Kyoko Suzuki

Molecular and Virological Evidence of Viral Activation From Chromosomally Integrated Human Herpesvirus 6A in a Patient With X-Linked Severe Combined Immunodeficiency

It has been unclear whether chromosomally integrated human herpesvirus 6 (ciHHV-6) can be activated with pathogenic effects on the human body. We present molecular and virological evidence of ciHHV-6A activation in a patient with X-linked severe combined immunodeficiency. These findings have significant implications for the management of patients with ciHHV-6.

Granulocyte colony-stimulating factor directly affects human monocytes and modulates cytokine secretion

OBJECTIVE Recent reports have indicated that monocytes express receptors for the granulocyte colony-stimulating factor (G-CSF). The direct effects of G-CSF on cytokine secretion in monocytes were examined. MATERIALS AND METHODS A monocytic cell line NOMO-1 that secretes multiple cytokines upon stimulation with lipopolysaccharide (LPS) was used. Normal human monocytes were purified by negative selection using magnetic beads. Cells pretreated with or without G-CSF were stimulated with LPS, and the subsequent concentrations of cytokines and chemokines in supernatants were determined by sandwich enzyme-linked immunosorbent assay. RESULTS NOMO-1 cells were found to express receptors for G-CSF. Although G-CSF stimulation did not induce cytokine secretion, pretreatment with G-CSF significantly attenuated LPS-stimulated secretion of the proinflammatory cytokines tumor necrosis factor-alpha and interleukin (IL)-12 in NOMO-1 cells. Simultaneously, however, G-CSF pretreatment apparently enhanced LPS-induced secretion of IL-10 and monocyte chemoattractant protein-1, whereas secretions of IL-1beta, IL-6, and IL-8 were unaffected. When normal human monocytes from healthy volunteers were similarly examined, marked individual variations in LPS-induced secretion of cytokines were observed. Although some exceptions exist, a similar tendency as to the effects of G-CSF treatment on cytokine secretions as that in NOMO-1 cells was observed in human monocytes. CONCLUSIONS Our data suggest that G-CSF directly affects monocytes and modulates their cytokine secretion. NOMO-1 cells can provide an alternate model for in vitro culture of monocytes to investigate the effects of G-CSF on cytokine secretion by these cells.

Deficiency of BLNK hampers PLC‐γ2 phosphorylation and Ca2+ influx induced by the pre‐B‐cell receptor in human pre‐B cells

B‐cell linker protein (BLNK) is a component of the B‐cell receptor (BCR) as well as of the pre‐BCR signalling pathway, and BLNK–/– mice have a block in B lymphopoiesis at the pro‐B/pre‐B cell stage. A recent report described the complete loss or drastic reduction of BLNK expression in approximately 50% of human childhood pre‐B acute lymphoblastic leukaemias (ALL), therefore we investigated BLNK expression in human pre‐B ALL cell lines. One of the four cell lines tested, HPB‐NULL cells, was found to lack BLNK expression, and we used these human pre‐B ALL cell lines that express and do not express BLNK to investigate the intracellular signalling events following pre‐BCR cross‐linking. When pre‐BCR was cross‐linked with anti‐μ heavy‐chain antibodies, significant phosphorylation of intracellular molecules, including Syk, Shc, ERK MAP kinase, and AKT, and an activation of Ras were observed without regard to deficiency of BLNK expression, suggesting that BLNK is not required for pre‐BCR‐mediated activation of MAP kinase and phosphatidyl‐inositol 3 (PI3) kinase signalling. By contrast, phospholipase C‐γ2 (PLC‐γ2) phosphorylation and an increase in intracellular Ca2+ level mediated by pre‐BCR cross‐linking were observed only in the BLNK‐expressing cells, indicating that BLNK is essential for PLC‐γ2‐induced Ca2+ influx. Human pre‐B cell lines expressing and not expressing BLNK should provide an in vitro model for investigation of the role of BLNK in the pre‐BCR‐mediated signalling mechanism.

A fetal case of transient abnormal myelopoiesis with severe liver failure in down syndrome: Prognostic value of serum markers

The authors recently encountered a lethal case of Down syndrome with transient abnormal myelopoiesis (TAM). Although the peripheral white blood cell count and blast cells had improved without specific treatment, the patient died of severe coagulopathy due to liver fibrosis when he was 5 years old. The prognosis of TAM with liver fibrosis was poor. The patient had high levels of N-terminal peptide of III procollagen, type IV collagen, and hyaluronic acid. These serum makers are noninvasive indicators of liver fibrosis and may be useful as prognostic indicators of TAM in Down syndrome.

Characterization of monocyte-macrophage-lineage cells induced from CD34+ bone marrow cells in vitro.

We characterized the expression of cell surface antigens and cytokine-secreting ability of monocyte-macrophage-lineage cells induced in vitro from CD34+ bone marrow cells. After cultivation for 3 weeks, we observed 2 distinct cell fractions: a floating small, round cell fraction and an adherent large, protruding cell fraction. Both cell fractions expressed myelocyte-monocyte-lineage antigens, but mature-macrophage markers such as CD206 were expressed only by the adherent cells. An assessment of cells cultured for 5 weeks revealed spontaneous secretion of interleukin 8 (IL-8) and IL-6, and lipopolysaccha-ride (LPS)-induced tumor necrosis factor α (TNF-α) secretion in both fractions, but only the adherent cell fraction secreted IL-10 after LPS stimulation. In contrast, both fractions of cells cultured for 3 weeks spontaneously secreted low levels of IL-8, but none of the other cytokines. Upon LPS stimulation, the cells secreted IL-6 and TNF-α, but not IL-10. We also assessed the effect of granulocyte colony-stimulating factor (G-CSF) pretreatment on TNF-α secretion by each cell fraction and found that G-CSF reduced TNF-α secretion only in the adherent fraction of cells cultured for 3 weeks. Monocyte-macrophage-lineage cells induced in vitro should provide an ideal model for functional analysis of monocyte-macrophage cells.

A Case of Morganella morganii Meningoencephatitis

Morganella morganii (M. morganii) is a Gram-negative bacillus found in the environment and among normal human intestinal flora. It is a well known cause of urinary tract infections, wound infections, sepsis and other extra-intestinal infections. It also is considered to be an opportunistic pathogen and has been known to occur both in community and nosocomial infections. Most reported cases of severe infections with M. morganii were in patients with some immunological defects. In this paper, we present a rare case in a child who had a residual cavernous hemangioma in the right frontal lobe and suffered from M. morganii meningoencephalitis.

Hematopoietic stem cell transplantation for progressive combined immunodeficiency and lymphoproliferation in patients with activated phosphatidylinositol-3-OH kinase δ syndrome type 1

Background: Activated phosphatidylinositol‐3‐OH kinase &dgr; syndrome type 1 (APDS1) is a recently described primary immunodeficiency syndrome characterized by recurrent respiratory tract infections, lymphoid hyperplasia, and Herpesviridae infections caused by germline gain‐of‐function mutations of PIK3CD. Hematopoietic stem cell transplantation (HSCT) can be considered to ameliorate progressive immunodeficiency and associated malignancy, but appropriate indications, methods, and outcomes of HSCT for APDS1 remain undefined. Objective: Our objective was to analyze the clinical manifestations, laboratory findings, prognosis, and treatment of APDS1 and explore appropriate indications and methods of HSCT. Methods: We reviewed retrospectively the medical records of cohorts undergoing HSCT at collaborating facilities. Results: Thirty‐year overall survival was 86.1%, but event‐free survival was 39.6%. Life‐threatening events, such as severe infections or lymphoproliferation, were frequent in childhood and adolescence and were common indications for HSCT. Nine patients underwent HSCT with fludarabine‐based reduced‐intensity conditioning. Seven patients survived after frequent adverse complications and engraftment failure. Most symptoms improved after HSCT. Conclusion: Patients with APDS1 showed variable clinical manifestations. Life‐threatening progressive combined immunodeficiency and massive lymphoproliferation were common indications for HSCT. Fludarabine‐based reduced‐intensity conditioning–HSCT ameliorated clinical symptoms, but transplantation‐related complications were frequent, including graft failure. GRAPHICAL ABSTRACT Figure. No caption available.