggested that one of the mechanisms for AML1/Evi-1-associated leukemogenesis should be an aberrant recruitment of a corepressor complex by the chimeric protein.

Replication and packaging of helper-dependent adenoviral vectors

A helper-dependent adenovirus vector (HD AdV) that lacks all the coding sequences of viral proteins from the vector backbone was developed to overcome the problem of host cellular immune responses against E1-deleted AdV. One of the limitations of the current HD AdV system is its relatively inefficient propagation compared with that of E1-deleted AdV, which deters application of the HD AdV, especially in large animal models. We hypothesized that the low titers might be due in part to defects in replication and packaging of the vector DNA. We propagated two HD AdVs with similar marker gene cassettes and stuffer sequences, using two different helper viruses, and determined the replication and packaging efficiencies of viral DNA. Our analysis indicated a difference in replication and packaging efficiencies between the two vectors, which resulted in different propagation efficiencies. Furthermore, dl309, which is similar to the wild-type virus, demonstrated superior helper function over that of the loxP-containing helper virus, AdLC8cluc. These findings may have significant implications for the design of improved production systems of HD AdVs.

Mutational analyses of the AML1 gene in patients with myelodysplastic syndrome

The AML1 gene is the most frequent target of translocations associated with human leukemias. We recently found somatic point mutations of the AML1 gene, V105ter and R139G, in two cases of myelodysplastic syndrome (MDS). Both mutations are present in the region encoding the Runt domain of AML1, and cause loss of the DNA-binding ability of the resultant products. Of these mutants, V105ter has also lost the ability to heterodimerize with PEBP2beta/CBFbeta. On the other hand, the R139G mutant acts as a dominant negative inhibitor through competing with wild-type AML1 for interaction with PEBP2beta/CBFbeta. In this review, we summarize mutational changes of the AML1 gene in hematological malignancies, especially in MDS and discuss the mechanism whereby the mutant acts as a dominant negative inhibitor of wild-type AML1.

[Development of overt hemolytic anemia after splenectomy for thrombocytopenia in Evans syndrome with negative Coombs test]

A 69-year-old man was diagnosed as having idiopathic thrombocytopenic purpura (ITP) in April 2000, and treated with prednisolone (PSL) without effect. Splenectomy performed in June 2000 had only a transient and marginal influence on his platelet count. Two months later, he developed autoimmune hemolytic anemia (AIHA) without Coombs test positivity, and his diagnosis was changed to Coombs-negative Evans syndrome. Treatment with PSL led to recovery of his hemoglobin level, but not his platelet count. Although the mechanism responsible for development of AIHA after splenectomy in this patient with ITP remains unknown, close observation is required for any association with other autoimmune diseases such as SLE.

Expression of the TEL/EVI1 fusion transcript in a patient with chronic myelogenous leukemia with t(3;12)(q26;p13)

The t(3;12)(q26;p13) translocation is a recurrent chromosomal aberration observed in myeloid malignancies. It has been shown that the translocation results in the fusion of the TEL (ETV6) gene at 12p13 and the EV11 gene at 3q26. We report the first case with Philadelphia (Ph)-positive chronic myelogenous leukemia (CML) expressing the TEL/EVI1 fusion transcript. A 26-year-old man was initially diagnosed as having the chronic phase of Ph-positive CML. The t(3;12)(q26;p13) emerged 16 months prior to the myeloid blastic crisis. Reverse transcriptase-polymerase chain reaction detected the TEL/EVI1 transcript without the intervening 5' non-coding exon of EVI1, suggesting that inappropriate expression of the EVI1 protein driven by the TEL promotor could play a critical role in progression to the blast crisis of CML.

Characterization of stage progression in chronic myeloid leukemia by DNA microarray with purified hematopoietic stem cells

Chronic myeloid leukemia (CML) is characterized by the clonal expansion of hematopoietic stem cells (HSCs). Without effective treatment, individuals in the indolent, chronic phase (CP) of CML undergo blast crisis (BC), the prognosis for which is poor. It is therefore important to clarify the mechanism underlying stage progression in CML. DNA microarray is a versatile tool for such a purpose. However, simple comparison of bone marrow mononuclear cells from individuals at different disease stages is likely to result in the identification of pseudo-positive genes whose change in expression only reflects the different proportions of leukemic blasts in bone marrow. We have therefore compared with DNA microarray the expression profiles of 3456 genes in the purified HSC-like fractions that had been isolated from 13 CML patients and healthy volunteers. Interestingly, expression of the gene for PIASy, a potential inhibitor of STAT (signal transducer and activator of transcription) proteins, was down-regulated in association with stage progression in CML. Furthermore, forced expression of PIASy has induced apoptosis in a CML cell line. These data suggest that microarray analysis with background-matched samples is an efficient approach to identify molecular events underlying the stage progression in CML.

[Disease-related gene and tumor progression]

Chronic myelogenous leukemia is a stem cell tumor characterized by the t(9; 22)(q34; 11) translocation generating the BCR/ABL chimeric gene. The BCR/ABL fusion gene shows several functions, including inhibition of adhesion to stroma cells and extracellular matrix, activation of mitogenic signalings, inhibition of apoptosis, and degradation of inhibitory proteins, and thereby causes transformation of hematopoietic progenitors. Among its functions, the signal transduction pathways activated by the fusion gene are Ras and MAP kinase pathways, Jak-Stat pathways, PI3 kinase pathways, and Myc pathways. Molecular mechanisms in blastic crisis remains largely unknown. However, loss of functions of tumor suppressor genes such as p53, RB, and p16, activation of oncogene Ras, overexpression of Evi-1 might be involved in disease progression.

Characterization of anti-myocardial autoantibodies in Japanese patients with dilated cardiomyopathy

Few previous reports have comprehensively screened all the anti-myocardial autoantibodies (AMCA) in relation to other clinical profiles in patients with idiopathic dilated cardiomyopathy (IDC), so the present study used both immunohistochemistry (FITC) and immunoblotting (IB) for screening patients with IDC in order to characterize the clinical significance of AMCA. Sera were collected from 100 patients with IDC and age-matched 100 healthy control subjects (CTL). For FITC, an unfixed frozen section of human myocardium was used for the standard indirect immunofluorescence; for IB, total cardiac homogenates of the same myocardium were blotted to serum at 2 sets of dilution (1:200 and 1:10,000). The positive rates of AMCA detection for each method were as follows (IDC vs CTL); 39% vs 6% for FITC, 38% vs 4% for IB (1:200), and 10% vs 0% for IB (1:10,000). Fifty-nine patients with IDC and 8 CTL were positive for AMCA by either method, and 18 patients with IDC and 2 CTL were positive for AMCA by both methods. IB-positivity at 1:200 was an independent predictor by multiple logistic regression analysis of non-sustained ventricular tachycardias as well as left ventricular end-diastolic diameter and plasma norepinephrine concentration.

Translocation (14;19)(q32;q13) detected by spectral karyotyping and lack of BCL3 rearrangement in CD5-positive B-cell lymphoma associated with hemophagocytic syndrome

It has been shown that some cases of B-cell non-Hodgkin lymphoma associated with a hemophagocytic syndrome (B-LAHS) have chromosomal abnormalities at 14q32 or 19q13. We report here a 64-year-old woman with B-LAHS and a complex karyotype including add(14)(q32). We applied spectral karyotyping and revealed that the add(14)(q32) was derived from a der(14)t(14;19)(q32;q13). However, rearrangement of the BCL3 gene at 19q13 could not be detected by Southern blot analysis. Our results indicate that the translocation involving 19q13 may be one of the recurrent aberrations in B-LAHS and that the molecular mechanism of t(14;19)(q32;q13) in B-LAHS appear to be different from that observed in chronic lymphocytic leukemia.

Low frequency of BCL10 gene mutations in B-cell non-Hodgkin's lymphoma

The BCL10 gene was identified at the breakpoint region of the t(1;14)(p22;q32) translocation in mucosa-associated lymphoid tissue lymphoma. Initially, mutations in the BCL10 gene were reported to occur at a high frequency in various types of lymphomas and solid tumors. However, subsequent studies showed that the mutations were rarely recognized. To evaluate the frequency and spectrum of its mutations in B-cell non-Hodgkin's lymphoma (B-NHL), we screened 56 cases with B-NHL by mutation analysis of exons 2 and 3 of the gene. In addition to 2 polymorphisms, a frame-shift mutation and a missense mutation were identified in 2 cases (3.6%): 1 with diffuse large B-cell lymphoma and the other with mantle cell lymphoma. Both cases showed mutations within exon 3, resulting in a C-terminal truncation in the former and a C-terminal amino acid substitution in the latter. Reverse transcriptase-polymerase chain reaction analysis of the former case revealed that both the mutated and the wild-type alleles were transcribed with or without a sequence modification. Our results, together with recent reports, indicate that BCL10 gene mutations take place in a small population of B-NHL and are not associated with specific histological subtypes.

Oncogenic mechanisms of Evi-1 protein

Although Evi-1 is thought to promote growth or block differentiation in some cell types, its biological functions have not been elucidated. To explore the mechanisms underlying Evi-1-induced oncogenesis, we investigated whether Evi-1 affects the signaling of transforming growth factor beta (TGF-beta), which inhibits proliferation of a wide range of cell types and is one of the most studied growth regulatory factors. We demonstrated that Evi-1 represses TGF-beta signaling and antagonizes its growth-inhibitory effects. Two separate regions of Evi-1 are responsible for this repression, one of which is the first zinc-finger domain. Through this domain, Evi-1 physically interacts with Smad3, an intracellular mediator of TGF-beta signaling, thereby suppressing the transcriptional activity of Smad3. These results define a novel function of Evi-1 as a repressor of signaling components of TGF-beta. We also demonstrated that Evi-1 represses Smad-induced transcriptional activation by recruiting CtBP as a corepressor. Evi-1 associates with CtBP1 through one of the CtBP-binding consensus motifs within the region from amino acid 544 to 607, and this association is required for the efficient inhibition of TGF-beta signaling. A specific histone deacetylase (HDAc) inhibitor, trichostatin A (TSA), alleviates Evi-1-mediated repression of TGF-beta signaling, suggesting that HDAc is involved in transcriptional repression by Evi-1. This identifies a novel function of Evi-1 as a member of corepressor complexes and suggests that aberrant recruitment of corepressors is one of the mechanisms involved in Evi-1-induced leukemogenesis. These results indicate that specific HDAc inhibitors may be useful in the treatment of Evi-1-induced neoplastic tumors, including myeloid leukemias.

Argyrophilic grain disease mimicking temporal Pick's disease: a clinical, radiological, and pathological study of an autopsy case with a clinical course of 15 years

This report concerns an autopsy case of argyrophilic grain disease (AGD) mimicking temporal Pick's disease. The patient was a Japanese woman without hereditary burden who was 89 years old at the time of death. She developed memory impairment and began wandering at the age of 74, followed by prominent character changes about 6 years after disease onset. A neurological examination 5 months before her death revealed poor rapport, unconcern, severe dementia, and double incontinence, without aphasia or muscle rigidity. Serial neuroradiological examination revealed progressive enlargement of the bilateral inferior horns of the lateral ventricle, reflecting progressive atrophy of the medial temporal lobes. Macroscopically, neuropathological examination showed circumscribed atrophy of the bilateral amygdalae, hippocampi, parahippocampal gyri, and lateral occipitotemporal gyri. Histologically, there was neuronal loss in the areas mentioned above, the caudate nucleus, putamen, thalamus, substantia nigra, and locus ceruleus, with ballooned neurons in the cerebral cortex and amygdala. Numerous argyrophilic grains with coiled bodies were present not only in the limbic system, but also in the affected cerebrum. Rare neurofibrillary changes were present in the limbic areas, consistent with Braak stage II, with no senile plaques. Based on these findings and a review of the literature, we note that AGD is clinicopathologically similar not only to mesolimbocortical dementia, but also to atypical senile dementia of Alzheimer type. This report may contribute to the elucidation of the clinicopathological hallmarks of AGD.

Stable integration of transgenes delivered by a retrotransposon-adenovirus hybrid vector

Helper-dependent adenoviruses show great promise as gene delivery vectors. However, because they do not integrate into the host chromosome, transgene expression cannot be maintained indefinitely. To overcome these limitations, we have inserted an L1 retrotransposon/transgene element into a helper-dependent adenovirus to create a novel chimeric gene delivery vector. Efficient adenovirus-mediated delivery of the L1 element into cultured human cells results in subsequent retrotransposition and stable integration of the transgene. L1 retrotransposition frequency was found to correlate with increasing multiplicity of infection by the chimeric vector, and further retrotransposition from newly integrated elements was not observed on prolonged culture. Therefore, this vector, which utilizes components of low immunogenic potential, represents a novel two-stage gene delivery system capable of achieving high titers via the initial helper-dependent adenovirus stage and permanent transgene integration via the retrotransposition stage.

The corepressor CtBP interacts with Evi-1 to repress transforming growth factor beta signaling

Evi-1 is a zinc finger nuclear protein whose inappropriate expression leads to leukemic transformation of hematopoietic cells in mice and humans. This was previously shown to block the antiproliferative effect of transforming growth factor beta (TGF-beta). Evi-1 represses TGF-beta signaling by direct interaction with Smad3 through its first zinc finger motif. Here, it is demonstrated that Evi-1 represses Smad-induced transcription by recruiting C-terminal binding protein (CtBP) as a corepressor. Evi-1 associates with CtBP1 through one of the consensus binding motifs, and this association is required for efficient inhibition of TGF-beta signaling. A specific inhibitor for histone deacetylase (HDAc) alleviates Evi-1-mediated repression of TGF-beta signaling, suggesting that HDAc is involved in the transcriptional repression by Evi-1. This identifies a novel function of Evi-1 as a member of corepressor complexes and suggests that aberrant recruitment of corepressors is one of the mechanisms for Evi-1-induced leukemogenesis.

Mutations of the Smad4 gene in acute myelogeneous leukemia and their functional implications in leukemogenesis

The Smad family proteins are critical components of the transforming growth factor (TGF)-beta signaling pathway. TGF-beta is a multipotent cytokine that elicits many biological functions. In particular, TGF-beta exhibits effects on the cell cycle manifested by G1-phase arrest, differentiation, or apoptosis of several target cells, suggesting that disruption of TGF-beta signaling pathway could be involved in cancer formation. Here we show one missense mutation of the Smad4 gene in the MH1 domain (P102L) and one frame shift mutation resulting in termination in the MH2 domain (Delta(483 - 552)) in acute myelogeneous leukemia. Both of the mutated Smad4 proteins lack transcriptional activities. Concomitant expression of the P102L mutant with wild-type Smad4 inactivates wild-type Smad4 through inhibiting its DNA-binding ability. The Delta(483 - 552) mutant blocks nuclear translocation of wild-type Smad4 and thus disrupts TGF-beta signaling. This is the first report showing that mutations in the Smad4 gene are associated with the pathogenesis of acute myelogeneous leukemia and the obtained results should provide useful insights into the mechanism whereby disruption of TGF-beta signaling pathway could lead to acute myelogeneous leukemia. Oncogene (2001) 20, 88 - 96.

Nonredundant roles of the elongation factor MEN in postimplantation development

The MEN/ELL gene was cloned as a fusion partner of the MLL gene in the t(11;19)(q23;p13.1) translocation, which is found in adult myeloid leukemia. MEN belongs to a family of RNA polymerase II elongation factors and dysregulated production of MEN through the MLL promoter could cause malignant transformation of myeloid cells. To pursue the physiological role and determine the requirement of the MEN gene product in mouse development, we generated knockout mice (MEN-/-) by gene targeting in embryonic stem cells. After intercrossing heterozygous mice to generate homozygous mutants, we identified no homozygotes (MEN-/-) even at E9.5, as well as after birth, by Southern analysis. Moreover, histological examinations revealed degenerative changes in nearly one-fourth of E6.5 embryos, which were gradually resorbed by E8.5. Our findings demonstrated that MEN-/- mice are embryonic lethal, and die before E6.5 and after implantation. MEN should play a nonredundant role in postimplantation development of mice.

Mutations of the AML1 gene in myelodysplastic syndrome and their functional implications in leukemogenesis

The AML1 gene encodes a DNA-binding protein that contains the runt domain and is the most frequent target of translocations associated with human leukemias. Here, point mutations of the AML1 gene, V105ter (single-letter amino acid code) and R139G, (single-letter amino acid codes) were identified in 2 cases of myelodysplastic syndrome (MDS) by means of the reverse transcriptase-polymerase chain reaction single-strand conformation polymorphism method. Both mutations are present in the region encoding the runt domain of AML1 and cause loss of the DNA-binding ability of the resultant products. Of these mutants, V105ter has also lost the ability to heterodimerize with polyomavirus enhancer binding protein 2/core binding factor beta (PEBP2beta/CBFbeta). On the other hand, the R139G mutant acts as a dominant negative inhibitor by competing with wild-type AML1 for interaction with PEBP2beta/CBFbeta. This study is the first report that describes mutations of AML1 in patients with MDS and the mechanism whereby the mutant acts as a dominant negative inhibitor of wild-type AML1.

[Progressive limb-kinetic apraxia with myoclonus focal atrophy in the postcentral gyrus and the supplementary motor area]

We report a 70-year-old right handed man with a 5-year history of slowly progressive clumsiness of his left hand. A neurological examination disclosed mild rigidity and myoclonus in his left hand. He showed limb-kinetic apraxia, but neither ideational apraxia nor ideomotor apraxia was present. Aphasia and agnosia were also absent. He was thought to have the primary progressive limb-kinetic apraxia clinically. Brain CT and MRI revealed focal atrophy in the right postcentral gyrus and the supplementary motor area. A positron emission tomography (PET) study showed diffuse decrement of cerebral blood flow, predominantly in the right hemisphere. The decrease in the uptake of [18F]-Fluoro-deoxyglucose also revealed glucose hypo-metabolism, especially in the right frontal and parietal lobe. Striatal [11C]NMSP and [18F]FDOPA uptake were also reduced in an asymmetric pattern. These findings suggest that our patient is likely to have corticobasal degeneration. Transcranial magnetic stimulation using double pulse paradigm revealed a decrease in the level of cortico-cortical inhibition in the motor cortex on the affected side. Our results indicate increase in the excitability of motor cortical neurons in primary progressive limb-kinetic apraxia, likely due to a decreased excitability of cortico-cortical inhibitory mechanism as a result of focal degeneration of cortical neurons.

Acetylation of GATA-3 affects T-cell survival and homing to secondary lymphoid organs

Acetylation of a transcription factor has recently been shown to play a significant role in gene regulation. Here we show that GATA-3 is acetylated in T cells and that a mutation introduced into amino acids 305-307 (KRR-GATA3) creates local hypoacetylation in GATA-3. Remarkably, KRR-GATA3 possesses the most potent suppressive effect when compared with other mutants that are disrupted in putative acetylation targets. Expressing this mutant in peripheral T cells results in defective T-cell homing to systemic lymphnodes, and prolonged T-cell survival after activation. These findings have significant implications in that the acetylation state of GATA-3 affects its physiological function in the immune system and, more importantly, provides evidence for the novel role of GATA-3 in T-cell survival and homing to secondary lymphoid organs.

Real-time automated PCR for early diagnosis and monitoring of cytomegalovirus infection after bone marrow transplantation

The purpose of this study was to assess the usefulness of real-time automated PCR as a quantitative, highly reproducible, and sensitive method to detect cytomegalovirus (CMV) DNA in blood specimens. Intra- and interassay precision rates were 0.89% (small number of copies [L]), 1.43% (middle number of copies [M]), and 1.12% (high number of copies [H]), and 4.46% (L), 1.51% (M), and 2.28% (H), respectively. The linearity of this assay was obtained between 10 and 10(7) copies/well, with a minimum detection limit of 20 copies/well. Specimens from 55 of 70 healthy subjects were found to be positive for CMV antibody, but CMV DNA was not detected in any of them. In the qualitative assessment of each specimen, the results of the CMV antigenemia assay and those of the real-time PCR assay agreed in 80% (plasma specimens), 79% (all nucleated cells), and 86% (blood) of the cases examined. For eight patients diagnosed as having CMV infection or disease, no sample was positive in the antigenemia assay earlier than in the real-time PCR assay. Furthermore, the results of this assay could be obtained within 8 h. We concluded that the real-time PCR assay is useful for rapid diagnosis of CMV infection and monitoring of clinical courses.